Breast Cancer Myths: Separating Fact from Fiction

By Ted Gansler, MD, MBA, MPH

You have probably seen and heard a lot about breast cancer during the past few weeks, but as we approach the end of this year’s breast cancer awareness month this is a good time to ask how much of the information you encountered is actually true. See if you know which of the following statements are true and which are false…

TRUE OR FALSE: Most breast cancer is hereditary. You don’t need to worry if you don’t have a family history of breast cancer.

FALSE. Only about 5% to 10% of breast cancer cases are thought to be the result of gene defects (called mutations) inherited from a parent. The lifetime risk for breast cancer can be as high as 80% for members of some families who inherit certain mutations of BRCA genes. The risk is not nearly as high for most women with a family history of breast cancer. On average, having 1 first-degree relative (mother, sister, or daughter) with breast cancer approximately doubles a woman’s risk, and having 2 first-degree relatives triples her risk. About 20% to 30% of women with breast cancer have a family member with this disease (although most of these families do not have abnormal BRCA genes). This means that most women (70% to 80%) who get breast cancer do not have a family history of this disease.
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TRUE OR FALSE: If you have a family history of breast cancer, there is nothing you can do to protect yourself from this disease.

FALSE. If 1 or more of your relatives have had breast cancer, be sure to tell your doctor. Careful discussion of which and how many relatives were affected can determine whether you may benefit from genetic counseling or even genetic testing. It is estimated that only a few percent of women who should consider breast cancer genetic testing actually get tested, and the main reason is that doctors and patients do not discuss this topic enough. If genetic tests show that you are at very high risk, doctors will recommend starting screening earlier, and using MRI scans as well as mammograms. Screening can find breast cancer earlier, when treatments are more likely to be successful. Additional options include medications and even surgery to help reduce your risk of developing breast cancer.
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TRUE OR FALSE: There is nothing a woman with average risk can do to reduce her risk of developing breast cancer.

FALSE.  Many breast cancer risk factors are things you cannot change, like your age, your family history, and how old you were when you started and stopped having menstrual periods. But there are other important breast cancer risk factors that you do have some control over, and which can help reduce your risk of developing breast cancer: your weight, your physical activity level, and how much alcohol you drink.

Weight: Being overweight or obese has been found to increase breast cancer risk, especially after menopause. Before menopause, your ovaries produce most of your estrogen, and fat tissue produces a small amount of estrogen. After menopause (when the ovaries stop making estrogen), most of a woman’s estrogen comes from fat tissue. So, having more fat tissue after menopause can increase your chance of getting breast cancer by raising estrogen levels. Achieving and maintaining a healthy weight throughout life is recommended to reduce your risk of breast cancer, several other forms of cancer, and heart disease and diabetes.

Physical activity: Many studies agree that being active decreases a woman’s risk of developing breast cancer. On average, highly active women are 25% less likely to develop breast cancer than are women who get very little activity. Although vigorous activity like jogging, fast bicycling, swimming, jumping rope, etc. for at least 45 to 60 minutes on most days is recommended, a lower level of activity can also help. One large study found that walking for even 75 to 150 minutes during the entire week reduced breast cancer risk by 18%.

Drinking alcohol: Compared to women who do not drink any alcohol, there is a 10% to 12% higher risk of breast cancer associated with each drink per day. Excessive alcohol use is also known to increase the risk of developing cancers of the mouth, throat, esophagus, and liver. The American Cancer Society recommends that women limit their consumption of alcohol to no more than one drink a day, if they drink at all.

Although medicines and even surgery are options to consider for women at increased risk, they are not recommended for women at average risk.

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TRUE OR FALSE: A breast injury can develop into breast cancer.

FALSE. There is no evidence that bruising your breast leads to cancer. The origin of this belief is probably that localized pain may draw attention (on the part of a woman or her doctor) to the area, thereby making it easier to notice a tumor that’s actually been there for some time.

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TRUE OR FALSE: Only women can get breast cancer.

FALSE. Men can develop breast cancer, too, but this disease is about 100 times more common among women than men. Each year breast cancer is diagnosed in about 230,000 women and 2,200 men, and each year about 40,000 women and 400 men die from breast cancer.¬† Many men think that only women can get breast cancer; this misunderstanding may cause some men to ignore breast lumps until the cancer has spread too far to be curable. Being a woman is the main risk factor for developing breast cancer. Women have many more breast cells than men, which increases the odds that some of these cells may become malignant. Also, a woman’s breast cells are exposed to the growth-promoting effects of the female hormones estrogen and progesterone, and this combination increases breast cancer risk.
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TRUE OR FALSE: Monthly self examination is the best way to find breast cancer early.

FALSE. The American Cancer Society no longer recommends that all women routinely perform monthly breast self-exams (BSE). Instead the Society emphasizes breast awareness, which means knowing how your breasts look and feel and being alert to any changes in your breasts that you may notice while showering, dressing, etc. Research has shown that breast awareness seems to be more effective for detecting breast cancer than a formal monthly BSE. When women find their own breast cancer it is usually while bathing, showering or dressing, and less often during a specific BSE. Women who still want to do monthly BSE in addition to being aware of breast changes throughout the month should ask their health care providers for instruction on how to do this exam most effectively.

Women who notice lumps or any other changes in their breasts should contact their doctor immediately¬† — even after a recent, normal mammogram. Although a woman’s awareness of changes in her breasts is important, having mammography done according to guidelines saves more lives, because mammograms can find many cancers that are far too small to be felt; it is these small cancers that are most likely to be curable.
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TRUE OR FALSE: Lumps are the only sign of breast cancer.

FALSE. Skin irritation or dimpling, nipple pain or retraction (turning inward), redness or scaliness of the nipple or breast skin, or a discharge other than breast milk can also be important warning signs for breast cancer. In one uncommon but aggressive form of breast cancer called inflammatory breast cancer, or IBC, women usually do not notice a lump, and the only symptoms may be redness and thickening of the skin covering the breast, sometimes together with swelling of the breast. It is important not to ignore these changes or assume they are the result of an infection. If you have breast changes like these, get checked by a doctor.
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TRUE OR FALSE: Mammography is perfect. OR Mammography is useless.

BOTH FALSE. On average, mammography will detect about 80%-90% of breast cancers in women without symptoms. There is some disagreement among doctors about how many lives are saved, when to start mammography, and how often to have it, but nearly all experts agree that mammography saves lives. ACS recommends annual mammography starting at age 40.
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TRUE OR FALSE: Antiperspirants are one of the most important causes of breast cancer.

FALSE. Some chain e-mails and websites have suggested that chemicals in underarm antiperspirants are absorbed through the skin, interfere with lymph circulation, cause toxins to build up in the breast, and eventually lead to breast cancer. There is very little scientific evidence to support any of these claims, and most of this research has been done only in the laboratory, not in people.

On the other hand, a large study comparing the underarm hygiene habits of women with breast cancer to a control group without breast cancer found no connection between breast cancer risk and using underarm antiperspirants and/or underarm shaving. Women who are not reassured by this study may still choose to avoid these products. However, while it is reasonable to be careful about some factors of unproven risk, it is even more important to take steps to avoid known risk factors (see above) whenever possible and to follow guidelines for early detection and high quality treatment.