Breast cancer incidence is rising; in fact, rates have risen in most of the past four decades. From 2010 to 2019, the incidence has risen by 0.5 percent each year. On the other hand, breast cancer mortality has been dropping steadily (since peaking in 1989).

The breast cancer death rate dropped by nearly half (43 percent) from 1989 to 2020, according to findings published in CA: A Cancer Journal for Clinicians. Unfortunately, racial disparities persist.

This decline in breast cancer death rates is significant and may be attributed to earlier detection through awareness and screening plus management advances. While I welcome the improvements in breast cancer mortality, I want to focus on some key ways you may reduce your risk of being diagnosed with breast cancer.

Let’s get to the top ways to significantly reduce your chances of getting (or dying from) breast cancer.

1. Don’t smoke.

If you currently smoke cigarettes (and have for more than ten years), you have a higher risk of developing breast cancer. This finding is not particularly surprising, nor is the fact that the duration of smoking matters: Those smoking for 40 years have a 1.6-times greater risk of breast cancer than non-smokers.

Moreover, the number of years smoked before a first full-term pregnancy appeared to be associated with a higher risk of breast cancer than comparative years smoked after pregnancy. Cigarettes are linked to breast cancer development, and the timing of the smoking exposure matters.

Whether women who previously smoked have a higher risk of breast cancer remains under investigation.

2. Breastfeed

Breastfeeding is associated with slightly lower breast cancer risk, especially for those who opt to nurse for a year or more.

Breastfeeding is associated with only a modest risk reduction; a large pooled analysis that included individual data from 47 studies (including about 50,000 women with invasive breast cancer and 97,000 controls) estimated that for every year of breastfeeding, there appeared to be a 4.3 percent reduction in the relative risk of breast cancer. If your risk had been 15 percent, breastfeeding might drop by slightly less than one percent.

3. Postmenopausal weight loss

Some, but not all, studies show that weight loss in postmenopausal women may reduce breast cancer risk. For example, a meta-analysis that included 237,000 women with breast cancer (and four million controls) discovered weight loss associated with nearly one-fifth (18 percent) lower breast cancer risk.

The Nurse’s Health Study prospectively assessed weight change since menopause among approximately 50,000 women followed up to 24 years. Here are the results:

Women with no prior hormone therapy use who maintained a weight loss of at least 10 kilograms (22 pounds) had more than a halving of breast cancer risk than women who did not.

4. Child-bearing

A full-term pregnancy affects breast cancer, but this influence hinges upon the age of the first full-term birth. Women bearing children later in life have an increase in breast cancer risk.

The Nurses’ Health Study looked at women who never delivered a baby compared with child-bearing women. The cumulative incidence of breast cancer by age 70, compared with a woman bearing no children, was as follows:

• For women delivering a first child at age 20, the risk dropped by one-fifth (for a woman with a one in eight baseline risk in the USA or many parts of northern Europe, a decrease by about two to three percent).
• For women delivering a first child at age 25, the breast cancer risk dropped by one-tenth or just over one percent for a woman at average risk in the United States.
• For women delivering a first child at 35, the breast cancer risk rose by one-twentieth. This risk is comparable to a woman who never had a full-term pregnancy.

Breast cells fully differentiate during and after pregnancy, which may protect the breast from cancer. On the other hand, having a first birth at a later age may increase the risk by giving additional stimulation to breast cells that are more likely to develop (and more likely to be damaged).

5. Move

The available research suggests that physical activity is associated with a lower risk of breast cancer. A meta-analysis of 139 studies discovered:

Higher physical activity levels appeared to lower breast cancer risk by nearly one-quarter (a drop by 22 percent in relative risk). This risk reduction appeared similar in pre- and postmenopausal women and for high- versus light-intensity movement.

Because higher weight in premenopausal women is associated with a lower breast cancer risk (higher weight raises the risk in postmenopausal women), the drop in risk is not because of weight loss associated with physical activity.

Blood levels of hormones (such as estrogen), insulin, and insulin growth factor-1 (IGF-1) may impact risk.

6. Watch the alcohol

Alcohol consumption is associated with a higher risk of breast cancer driven by estrogen or progesterone hormones. For example, a study of nearly 52,000 postmenopausal Swedish women discovered this:

Increased alcohol intake appeared associated with estrogen receptor-positive breast cancer, with a 1.35-fold increase (if you have a baseline risk of 12 percent, it will rise by about four percent).

Could folic acid intake decrease the alcohol-associated increase in breast cancer risk? Observational studies hint that those who consume alcohol should take a multivitamin with folic acid, but our grain has supplemental folate in the USA.

7. Get appropriate screening

Women between the ages of 40 and 44 should consider beginning annual mammograms. Women ages 44 to 54 years should have annual screening, and those 55 and older have the option to test every one or two years. Breast cancers discovered by annual mammograms are usually smaller and less advanced than those discovered during mammograms every two years.

8. Get to know your genes

Modern medicine has made assessing one’s risk of developing various forms of cancer much simpler. This understanding of risk can be especially helpful for women with inherited gene mutations that make them particularly vulnerable to breast cancer. The American Cancer Society explains, “When it comes to breast cancer risk, the most important inherited gene changes are in the BRCA1 and BRCA2 genes. Women (and men) with one of these gene changes are said to have Hereditary Breast and Ovarian Cancer (HBOC) syndrome.”

9. Risk-reducing surgery or medicines

Some medicines may significantly reduce the chances of developing the disease for women with a higher-than-average breast cancer risk. Because risk-reducing drugs such as tamoxifen, raloxifene, or aromatase inhibitors have potential side effects, you will need to balance the pros and cons of the medicine.

This approach of using medicines to help reduce disease risk is chemoprevention. If you are considering this approach, first have a health care provider help determine your breast cancer risk.

The American Cancer Society explains that some important breast cancer risk factors include:

• Older age
• Having close relatives with a breast cancer history
• Having more menstrual cycles
• Having a history of invasive breast cancer or ductal carcinoma in situ (DCIS)
• A history of breast lobular carcinoma in situ (LCIS, atypical ductal hyperplasia (ADH), or atypical lobular hyperplasia (ALH)
• Having a gene mutation associated with a family cancer syndrome (such as a BRCA mutation)

10. Eat well

A limited number of studies suggest that there may be a connection between eating fruits and vegetables regularly and a lower risk of developing some aggressive forms of breast cancer.

I hope this article helps you understand how lifestyle influences breast cancer risk. Thank you for joining me today.