Proactive steps for breast cancer risk reduction: Part 3

Part 3: Proactive steps for breast cancer risk reduction: How can I help reduce my breast cancer risk?

We don’t want to over simplify breast cancer risk. Some women develop breast cancer, and doctors don’t know why. But there are some lifestyle habits that can reduce your risk of developing or dying from breast cancer. Doctors learned about these risks by studying thousands of women with and without breast cancer, and comparing their lifestyle habits.

An active lifestyle is easier said than done. But moving your body is important for your health, and being active can reduce your risk of developing and dying from cancer.¹ You don’t have to be a fitness guru. It can be as simple as walking around the block, climbing the stairs instead of taking the elevator, parking at the back of the parking lot, or getting off the bus/train one stop earlier and walking the rest of the way. 

Consider the external hormones that you are taking.

Oral Contraceptives and hormone replacement therapies are important medications for millions of women. They are not bad. In fact, they are known to decrease the risk of some diseases like heart disease, colorectal cancer and endometrial cancer. But they are also linked to a small increase in risk of breast cancer. This is a conundrum. Talk to your doctor about your risks for all these diseases...it’s a balance of your own risk factors and no two people are alike. What may work for one woman, may not work for another.

We are programmed to sleep and wake at certain times; this is called your Circadian rhythm. When your internal clock is messed 

up it can increase your risk for disease. Some of us may not have control over our job schedule, a nightshift may be inevitable, or jet lag may be a constant part of your life. But there are some simple fixes to try and keep a healthy and consistent sleep routine. If you are a nighttime phone-reader—try not to bring your phone/tablet to bed. The bright light of the screen can make it harder to fall asleep. Exercise during the day can make it easier to fall asleep at night. Try not to eat a heavy meal right before bed, you might not sleep as well.²

Breastfeeding can influence your breast cancer risk. For those who have been there, we all know how difficult breastfeeding can be, from latching problems, to clogged ducts, to pumping in inconvenient and questionable locations. But if you do have the option, the ability, and the support to do it, every 12 months of breastfeeding reduces your risk of developing breast cancer. We will talk about some of the potential biological reasons for this in a later article! 

Post Menopause your body is entering a new phase. You have hopefully been able to work through all the side effects that you feel from your body making some significant hormonal changes. This is the time women are at highest risk of breast cancer. Maintaining your mammogram screening, your breast awareness and keeping a healthy weight will significantly reduce your risk of developing breast cancer.

Yes, there are risk reducing medications that women can take. This is not like taking a vitamin. These are serious drugs taken over five years that help block estrogen in your body (estrogen is one of the big drivers of breast cancer, but not the only driver!). Based on nearly 30 years of clinical trial data, we know these drugs can reduce a woman’s risk of developing breast cancer by up to 65%! But, there are side-effects to these drugs. A thoughtful discussion with a cancer prevention specialist can help you decide whether a preventative medication like this is worth the side-effects. There are a few different types of risk reducing medications, selective estrogen receptor modulators (SERM) and aromatase inhibitors (AI). Tamoxifen (a SERM) is the only option for pre-menopausal women. Post-menopausal women have more options including raloxifene (a SERM) or Anastrozole/ Exemestane (both AI). 

Only women at increased risk of breast cancer are eligible for these medications. Risk is measured by an assessment model to calculate a five-year risk score. If your risk is more than 3%, then you should definitely be having a conversation about the medication options available to you. (Risk assessment tools are discussed here in more detail). 

Every woman is different, and every breast cancer is different. Risk reducing medications discussed above are designed to target tumors that have estrogen receptors (that’s about 80% of all breast cancers). For the breast cancers without hormone receptors (like estrogen that we’ve been talking about), there is interesting research looking at the risk reducing ability of aspirin. A recent study showed a 30% risk reduction of hormone-receptor-negative breast cancer in women who used aspirin regularly compared to women who didn’t.³

No, this doesn’t mean you should just pick up some aspirin at the store…but it does mean you have the opportunity to talk about low dose aspirin with your doctor, particularly because we know it reduces risk of heart disease and colorectal cancer too. As always there is a flip side to taking the medication, low dose aspirin can also increase risk of bleeding in your stomach, intestine and brain.  

Finally, keep your routine mammogram appointments. Screening mammograms can’t reduce your risk of getting breast cancer, but they can reduce your risk of dying from breast cancer by 40%.⁴ 

We advocate for all women to start annual screening at 40. But If you are unsure of whether that is right for you, look at your risk factors (checklist) and discuss with your doctor so you better understand your risk and what screening options would best benefit you and your lifestyle.

1. University of Texas M. D. Anderson Cancer Center. (2020, June 18). Sedentary behavior independently predicts cancer mortality: Replacing sitting time with 30 minutes of activity associated with lower risk of cancer death. ScienceDaily. Retrieved January 6, 2021 from www.sciencedaily.com/releases/2020/06/200618150311.htm
2. Lin HH, Farkas ME. Altered Circadian Rhythms and Breast Cancer: From the Human to the Molecular Level. Front Endocrinol (Lausanne). 2018;9:219. Published 2018 May 4. doi:10.3389/fendo.2018.00219
3. Bertrand, K.A., Bethea, T.N., Gerlovin, H. et al. Aspirin use and risk of breast cancer in African American women. Breast Cancer Res 22, 96 (2020). https://doi.org/10.1186/s13058-020-01335-1
4. Seely JM, Alhassan T. Screening for breast cancer in 2018-what should we be doing today?. Curr Oncol. 2018;25(Suppl 1):S115-S124. doi:10.3747/co.25.3770