Updated on April 10, 2024.
Breast cancer is the most common form of cancer among women, excluding skin cancers, affecting one in eight women at some point in their lives. In 2017, the American Cancer Society (ACS) estimated more than 316,000 women in the US were diagnosed with breast cancer, and more than 40,000 died from the disease.
Breast cancer is a disease in which breast cells grow irregularly and out of control, most often in the glands that produce milk or the ducts that carry milk to the nipple. To best protect yourself, learn the signs, symptoms and risk factors of breast cancer, and get prompt care if anything looks—or feels—unusual.
Risk factors for breast cancer
A risk factor is something that is associated with increased risk for a medical condition. Risk factors for breast cancer include a combination of genetic and lifestyle factors, including:
- Age—older than 50
- Genetic mutations—breast cancer 1 gene (BRCA1) and breast cancer 2 gene (BRCA2)
- Family history—parent, sibling, child or multiple relatives with the disease
- Onset of menstrual periods before the age of 12
- Dense breast tissue
Having these risks does not mean breast cancer is inevitable. Many people with known risk factors may never develop breast cancer, while some people with no risk factors get the diagnosis, according to the ACS.
Still, some risk factors may be under your control, like alcohol intake, weight, physical activity and cigarette smoking. “There's actually pretty good data that shows a link between smoking and increased breast cancer risk,” says Alene Wright, MD, a general surgeon with the Medical Center of Trinity in Trinity, Florida.
There's also reasonable data, according to Wright, that postmenopausal obesity—a body mass index above 29.9 after menopause (not having menstrual cycles for 12 months in a row)—can increase your breast cancer risk. Why? Levels of the hormone estrogen in people who are overweight or obese are higher. Body mass index, or BMI, is an estimate of body fatness based on weight and height, A BMI of 30.0 is considered obese, while a BMI of 25.0 to less than 30.0 is considered overweight.
“Fat cells increase estrogen in low levels even when your ovaries aren’t working anymore,” says Dr. Wright. “Many breast cancers are stimulated by estrogen.”
Because of the wide variability in who does—and doesn’t—develop breast cancer, it's important to know the signs and tell your healthcare provider (HCP) about any changes.
Signs of breast cancer you shouldn’t ignore
“I think the most important thing for women to know is sometimes there are no signs of breast cancer," Wright says. Instead, lumps or changes are found on routine screening.
Some people do experience symptoms, like a breast lump that lasts longer than one menstrual cycle, a change in color or thickness of the skin on the breast or pain in any area of the breast.
See your HCP if you notice changes like:
- Nipple discharge when not breastfedding; discharge could include blood
- Flaky skin or redness, especially around the nipple
- Change in the size or shape of one breast
- Dimpling of breast skin
- Pulling in of the nipple
If you notice any changes between visits to your HCP, discuss them with your HCP right away, even if you were screened recently. Even though changes may not turn out to be cancer, your HCP can best evaluate and determine whether further evaluation is needed.
In addition to reporting any changes in your breasts, it's important to go to routine screenings. Regular mammograms (which use low-dose X-rays to screen for early breast cancer) can help detect cancer before symptoms appear. Early detection allows for easier treatment and a better chances of recovery.
Beast cancer screening schedules
Different institutions have varying recommendations on when to start getting mammograms.
- The U.S. Preventive Services Task Force recommends women at average risk get screened every two years from ages 50 to 74, leaving it to someone's discretion, along with the advice of their HCP, about whether to start screening in their 40s. Women at higher risk may benefit from screenings in their 40s, the task force suggests.
- The ACS recommends women at average risk get annual screenings starting at age 45, or 40 if they prefer, and continue annual or switching to mammograms every two years at age 55. Women with certain risk factors—like a parent or sibling relative with a BRCA 1 or BRCA2 gene mutation—should have an MRI (magnetic resonance imaging, which uses radio waves to take images of the body) and mammogram annually starting at age 30.
Women should get screened as long as they're in good health and expected to live at least 10 years, the ACS recommends.
Since recommendations vary, it’s crucial to speak with your HCP about the best screening schedule for you. Wright believes that earlier screenings are beneficial to her patients. “I would recommend that a woman with average risk—meaning no strong family history, no prior history of breast concerns or breast biopsies—start at age 40 and have a mammogram once a year,” she says.
Forty is typically the age at which menopause is nearing, says Wright. “And we know that breast cancers tend to be more common in women who are menopausal.”
The important points are to stay up-to-date on your screenings and tell your HCP about a change in breast size, color or appearance as soon as you notice it. A prompt in-office evaluation can be pivotal to getting early treatment, or relieving your concerns.
