It’s natural for women to worry about breast cancer, especially since many people know someone who was touched by the disease. While there is no foolproof way to prevent breast cancer, there are things you can do to lower your risk. Some factors you can’t change, but knowing what can help is key to lowering your risk of breast cancer.
Breast cancer is the second most common cancer among women in the United States. Between 1989 and 2022, breast cancer death rates decreased by 44%, but racial and ethnic inequities still exist. While breast cancer incidence is lower among Black women than white women, the death rate is 38% higher among Black women than white women, according to the American Cancer Society.
That is because about one in five Black women with breast cancer have triple-negative breast cancer—more than any other racial or ethnic group. This is a complex area of ongoing study with various factors, including biologic, genetic and access to care. Meanwhile, Asian American and Pacific Islanders have the lowest death rate from breast cancer while Native Americans and Alaska Natives have the lowest rates of developing breast cancer. And while rare, men can get breast cancer too.
The AMA’s What Doctors Wish Patients Knew™ series gives physicians a platform to share what they want patients to understand about today’s health care headlines and how to take charge of their health through preventive care.
In this installment, two physicians shared what doctors wish patients knew about breast-cancer prevention. They are:
- Bonni Guerin, MD, a medical oncologist in Summit, New Jersey, at Atlantic Health and director of the breast services at Overlook Medical Center.
- Jill Jin, MD, an internist in Chicago and senior physician adviser for professional satisfaction and practice sustainability at the AMA.
Atlantic Health is part of the AMA Health System Member Program, which provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.
It is an uncontrolled growth
“Breast cancer occurs when abnormal cells in one or both breasts grow uncontrollably,” said Dr. Guerin. “While all cancers involve uncontrolled, unregulated cell growth, the type of breast cancer is determined by the specific kind of cells in the breast that are affected.”
Additionally, “breast cancers are also classified by certain types of proteins or genes each cancer might make,” she said.
The cause of breast cancer is unknown
“There are a multitude of risk factors for breast cancer, some of which that are beyond our control,” said Dr. Guerin. “For example, the female sex, age and genetics are not modifiable.
“However, risks that are modifiable include high BMI, alcohol intake and smoking,” she added.
Know the risk factors
“While risk factors for breast cancer are broad, we think primarily about age—around the age of menopause and after menopause is when breast cancer risk goes up in women,” said Dr. Jin. “Family history, of course, is another big one. That includes genetic mutations that we know of such as BRCA1 and BRCA2.”
“There’s also this whole concept of estrogen exposure, which can be both endogenous—within the body or how much your body produces—versus exogenous, from medications” she said. “Then other things like alcohol and smoking are thought to be associated somewhat with breast cancer as well.”
It's important to check your father’s side too
“People often think that breast cancer travels along the mother’s side, so their family history on their father’s side doesn’t matter,” said Dr. Guerin. “The truth is each side contributes equally. I think we often ignore the father’s side because we don’t see breast cancer in men very often, but men can carry the gene just the same.
“Additionally, we often think of our parents and siblings. But our risk of carrying the gene is affected by our second- and third-degree relatives,” she added. “I would like women to know that the cancers of their aunts, uncles, cousins and grandparents all affect our risk.”
“One needs to be an active investigator to find out if someone in your family had breast cancer or any cancer, but it’s important to find out,” Dr. Guerin said. “When I take a family history to look for patients who might carry a gene that puts them at risk for breast cancer, we go out to third-degree relatives.”
Start screening at age 40
“The current recommended age to start screening for breast cancer in average-risk women is 40,” said Dr. Jin. “However, if they do have a family history of early breast cancer in a first degree relative, or other risk factors, we may want to start screening earlier. It’s very individualized at the end of the day.”
Noting that screening recommendations vary by accrediting body, Dr Guerin emphasized “that women beginning at 40 years old should start yearly screening mammograms.”
Different screening tests are available
“There are several different screening modalities,” said Dr. Jin, noting that “a mammogram is the most common one. Other methods of screening include ultrasounds, as well as breast magnetic resonance imaging.”
“But for most people, we start with mammograms,” she said.
Screening tests are not perfect
“Screening at 40 instead of 50 saves more lives, but one caveat is that the younger people are, the more you pick up things that are not cancer, which is called a ‘false positive’ finding,” Dr. Jin said. “Younger women have denser breast tissue, and when breast tissue is dense, it is very hard to differentiate normal tissue from something that may look like cancer.”
“It is not uncommon to need to perform follow-up testing which includes additional mammograms and sometimes biopsy, after an abnormality is picked up on a screening mammogram, only to have everything turn out normal in the end,” she said. “I always counsel my younger patients, especially those getting their first mammograms, that it is common to see false positives or be called back for additional images, and there is no need to panic if that is the case because the chances are still that everything will turn out fine.
“Otherwise, the anxiety following an abnormal screening mammogram is huge, and can upend these women’s lives for weeks or even months, which is no small deal when they all have busy lives with families, kids and jobs,” Dr. Jin added.
Maintain a healthy lifestyle
“For all women—really for everyone—it is important to maintain a healthy lifestyle,” said Dr. Jin. That means “eating a balanced diet, not drinking too much alcohol, not smoking, maintaining regular physical activity and a normal body mass index.
“All of those things are likely helpful for prevention of not just breast cancer, but other cancers as well, along with cardiovascular disease—a lot of things,” she added.
Quit smoking to lower your risk
“When we think about risk factors of breast cancer, we think about them in two categories—modifiable and nonmodifiable risk factors,” said Dr. Guerin. “The modifiable risk category includes smoking.”
“Patients often think of smoking and lung cancer. But in truth, smoking also is linked to higher rates of other kinds of cancer, including breast, pancreatic, cervical and esophageal cancer,” she said. “So, smoking cessation is a goal that will reduce one’s risk of breast cancer and a long list of other cancers.”
Limit alcohol consumption
“Alcohol is challenging because it’s embedded in so much of our culture,” Dr. Guerin said. “Most recent data would support that there’s an increased risk of breast cancer with even one drink a day.
“While abstinence would be ideal, it’s important to meet patients where they are,” she added. “And for many patients, moderation is a more realistic goal.”
There are medications to reduce risk
“Chemoprevention, or the use of medications, is another option to reduce breast-cancer risk,” said Dr. Jin. “For chemoprevention, there are two classes of medications that are used. One is called selective estrogen receptor modulators, or SERMs.
“Tamoxifen is probably the most common one that is used. SERMs medications block the effects of estrogen in the breast,” she added. “Another class is called aromatase inhibitors. Those are usually used in older women after menopause and stop other hormones in the body from becoming estrogen.”
“However, both have other side effects. While tamoxifen blocks the effects of estrogen in breast tissue, it can actually enhance estrogen effects in other parts of the body, so we do worry about blood clots as well as uterine cancer,” said Dr. Jin. “And then aromatase inhibitors can cause other side effects related to low estrogen such as hot flashes, bone pain, decreased bone density, and increased risk of osteoporosis and fractures.”
“That’s why we don’t use these medications in everyone to decrease breast cancer risk, and reserve them for high-risk women only. Again, as with every decision in medicine, we want to make sure the balance of potential benefits versus harms is in favor of benefits,” she said.
Surgical prevention is also an option
“The other kind of prevention would be surgical prevention,” said Dr. Jin. “This is also done for women who are high risk, most commonly because of the BRCA gene mutation.”
“People who have a known BRCA gene mutation, which puts them at an increased risk for both breast and ovarian cancer, are candidates for surgery to remove the breasts. That’s called prophylactic mastectomy,” she said. “They also may be candidates for surgery to remove the fallopian tubes or ovaries to decrease the risk of ovarian cancer as well.”
Test for the BRCA gene mutation
“There are calculators that can be used to calculate whether someone, based on their family history and ethnicity, should get genetic testing for the BRCA gene mutation, which is a blood test” said Dr. Jin. “If you have a first-degree family member—such as your mom or sibling—who has breast cancer and is known to have BRCA, then you should get tested for it.
“If you just have a family history of breast cancer with unknown BRCA status, that’s when the calculators come into play,” she added, noting “they look at how many first-degree and second-degree relatives, whether you are of Ashkenazi Jewish descent, and certain other risk factors to decide whether you should get the genetic testing.”
Breastfeeding may reduce risk
While there are no clinical trials on this topic, “there is observational data that does suggest that breastfeeding is protective against breast cancer,” said Dr. Jin. The same goes for “having children versus not having children; pregnancy does seem to be protective as well.
“We’re not saying go get pregnant and breastfeed to reduce your risk of having breast cancer—it’s not practical,” she added. “But it does seem to be an association.”
Birth control is OK to take
This is also “somewhat controversial, but overall, the link between birth control and breast cancer is very small to none,” Dr. Jin said. “When I talk with my patients about this, I share that using birth-control pills most likely does not increase the risk of breast cancer in a clinically significant way.
“Furthermore, this very small potential increase in risk is limited to the time that you’re actually taking birth-control pills,” she said. “So, it’s not a permanent effect. It’s temporary.”
Additionally, “birth control pills are protective against some other cancers such as uterus cancer or ovarian cancer,” said Dr. Guerin. “Birth control pills also protect against unwanted pregnancies, which is important as well.”
“Birth-control pills are a reasonable option, but it needs to be a balanced discussion of risks and benefits with your primary care doctor,” she said.
Be cautious with self-breast exams
“There has not been any good evidence to show that self-screening has any overall benefit in mortality,” said Dr. Jin. “Breasts are just lumpy to begin with, and a lot of people end up feeling “lumps” that just end up being normal breast tissue.
“And you may end up, again, going down that path of all the imaging and the biopsies and in the end, it is nothing,” she added. “So, self exams are not recommended by clinical guidelines.”
“However, some people are going to be wanting to do that anyways and that is fine. If someone really wants to stay on top of their body, I will explain that breasts can feel lumpy or bumpy, and what they are looking for is a change from baseline. At the end of the day, you still know your own breasts and your own body the best,” said Dr. Jin. “So, if you feel something that is different, that you have not felt before, then you should let me know and we can decide at that point what to do,”
“If they are in the office with me, I am happy to do a quick exam of the breast and tell them this is what your normal breast tissue feels like, don’t be alarmed if you feel this or if you feel this. It is just normal.”
Don’t hesitate to talk to your doctor
“While screening is recommended at age 40,” said Dr. Jin, “if at any point you do notice something like a lump or you see something weird on the skin or if you have pain or any symptoms that are different than normal, that takes you out of the typical asymptomatic screening category.”
“As with all cancer screening, when a symptom is detected that is different, you should never hesitate to bring that up to your doctor,” she emphasized.
Advocate for other women too
“Women under 40 represent a group with a concerning increase in incidence of breast cancer,” said Dr. Guerin. “To reach women under 40 who are not recommended annual screening mammograms, there is an opportunity to connect with your friends, family, co-workers and ask if they are addressing their modifiable risk factors, and investigating their family health history.
“This is an opportunity for us to be each other’s caregivers,” she added.
