The short answer: many widely believed claims about breast cancer are not supported by scientific evidence. Wearing a bra, using deodorant, experiencing stress, or having a physical injury to the breast do not cause breast cancer [3][4][5][6]. Breast cancer is not always fatal, it does not always require removing the whole breast, and men can get it too [1][7][13]. The real risk factors are well documented: age, genetics, alcohol use, obesity, and reproductive history. Misinformation matters because it can distract from evidence-based prevention and delay diagnosis [2][8].
Breast cancer is the most commonly diagnosed cancer among women worldwide. Yet public understanding of what causes it remains poor in many countries. A 2025 study in Saudi Arabia found that only 13.2 percent of women surveyed could correctly identify ten or more breast cancer myths [2]. A 2023 study in Palestine found similar results, with very few women recognizing common misconceptions [8].
This article separates the myths from the documented facts.
Myth: Wearing a bra causes breast cancer
Documented evidence: False.
There is no reliable scientific evidence linking bra wearing, including underwire bras, to breast cancer [9][15]. A study by the Fred Hutchinson Cancer Research Center interviewed over 1,000 women with breast cancer and 500 without. It found no difference in bra use between the two groups [15]. An earlier Harvard study of over 15,000 women reached the same conclusion [15].
The claim likely arose from the idea that bras restrict lymph flow and trap toxins. The Canadian Cancer Society states clearly that there is no reliable scientific evidence for this [9]. The Cleveland Clinic also confirms that there is no evidence that wearing a bra while sleeping increases breast cancer risk [3].
Myth: Deodorant and antiperspirant cause breast cancer
Documented evidence: False.
Concerns about aluminium salts in deodorants have circulated for years. France’s National Cancer Institute reviewed the evidence and concluded that no study has confirmed a causal link between antiperspirant use and breast cancer [4]. The Royal Marsden NHS Foundation Trust states that deodorants are considered safe and that aluminium has not been found to have oestrogen-like effects or cause breast cancer [10].
The American Cancer Society notes that the studies linking antiperspirants to breast cancer are limited to case-control studies with mixed results. It also explains that only a tiny fraction of aluminium is absorbed through the skin, far less than what is consumed in food [16].
Why do people avoid deodorant before mammograms? Because aluminium can appear as white spots on the images and complicate assessment. It is a technical issue, not a safety one [10][16].
Myth: Stress causes breast cancer
Documented evidence: No consistent link.
Cancer Research UK states that stress does not directly cause cancer. A large study of over 100,000 women in the UK found no link between stress and breast cancer risk. A large European study of over 100,000 people found no evidence of a link between stress and common cancers [5].
Stress can indirectly affect cancer risk by making it harder to maintain healthy habits. People who are stressed may sleep poorly, eat unhealthy food, drink more alcohol, or smoke. These behaviours, not stress itself, can affect risk [5].
A 2024 review in Cancer Causes & Control noted that while patients often cite stress as a cause, the epidemiological evidence is conflicting. The authors suggest that stress reduction interventions may still improve outcomes for patients, but this is about supporting well-being, not preventing the disease [11].
Myth: A physical injury to the breast causes cancer
Documented evidence: False.
Cancer Research UK states clearly that physical trauma or injury to the breast does not cause cancer. Cancer happens when DNA in cells is damaged, causing uncontrolled division. There is no research showing that breast injury can cause DNA damage that leads to cancer [6].
Sometimes an injury leads to a lump, but this is usually bruising, swelling, or scar tissue called fat necrosis. These lumps are not cancer and do not increase cancer risk [6]. The Canadian Cancer Society notes that an injury may lead to finding a cancer that was already there, but the injury did not cause it [12].
Myth: Breast cancer is always fatal
Documented evidence: False.
Survival depends heavily on the stage at diagnosis and the aggressiveness of the cancer. In Germany, the relative ten-year survival rate is 83 percent for women and 68 percent for men [1]. When breast cancer is detected early and has not spread, the five-year relative survival rate is 99 percent [18].
Breast cancer is a serious disease, but it is not an automatic death sentence.
Myth: Only women get breast cancer
Documented evidence: False.
Men can and do get breast cancer. Approximately 1 in 735 men will develop it [13]. While it is about 100 times more common in women, men should also be aware of changes in their breast tissue [18]. The most common sign in men is a hard lump under the nipple and areola [1].
Myth: If you have no family history, you are not at risk
Documented evidence: False.
Only 5 to 10 percent of women who get breast cancer have a family history. That means 90 to 95 percent do not [13]. The average risk for a woman is about 1 in 8, and most of these women have no family history [13].
A 2026 study from Cedars-Sinai found that women who tested negative for BRCA mutations but had a family history still had a 25 percent lifetime risk of developing breast cancer [2].
Myth: Breast cancer always requires removing the whole breast
Documented evidence: False.
Breast-conserving surgery (lumpectomy) followed by radiation is often as effective as mastectomy for many patients. Studies show that overall survival is the same for both approaches [7]. Doctors generally recommend breast-conserving surgery when it is medically appropriate, to reduce the psychological burden of losing a breast [7].
What actually increases breast cancer risk
The documented risk factors include:
- Age. The risk increases with age, and most cases occur in women over 50 [18]
- Genetics. BRCA1, BRCA2, and other genes including PALB2, ATM, and CHEK2 increase risk [2]
- Alcohol consumption. Risk increases with the amount consumed. Women who have one drink per day have a 7 to 10 percent increase; those who have 2 to 3 drinks per day have about a 20 percent increase [15]
- Obesity after menopause. Excess fat raises estrogen levels [15]
- Reproductive history. Starting periods early, starting menopause late, having a first child after 30, or never having children [18]
- Hormone therapy. Combined estrogen and progesterone use after menopause [18]
- Dense breast tissue. Having more glandular tissue and less fat [1]
- Radiation exposure to the chest at a young age [18]
The bottom line
Many common beliefs about breast cancer are myths. Bras, deodorants, stress, and injuries do not cause the disease. Breast cancer is not always fatal, does not always require mastectomy, and affects men as well as women. The documented risk factors are age, genetics, alcohol, obesity, reproductive history, and certain medications. Distinguishing myths from facts matters because it helps people focus on what actually reduces risk and what actually saves lives: early detection and evidence-based treatment [2][8].
Disclaimer
This article is for informational purposes only and is not a substitute for professional medical advice. If you have concerns about breast cancer risk or symptoms, consult a qualified healthcare provider. We welcome your feedback and corrections. Please contact us if you notice any errors.
References
[1] 8 Brustkrebs-Mythen und die Fakten, Novartis. https://www.novartis.com/de-de/node/281161/printable/pdf
[2] Myths and Misconceptions of Breast Cancer Causation among Female Population of Saudi Arabia, PubMed. https://pubmed.ncbi.nlm.nih.gov/40542778/
[3] Is It Bad To Sleep in a Bra?, Cleveland Clinic. https://health.clevelandclinic.org/sleeping-in-a-bra
[4] Les sels d’aluminium dans les déodorants favorisent-ils les cancers du sein ?, Institut national du cancer. https://leseclairages.cancer.fr/les-sels-daluminium-dans-les-deodorants-favorisent-ils-les-cancers-du-sein/
[5] Does stress cause cancer?, Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/cancer-myths-questions/can-stress-cause-cancer
[6] Does breast injury or trauma cause cancer?, Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/cancer-myths-questions/does-breast-injury-trauma-cause-cancer
[7] 乳腺癌——那些你不得不防的认知误区, 央广网. https://health.cnr.cn/jkgdxw/20250317/t20250317_527103291.shtml
[8] Common myths and misconceptions about breast cancer causation among Palestinian women, National Institutes of Health. https://pmc.ncbi.nlm.nih.gov/articles/PMC10688078/
[9] Does wearing a bra increase my risk of breast cancer?, Canadian Cancer Society. https://cdn.cancer.ca/en/cancer-information/reduce-your-risk/myths-and-controversies/does-wearing-a-bra-increase-my-risk-of-breast-cancer
[10] Busting breast cancer myths, The Royal Marsden. https://www.royalmarsden.nhs.uk/private-care/news-and-blogs/busting-breast-cancer-myths
[11] Mechanisms of stress-attributed breast cancer incidence and progression, Institut national du cancer. https://www.e-cancer.fr/Professionnels-de-la-recherche/Veille-bibliographique/Nota-Bene-Cancer/Nota-Bene-Cancer-612/Mechanisms-of-stress-attributed-breast-cancer-incidence-and-progression
[12] Can a physical blow or injury cause cancer?, Canadian Cancer Society. https://cancer.ca/en/cancer-information/reduce-your-risk/myths-and-controversies/can-a-physical-blow-or-injury-cause-cancer
[13] Understanding breast cancer – Screening, treatment and advocacy, VCU Massey Comprehensive Cancer Center. https://www.masseycancercenter.org/news/understanding-breast-cancer—screening-treatment-and-advocacy/
[14] Common myths and misconceptions about breast cancer causation among Palestinian women, 국립의과학지식센터. https://library.nih.go.kr/ncmiklib/search/Retrieve.do?dbid=edssjs&an=edssjs.9558C14F
[15] CLAIM: Wearing bras can cause breast cancer, Cancer FactFinder. https://cancerfactfinder.org/fact-finder-tool/bras/
[16] Antiperspirants and Breast Cancer Risk, American Cancer Society. https://www.cancer.org/cancer/risk-prevention/chemicals/antiperspirants-and-breast-cancer-risk.html
[17] Incidental finding of a mucinous carcinoma of the breast by dynamic MRI in a patient with a history of breast trauma, PubMed. https://pubmed.ncbi.nlm.nih.gov/12140155/
[18] Why it’s so important to get regular breast cancer screenings, UC Davis Health. https://health.ucdavis.edu/blog/cultivating-health/why-its-so-important-to-get-regular-breast-cancer-screenings/2022/10
[19] Does a bite cause cancer? Misperceptions of breast cancer etiology among low-income urban women in Miami, Florida, PubMed. https://pubmed.ncbi.nlm.nih.gov/24305520/
