Facts and figures.

Key facts, statistics, and frequently asked questions about breast cancer.

two people with printed graphs Circling figures on table

This page brings together key facts and statistics about breast cancer, along with frequently asked questions (FAQs), to help you understand what the data shows and get clear answers to common concerns or myths.

For information on what breast cancer is and the different types of breast cancer, read our what is breast cancer? page.

 

Facts and figures. 

Global:  

UK and England:  

Incidence of breast cancer in the UK [average per year, based on 2019 and 2021-2022 data from Cancer Research UK]  

Incidence of breast cancer in England [Based on NHS England cancer registration statistics 2022]  

Incidence of breast cancer in the UK over time [data from 2018-2019 and 2021]  

From 1993-2019, breast cancer incidence in UK women rose by 26%. The increase varies by age group [9]: 

Incidence of breast cancer in England based on other demographic or genetic features  

Breast cancer risk.  

Mortality, survival and trends. 

Mortality:  

Survival rates (women in England, recent data):  

Frequently asked questions

  • Diagnosis is usually based on the results of a mammogram (breast X-ray) or an ultrasound scan of the breast. You may also require a biopsy. A breast biopsy is where a sample of cells is taken from your breast and examined under a microscope to see if abnormal or cancerous cells are present.  

    In some cases, you may also be offered a mammogram with contrast (also called contrast-enhanced spectral mammography). This type of mammogram involves injecting contrast material into your veins which allows cancers to be detected more easily on a mammogram. This is a relatively new technology in the UK and n is not currently part of the standard breast screening pathway. However, it is sometimes offered to patients whose mammograms are inconclusive. Some hospitals are now using this type of mammogram to help detect breast cancer sooner. 

    Next steps when diagnosing breast cancer may involve having further tests to find out more and decide which treatments are suitable. This may include scans, such as a CT or MRI scan, and blood tests.  

    You may not need all of the tests described here. Your GP or specialist will talk to you about any tests you need. 

  • If you notice any symptoms of breast cancer, or any changes in your breast or chest that are not normal for you, book an appointment with your GP.  They will talk to you about your symptoms. They may also ask to examine your breasts or chest. If they think your symptoms need further assessment, they will refer you to a specialist breast cancer clinic for further investigation.  

  • Q1. Is being overweight or obese a risk factor for breast cancer?

    Being overweight or obese after menopause significantly increases the risk of breast cancer. A recent analysis of 102 studies found that postmenopausal women who were obese had around a 26% higher risk of developing breast cancer compared to those of a healthy weight. 

    Excess weight is also a risk factor for breast cancer in men.

    Q2. Does being overweight or obese increase the risk of breast cancer in premenopausal women?

    Despite increasing the risk of breast cancer in postmenopausal women, weight gain and being overweight or obese does not appear to increase the risk of breast cancer in premenopausal women.

    However, young women should not intentionally gain weight to reduce their breast cancer risk. Some studies suggest that obese premenopausal women who get breast cancer tend to have more aggressive subtypes (e.g. triple-negative breast cancer). Weight gain throughout adulthood increases your risk of developing breast cancer after menopause. Additionally, weight gain and excess weight are also associated with a variety of other health risks, including cardiovascular diseases, diabetes, and other cancers.

    The reasons that excess weight before menopause does not appear to increase the risk of breast cancer are not fully understood, although they may relate to altered oestrogen levels. Oestrogen is mainly produced by the ovaries in premenopausal women and by fat tissue in postmenopausal women. In premenopausal women, evidence suggests that obesity affects the body’s hormone system in a way which reduces exposure to sex hormones, including oestrogen. After menopause, excess fat tissue increases levels of circulating oestrogens, which increases your breast cancer risk.  

    As many health risks are associated with being overweight or obese, it is important to maintain a healthy weight throughout life. 

    Q3. Is there a link between eating processed meat and breast cancer?

    There is convincing evidence that increased consumption of processed meats, such as bacon and salami, slightly increases breast cancer risk.

    Q4. Can a healthy diet help to prevent breast cancer?

    A healthy and balanced diet can help reduce your risk of breast cancer.

    While no single food can prevent breast cancer, certain dietary habits are linked to lower risk. To minimise your risk: 

    • Eat plenty of fruit and vegetables, especially non-starchy vegetables (e.g. broccoli, cauliflower, or aubergines) and those rich in carotenoids (e.g. sweet potato, tomatoes and carrots) 
    • Include foods rich in vitamin D (e.g. eggs, mushrooms or oily fish) 
    • Eating healthy fats (e.g. olive oil, nuts and avocado) 
    • Eat calcium-rich foods (e.g. milk, yoghurt and fortified plant milks) 
    • Aim for 30g of fibre a day by eating plant foods like whole grains, beans, nuts, fruit and vegetables 
    • Limit or avoid processed meats, ultra-processed foods and alcohol. 

    For further information, please visit our diet factsheet.

    Q5. Does drinking alcohol increase my breast cancer risk?

    Drinking alcohol increases the risk of breast cancer in women, and heavy alcohol consumption increases the risk in men.

    For women, the more alcohol is consumed, the greater the risk, with no safe lower limit.

    Q6. What is the ideal diet to decrease my risk of breast cancer?

    There is no ideal diet for breast cancer prevention; rather, it is more important to pay attention to the proportions of different food groups you consume on a day-to-day basis. Many diets can be help reduce your risk, including the Mediterranean diet and balanced healthy plant-based diets. 

    These diets typically focus on whole, minimally processed foods, emphasising plenty of fruits, vegetables, healthy fats and high-fibre foods, while limiting or avoiding ultra-processed foods and red or processed meats. 

    Q7. Does eating a vegan or vegetarian diet decrease breast cancer risk?

    There is growing evidence that dietary patterns rich in plant-based foods are associated with a modest reduction in breast cancer risk. Diets that emphasise vegetables, fruits, whole grains, legumes, nuts, and seeds, while limiting animal products, tend to be high in fibre, nutrients and unsaturated fats, and lower in saturated fat and overall energy density. 

    Recent research suggests that greater adherence to a healthy, plant-rich dietary pattern is linked to a lower risk of breast cancer, particularly for certain subtypes (such as oestrogen receptor-negative cancers in postmenopausal women). These benefits are thought to be driven by positive effects on body weight, inflammation, insulin sensitivity, and hormone metabolism. 

    However, not all plant-based diets are equally beneficial. While healthy plant-based diets appear to be protective, diets high in heavily processed plant foods may reduce or negate these protective effects. A healthy plant-based diet should therefore focus on whole or minimally processed foods. It’s worth noting that it’s possible to emphasise whole plant foods without eliminating animal products altogether.  

    Q8. Does eating organic food decrease my risk of getting breast cancer?

    Current research investigating the effects of organic food on breast cancer risk has so far yielded mixed results. Some studies have shown that a diet rich in organic food may reduce breast cancer risk, especially post-menopause, while others have found no link between organic food and reduced risk. 

    However, eating organic food can lower your exposure to pesticides, some of which may increase breast cancer risk. For example, the insecticide malathion and the herbicide glyphosate may increase breast cancer risk by disrupting hormones, especially oestrogen. Studies show that organic produce can reduce your pesticide exposure by around 90%. 

    The Dirty Dozen is a list of conventionally grown fruits and vegetables with the highest pesticide residues, based on PAN UK’s analysis of the UK government’s pesticide residue testing programme. To help reduce your pesticide exposure, wash produce with tap water and consider buying organic, especially for items on the Dirty Dozen list. 

    Q9. Does drinking cow’s milk increase breast cancer risk?

    Current research does not show a clear link between drinking cow’s milk and an increased risk of breast cancer. Overall, studies suggest that eating some dairy foods may be linked to a slightly lower risk, although results can vary depending on the type of dairy and the individual. 

    Some evidence indicates that low-fat and fermented dairy products, such as yogurt and kefir, may be associated with a reduced risk of breast cancer. These foods contain nutrients like calcium (which has been linked to decreased risk), and beneficial bacteria that may support gut health and reduce inflammation, although more research is needed to confirm their effects on cancer risk.  

    Concerns have been raised about the hormones found in cow’s milk and their potential effects on insulin-like growth factor 1 (IGF-1) a hormone that has been associated with a small increase in breast cancer risk. However, research to date has not found conclusive evidence to support this idea.  

    Overall, moderate consumption of dairy as part of a balanced diet may be beneficial, but more research is needed to fully understand how different dairy foods affect breast cancer risk. 

    Q10. Can vitamin D supplements reduce my breast cancer risk?

    While low levels of vitamin D have been linked to an increased breast cancer risk, most studies have not shown that taking vitamin D supplements reduces breast cancer risk. The reasons for this are unclear, and further research is needed. However, supplements can help restore circulating vitamin D levels to a healthy state and are recommended for people unable to get enough through sunshine and diet.

    Q11. Does consuming too much sugar increase breast cancer risk?

    There is currently not enough evidence to conclude that there is a link between a high-sugar diet and an increased risk of breast cancer, although some studies have suggested a possible connection.

    However,  excessive sugar intake can promote weight gain, often without the added benefit of vitamins and minerals (so-called “empty calories”) and being overweight or obese is a known risk factor for breast cancer in men and postmenopausal women.

    There is also some emerging that diets with a high glycaemic load, which cause rapid increases in blood glucose, may be associated with certain subtypes of breast cancer in postmenopausal women. Further research is needed to understand whether there is a link between sugar and breast cancer risk. 

    Q12. Does consuming products containing artificial sweeteners increase breast cancer risk?

    There is currently no evidence to suggest a strong link between artificial sweeteners and breast cancer risk.

    A 2022 study identified a link between a higher intake of certain artificial sweeteners (especially aspartame) and breast cancer risk. In July 2023, the International Agency for Research on Cancer classed the artificial sweetener aspartame as ‘possibly carcinogenic’ (group 2B). This means of the research it has reviewed; it has found limited evidence that aspartame can cause cancer.  

    However, a recent study in 2025 looking at breast cancer risk in the Nurses' Health Study (NHS) and NHS II found that aspartame consumption did not increase breast cancer risk. Therefore, the relationship between artificial sweeteners and breast cancer remains unclear, with contradictory results, and more research is required to confirm whether there is an association.  

    Despite this, it is still recommended to limit the consumption of food and drinks containing artificial sweeteners, as they have been linked to a range of other negative health impacts.  

    Q13. Does eating soy products increase breast cancer risk?

    Eating soy products does not increase breast cancer risk even though soy contains phytoestrogens. In fact, several recent studies have suggested that a diet rich in soy-based foods, such as tofu, may offer a protective effect. However, more research is needed to confirm this finding.

    Q14. Does physical activity affect my risk of breast cancer?

    Physical activity helps to lower breast cancer risk. It also helps prevent recurrence and mortality following a breast cancer diagnosis.

    Studies suggest being physically active can reduce your risk of breast cancer by around 20%. Any type of additional physical activity is beneficial; the more, the better. We recommend, as a minimum, following the World Health Organisation’s (WHO) guidelines of at least 150 minutes of moderate, or 75 minutes of vigorous, physical activity weekly.

    Q15: Does smoking increase breast cancer risk?

    Smoking is linked with a small increase in breast cancer risk. Studies suggest a 10% higher risk in women who smoke compared with those who never have, but recent research shows that this relationship is complex. Risk appears to be higher with longer duration of smoking and when smoking starts at a younger age (particularly before first pregnancy). It may also be more strongly linked to premenopausal breast cancer. Overall, smoking is considered a small but avoidable risk factor for breast cancer, and being a non-smoker has clear benefits for overall cancer risk and health. 

    Q16: Does vaping increase breast cancer risk?

    As e-cigarettes are a relatively new product, there is currently limited evidence on the link between vaping and breast cancer. While e-cigarettes do not contain tobacco - which contains several harmful chemicals and substances - they can contain some chemicals at lower levels that have previously been linked to breast cancer risk. More research is needed to establish whether vaping has an impact on breast cancer risk. 

    Q17: Does eating ultra-processed food increase my risk of breast cancer? 

    Some studies suggest that eating large amounts of ultra-processed foods may be linked to a higher risk of breast cancer. However, the evidence is still developing and results are not always consistent.  

    Several large studies have found that women with the highest intake of these foods have a modestly increased risk compared to those who eat the least, but it's difficult to separate the impact of ultra-processed foods from other lifestyle factors, such as body weight, physical activity, and overall diet quality. 

    Ultra-processed foods are often high in sugar, unhealthy fats, and additives, and low in fibre and nutrients. They may contribute to weight gain and poorer overall health, which are known to increase cancer risk.  

    Overall, while a clear cause-and-effect link has not been proven, limiting ultra-processed foods and focusing on a balanced diet based on whole or minimally processed foods is likely to support better health and may help reduce breast cancer risk. 

  • Q1. How might exposure to certain chemicals increase breast cancer risk?

    Some chemicals are harmful and can damage our DNA, known as carcinogens. Others may be harmful as they can interfere with our hormones; these are known as Endocrine (or hormone) Disrupting Chemicals (EDCs). Some EDCs can mimic the actions of the natural hormone oestrogen; exposure to high levels of this hormone increases breast cancer risk. Similarly, exposure to compounds that mimic oestrogen may also increase risk.

    For further details, visit our Chemicals factsheet.

    Q2. Where are Endocrine Disrupting Chemicals found?

    Endocrine Disrupting Chemicals (EDCs) are found in many everyday products such as cosmetics, kitchenware, plastic bottles, the lining of metal food cans, furniture and furnishings, electronics, toys, pesticides, waterproof clothing and food. They are also present in air, soil and water.

    They enter your body through eating, drinking, breathing and absorption through your skin.

    Q3. Why don’t other cancer charities highlight exposures to harmful chemicals (such as Endocrine Disrupting Chemicals) as breast cancer risk factors?

    Most cancer charities choose to prioritise other, more well-established risk factors for breast cancer over exposure to chemicals of concern, including Endocrine Disrupting chemicals (EDCs). Some charities are not yet convinced that sufficient evidence is available to demonstrate that harmful chemicals, such as EDCs that are oestrogen mimics, increase breast cancer risk. This is due to a lack of research into the effects of harmful chemicals on human health at human-relevant concentrations.

    Whilst we support the valuable work other cancer charities do, warnings from reputable scientists as well as bodies such as the United Nations Environment Programme, World Health Organisation (WHO) and the Endocrine Society suggest that chemical exposure, particularly to multiple compounds throughout life and at specific life stages does have implications for human health, including potentially increasing the risk of breast cancer.

    At Breast Cancer UK, we adopt a precautionary approach. If there is scientific evidence that a chemical has a possible link to breast cancer, we advise reducing your exposure to that chemical and lobbying for its use to be restricted or banned so that everyone is more protected.

    To find out more, visit our chemicals page in the reduce your risk section of our website.

    Q4. Does drinking water from plastic bottles increase breast cancer risk?

    Some types of plastic bottles contain bisphenols (found in polycarbonate plastics; plastic recycling code 7) or phthalates (found in recycled PET, plastic recycling code 1) which may contribute to an increased risk of breast cancer. It is very unlikely that occasional exposure to such chemicals will result in breast cancer development. However, repeatedly using plastic bottles can increase our overall exposure to chemicals known as EDCs as they can leach out into the liquids they contain, especially if heated.

    EDCs can interfere with our hormones such as oestrogen and long-term exposure to these chemicals may contribute to an increased breast cancer risk.

    Q5. Do antiperspirants and deodorants increase breast cancer risk?

    There is currently not enough conclusive evidence to say that using deodorants and antiperspirants increases breast cancer risk. Most antiperspirants contain aluminium salts which can mimic the hormone oestrogen and accumulate in breast tissue. This is why some scientists believe it may increase breast cancer risk.

    Other types of deodorants contain perfume and Endocrine Disrupting Chemicals (EDCs) such as parabens. Some of these ingredients have been shown to mimic oestrogen and may also increase the risk of breast cancer.

    It is currently unclear how long-term use of deodorants and antiperspirants affect breast cancer risk and more research is needed in this area.

    Q6. Does using products that contain essential oils increase my risk of breast cancer? 

    Essential oils are complex mixtures of potentially hundreds of different chemicals. To our knowledge, no studies have investigated whether there is an association between essential oil use and breast cancer risk. Some cell culture (laboratory) experiments have demonstrated that certain essential oils have oestrogenic properties, similar to some synthetic Endocrine Disrupting Chemicals (EDCs). 

    One small study found an association between the use of products containing lavender and tea tree oil and premature breast development in young girls, which may be a risk factor for breast cancer. Regular exposure to these oils has also been linked to abnormal breast growth in young boys, known as prepubertal gynecomastia. However, studies are still inconclusive and more research is needed. 

    Repeated use of lavender or tea tree oil may affect oestrogen levels in your body. It is important that people with oestrogen receptor-positive cancers (including breast cancer) are careful with the use of these oils. 

    We therefore recommend a cautious approach to using products that contain essential oils, particularly if you have been diagnosed with a hormone receptor-positive cancer. 

    Q7. How can I tell if personal care products contain Endocrine Disrupting Chemicals (EDCs)?

    To identify EDCs found in personal care products, we recommend using our A to Z Chemicals of Concern list. It can also help you recognise EDCs in consumer products which may be linked to breast cancer.

    Q8. What suncreams should I avoid?

    Many suncreams contain various Endocrine Disrupting Chemicals (EDCs), which we recommend you avoid. These include parabens such as propylparaben (used as preservatives) and chemical UV filters (active ingredients), for example, homosalate, ethylhexyl salicylate and butyl methoxydibenzoylmethane.  These ingredients can interfere with hormones such as oestrogen which may increase breast cancer risk. They can also cause environmental damage.

    We recommend using a mineral-based suncream that contains zinc oxide in its non-nano form (nano-form suncreams can be absorbed by the skin and may harm aquatic life). Spray and powder form suncreams should also be avoided due to the risk of inhalation.

    Our A-Z Chemicals of Concern list can help in selecting sunscreen.  However, if you do need sun protection urgently, using any suncream is better than getting sunburnt.

    Q9. Does eating food stored in plastic containers or takeaway boxes increase breast cancer risk?

    Many plastic containers and takeaway boxes, including the greaseproof linings of pizza boxes, contain Endocrine Disrupting Chemicals (EDCs) including bisphenols, phthalates and PFAS, which may, affect breast cancer risk in the long-term. 

    These chemicals can leach from containers/wrapping material into food (and the environment), leading to unintentional human exposures. The leaching process may also be accelerated under certain conditions, including high temperature (e.g., microwaving), high pH (e.g., detergents) and prolonged contact time.

    Occasional exposures to EDCs are unlikely to confer an increased breast cancer risk. However, repeated and frequent exposure to synthetic chemicals such as bisphenols, which can mimic the effects of oestrogen, may be a risk factor for breast cancer.

    In December 2024, the European Commission adopted a ban on the use of BPA and other bisphenols in food contact materials due to its potential harmful effects on human health. The UK launched a consultation on bisphenols in October 2025, the results of which support a similar ban. It is unclear when this restriction will be implemented.

    Q10. Can my child be exposed to EDCs in the womb?

    Biomonitoring studies have detected various Endocrine Disrupting Chemicals (EDCs) in the placenta, umbilical cord serum of mothers and the urine of unborn children. Furthermore, animal studies have found that exposure to EDCs in the womb (termed ‘in utero’) may increase the risk of breast cancer during adulthood. More studies are required to assess the long-term impact of chemical exposures in utero. You can read our advice for protecting your baby’s health, and more information on how exposure to chemicals in the womb can affect breast cancer risk, on our pregnancy and developing baby page.

    Q11. Does exposure to parabens affect breast cancer risk?

    Cell culture (laboratory experiments) and animal studies suggest that long-term exposure to certain parabens may increase breast cancer risk. Parabens can mimic the actions of oestrogen. They may be involved in various stages of tumour formation and growth and may contribute to the spread of cancer cells to other parts of the body. At high concentrations, they promote genotoxicity (DNA damage).

    Animal studies have found that propylparaben, at levels relevant to human exposure, can induce long-term alterations to the mammary gland, which may make animals more susceptible to mammary cancer. Methylparaben may also reduce the effectiveness of tamoxifen for treating breast cancer.

    Parabens have been measured in breast tissue and other body fluids in humans. However, most epidemiological studies have not demonstrated a link between parabens and breast cancer.

    You can find more information on our parabens and breast cancer page.

    Q12. What are microplastics and can they affect breast cancer risk? 

    Microplastics are defined as plastic pieces less than 5mm in size that are insoluble in water and can take centuries to break down completely. Primary microplastics are intentionally made for commercial purposes, such as microbeads in cosmetic products and microfibres in clothing. Secondary microplastics result from the breakdown of larger plastics and are often found polluting land and aquatic environments. These microplastics have been detected in wildlife and in human blood, breast milk and tissues.

    There is limited evidence on the link between microplastic exposure and breast cancer risk, yet it is a significant concern for human health. Microplastics may already contain harmful chemicals, but they can also absorb other chemicals and transfer them to the surrounding environment. Many of these chemicals (including bisphenols, PFAS and phthalates) have previously been linked to an increased breast cancer risk.

    Q13. What are forever chemicals? 

    Forever chemicals are per- and polyfluorinated alkyl substances (PFAS) that do not naturally break down in the environment or in our bodies. This can lead to chemical build-up in the human body, which may promote adverse health effects. Some studies have linked some PFAS with an increased risk of breast cancer.

    PFAS compounds are found in many everyday items including food packaging and clothing to make them waterproof, furniture, some cosmetics and beauty products and non-stick cookware.

    Due to their inability to break down quickly, we can still be exposed to consumer products that contain PFAS long after they have been banned. 

    You can find more information on PFAS and breast cancer risk PFAS and breast cancer page.

    Q14. What is an ‘obesogen’? 

    An obesogen is a chemical compound that can disrupt normal fat metabolism processes and may influence or promote obesity. They may act in the body by increasing the number of fat cells or increasing the storage of existing fat cells.

    Several obesogens are also Endocrine Disrupting Chemicals (EDCs). Many obesogenic EDCs including some bisphenols, phthalates and pesticides have previously been linked to breast cancer risk. The human breast contains a large proportion of fat, and many EDCs have been shown to accumulate in breast fat tissue, which could influence breast cancer development.

    Q15. What are some examples of EDCs? 

    Common examples of EDCs include bisphenols (like BPA), parabens, phthalates, PFAS ‘forever chemicals’, pesticides and flame retardants. 

    For more examples of EDCs, see our EDCs and breast cancer page.  

  • Q1. Is breast cancer during pregnancy common?

    Breast cancer during pregnancy, or pregnancy-associated breast cancer (PABC), is rare and is defined as breast cancer diagnosed during pregnancy or in the first postpartum year. It occurs in around 1 in every 3,000 pregnancies. Read more on our pregnancy and developing baby page.

    Q2. How does age at the birth of a first child affect your breast cancer risk?

    Women who have their first child over the age of 30 have an increased risk of breast cancer that lasts for around 20 years.

    Although having children at a younger age lowers the long-term risk, the first pregnancy at any age increases the short-term risk of breast cancer. Women who have recently given birth have a short-term increase in breast cancer risk for around 10 years after childbirth.

    Q3. Does breastfeeding reduce the risk of breast cancer?

    Breastfeeding lowers the risk of developing breast cancer. The longer you breastfeed, the lower your risk. Although mechanisms are not fully understood, breastfeeding changes breast tissue by eliminating cells with DNA damage and reduces the lifetime number of menstrual cycles, altering exposure to specific hormones which can influence breast cancer risk. You can read more about breastfeeding and breast cancer on our breastfeeding page.

    Q4. Does HRT cause breast cancer? 

    Whilst some forms of hormone replacement therapy, or HRT, are associated with an increase in breast cancer risk; the extent of the risk depends on the type of HRT and the duration of use.

    With oestrogen-only HRT, there is little to no increased risk of breast cancer. This type of HRT is usually only recommended to people who have had their uterus removed (hysterectomy).

    For combined HRT (oestrogen and progestogen), breast cancer risk increases when used over five years. Increased risk declines when the combined HRT treatment is stopped, but some risk remains if used for over ten years.

    Q5. Is it true that I’m more at risk if I don’t have children?

    We recognise this can be a difficult and complex area but from a risk perspective women who do not have children can be at an increased risk of breast cancer, the reasons for this are unclear but may relate to less menstrual cycles and changes in the breast tissue. 

    Q6. If I’m on a contraceptive pill or another type of hormonal contraception, am I at increased breast cancer risk?

    The contraceptive pill can contain either a combination of both synthetic oestrogen and synthetic progesterone (known as progestogen) or progestogen-only. Studies have shown that taking combined oral contraceptives (oestrogen and progestogen) slightly increases breast cancer risk.  The risk reduces when you stop taking the pill and is no longer evident after around 10 years (from when usage stopped).

    Some studies suggest contraceptive pills containing progestogen-only may not be associated with breast cancer risk, while a more recent 2023 study has shown a very slight increase. More studies are needed to confirm this.

    Other types of hormonal contraceptives include injections and hormone-releasing intrauterine systems (e.g., Mirena coil), which contain progestogen, and patches and vaginal rings, which use both oestrogen and progestogen. There are fewer studies into the risks associated with these types of contraceptives, although the risks are thought to be similar to those associated with the contraceptive pill.

    Q7. Why are high levels of oestrogen potentially harmful?

    Higher levels of circulating oestrogens are associated with an increased risk of breast cancer (this is also true for men). Oestrogen encourages certain cell types, including breast cells, to divide more often. The more a cell divides, the more likely mutations will accumulate, which may lead to breast cancer. Oestrogen also encourages the growth of oestrogen receptor-positive breast cancers.

    Q8. Do transgender women have an increased risk of breast cancer?

    Several studies have shown transgender women (those assigned male sex at birth who identify as women) who undergo hormone treatment have an increased risk of breast cancer compared to cis men (who have not undergone treatment).

    However, transgender women are still at a lower risk of breast cancer compared to cis women who have not undergone hormone treatment. Transgender women who take hormone therapy may have a higher risk of breast cancer than the cis male population but a lower risk than the cis female population.

    For more information, see our resource for transgender people.

    Q9. Do transgender men have an increased risk of breast cancer?

    A Dutch study, based on a small sample size, found that transgender men (those assigned female sex at birth who identify as men) who undergo hormone treatment are at a lower risk of breast cancer compared to cis women (who have not undergone treatment) but at a higher risk than cis men.

    Many transgender men undergo a double mastectomy (breast tissue removal), which reduces breast cancer risk. Nonetheless, everyone is susceptible to breast cancer, and not all trans men undergo mastectomies, meaning they may remain at higher risk. Further studies are needed to assess the potential risks of long-term testosterone treatment.

    For more information, see our resource for transgender people.

  • Q1. Are there any ethnic groups in the UK more at risk of breast cancer?

    Some ethnic groups, including those with an Ashkenazi Jewish background, are more at risk than others. Some ethnic groups appear to have a lower risk. This may be due to genetics or lifestyle factors. 

    Individuals with an Ashkenazi Jewish background have a much higher risk of inheriting a BRCA gene mutation compared to other members of the UK population. Inheriting BRCA mutations increases breast cancer risk considerably. Please see Q2 in this section for more details about BRCA genes. 

    Studies have shown that some UK ethnic groups have lower breast cancer rates. Women from South Asian, black Caribbean and black African ethnic groups have a lower incidence compared to white women. One exception found in a recent analysis of population data in England is that young black Caribbean women (aged 25-49) have a similar breast cancer incidence rate to white women. 

    Differences in breast cancer rates between ethnic groups are thought to be due to differences in known reproductive and lifestyle factors for the disease. These factors include having more children at a younger age; breastfeeding; lower body mass index post-menopause; lower alcohol consumption and less use of hormone replacement therapy. Recent population data suggests some differences in cancer rates may also be due to differences in the average (median) age of populations. Indian, black African and Pakistani populations are younger on average than white populations and black Caribbean populations, and the risk of breast cancer for all people increases with age. 

    Despite a lower breast cancer incidence compared to white women, it is also true that black Caribbean, black African, Indian, Bangladeshi and Pakistani UK women are at greater risk of being diagnosed with breast cancer which is at a later stage, more aggressive and more difficult to treat. These differences are larger in older compared with younger women. The differences are also larger in black Caribbean and African ethnic groups than in the South Asian ethnic groups studied. Compared to white women, black African women are much more likely to be diagnosed with oestrogen receptor negative (ER-) breast cancer, which is harder to treat than ER+ breast cancer. They are also more likely to be diagnosed with HER2+ breast cancer, which can also be difficult to treat. 

    Read more on our ethnicity and breast cancer page.

    Q2. Does a family history of breast cancer put someone at a higher risk?

    Those who have inherited a specific gene mutation (e.g. a BRCA mutation) or with a strong family history of breast cancer (e.g. two first-degree relatives (mother, sister, or daughter) or one first-degree relative under 40 years who has had breast cancer) are at higher risk of getting the disease. For example having one first-degree relative (mother, sibling or daughter) who has developed breast cancer (especially at a young age) approximately doubles your risk. Having a BRCA mutation or a strong family history of breast cancer does not mean you will automatically get the disease; it means you are at higher risk. It should also be noted that most breast cancers occur in women who do not carry a single gene mutation or do not have a strong family history of the disease. Anyone can get breast cancer, although it is far more common in older women.

    Q3. What are BRCA1 and BRCA2 genes?

    BRCA1 and BRCA2 (BReast CAncer genes 1 and 2) are genes that produce proteins that help repair damaged DNA and help prevent cancer from developing.

    Women and men carry two alleles (versions) of these genes. People who inherit harmful variants (mutations) of either allele have an increased risk of several types of cancer, most notably breast and ovarian cancer in women and breast and prostate cancer in men. These mutations cause the protein to lose its function, so DNA repair is no longer functional. People with an inherited BRCA mutation also tend to develop cancer at a younger age. BRCA mutations can be inherited from either parent and each child of a parent carrying a BRCA mutation has a 1 in 2 chance of inheriting the mutation. 

    Q4. Is there a connection between breast cancer and ovarian cancer and are the causes the same?

    There is occasionally a strong connection between breast and ovarian cancer when either is due to a single inherited gene mutation, such as a mutation in a BRCA gene. This is known as “hereditary breast and ovarian cancer syndrome”. If either cancer is hereditary, then your risk is significantly increased for both cancers.

    If your cancer is not hereditary (e.g., not due to a single inherited mutation), then there is a loose connection based on both cancers sharing several common risk factors.

    Q5. Why are taller women at a higher risk of getting breast cancer?

    A study that included 5 million women found that being tall is a risk factor for hormone-responsive breast cancer. The reasons for this are not well understood, although it’s likely that genetic factors and biological pathways which affect adult height may explain the association. For example, taller women have higher levels of insulin-like growth factor-1 (IGF-1), which also promotes cell division and inhibits programmed cell death (increasing cancer risk). Cancer incidence increases with increasing adult height for most types of cancers.

  • Q1. Does having larger breasts increase the risk of breast cancer? 

    Research so far is inconclusive. Some early studies indicate having large breasts increases breast cancer risk, but others suggest no link is present.  

    What is more important is your breast density (see question 4 for more information). Moreover, the definition of a large breast in terms of size has not yet been clarified. 

    Q2. Am I more at risk of breast cancer if I have breast implants?

    There is no convincing scientific evidence to show implants increase breast cancer risk. However, breast implants may make breast cancer harder to detect. Importantly, you should always tell the radiographer that you have breast implants when you attend your screening appointment.

    There is also no evidence that breast reconstruction after cancer treatment carries an increased risk of breast cancer recurrence, whether or not implants are involved. Certain types of “textured” breast implants (no longer available in the EU or UK) slightly increase the risk of a rare type of lymphoma.

    Q3. Is stress a risk factor for breast cancer?

    So far, there is limited evidence of a direct link between stress and breast cancer risk, with much of the research producing conflicting results. Some studies have shown stress/psychological factors to increase breast cancer risk. Meanwhile, others have shown no association.  

    However, during stressful periods, it can be difficult for some people to maintain a healthy lifestyle, including maintaining a healthy weight, reducing alcohol intake and eating healthily. These factors have all been linked to a reduced cancer risk. Therefore, stress may indirectly increase the risk of cancer through influencing these other lifestyle factors. However more research is needed.  

    Q4. What does it mean to have dense breasts – is this a risk?

    High breast (or mammographic) density is a significant risk factor for breast cancer. Breasts are described as “dense” if they have lots of fibrous or glandular tissue and not much fat tissue. The density of breast tissue can only be detected on a mammogram and is not related to the size of your breasts or how they feel. Breast cancers can be more difficult to detect on a mammogram taken from a woman with dense breasts.  

    You cannot change your breast density directly, although it does change over time, and breasts tend to become less dense with age. 

    Q5. Does fluoride in drinking water increase breast cancer risk?

    There is insufficient evidence to conclude that fluoride in drinking water increases breast cancer risk.  Fluoride is a substance added to drinking water to prevent tooth decay.

    Q6. Does chlorine in drinking water increase breast cancer risk?

    There is insufficient evidence to conclude that chlorine in drinking water increases breast cancer risk, although some studies claim it could. 

    Chlorine is added to water as a disinfectant, and it is the byproducts that are produced during the chlorine disinfection process that some studies have linked to an increased risk of some cancers. However significantly more research is needed. 

    Q7. Can mammograms increase the risk of breast cancer?

    Mammograms deliver very low levels of ionising radiation, which may very slightly increase breast cancer risk. 

    According to NHS England, if a woman attends all seven screening examinations between the age of 50 up to her 71st birthday, the risk of radiation-induced cancer is between 1 in 7,000 to 1 in 14,000. 

    They also estimate that about 400 to 800 cancers are detected by the NHS mammography screening programme for every cancer that is radiation associated, meaning the risk of developing cancer outweighs the small risk incurred by having the mammogram.

    Q8. Does socioeconomic status affect your risk of breast cancer?

    Women who live in higher income areas have an increased risk of breast cancer compared to those who live in more disadvantaged areas. The reasons may be associated with reproductive and hormonal factors, such as later age at first childbirth, having fewer children and less breastfeeding, and certain lifestyle factors. 

    However, women in lower income areas often face later diagnosis which attributed to lower screening uptake and general awareness of breast cancer which affects survival outcomes.  

    Q9. Does where you live affect your risk of breast cancer?

    Women who live in wealthier countries have an increased risk of breast cancer compared to those who live in poorer countries. The reasons may be associated with reproductive factors, such as earlier age at menarche (first period), later age at first childbirth, having fewer children, less breastfeeding, and lifestyle factors such as increased obesity, alcohol consumption, and reduced physical activity.

    Living in urban areas, as opposed to rural areas, is also associated with increased risk. The reasons for this may be due to environmental factors such as increased pollution levels in urban areas or reproductive and lifestyle factors.

    Q10. Do underwire bras increase my risk of breast cancer?

    Underwire bras do not increase your risk of breast cancer.

    The claim is based on a suggestion that underwire bras block the drainage of lymph fluid from the bottom of the breast so it can’t get back into your body, but there is no reliable scientific evidence to support this claim.

    Q11. Does night shift work increase breast cancer risk?

    It is unclear whether night shift work may increase breast cancer risk.

    In 2019, the International Agency for Research on Cancer (IARC) classified night shift work as “probably carcinogenic to humans” and stated there was limited evidence that night shift work causes breast cancer. Since then, numerous epidemiological studies and meta-studies have been published on this subject with mixed results.  

    A suggested reason for an increased breast cancer risk in night-shift workers is that they have lower levels of the hormone melatonin, which plays a central role in regulating the body’s sleep cycle or circadian rhythm. Melatonin production peaks at night and is lower during the day. Light at night inhibits the release of this hormone into the bloodstream.  

    Melatonin is known to be protective against breast cancer. It reduces the growth and spread of breast cancer cells and, and it is anti-oestrogenic. 

    Any possible link between night-shift work and breast cancer risk is thought to be due to long-term night shift work (>20/30 years). 

    Q12. Does mobile phone use increase breast cancer risk? 

    Studies looking at mobile phone use over long periods of time have shown no evidence of an increased breast cancer risk.

    Additionally, there is no convincing evidence that storing mobile phones in bras increases breast cancer risk, as only a few very small studies have looked into this. 

    Research is still ongoing to ensure effects on cancer risk in the long-term, but none have been identified so far. 

    Q13. Does having type 2 diabetes increase breast cancer risk? 

    Breast cancer incidence has previously been shown to be higher in women who have type 2 diabetes compared to those who don’t. This is also particularly true for postmenopausal women. The reasons behind this increase are still not completely understood. Still, scientists believe there could be both direct (e.g., specific changes to the body in people with type 2 diabetes may be affecting risk) and indirect (e.g., being overweight, which is a risk factor for both diseases) causes.

 

Last review: Apr-26 | Next review: Apr-27.

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