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7 Surprising Factors That Affect Your Breast Cancer Risk

Posted in: Blogs , English

You’ve probably heard that an unhealthy diet or a family history of breast cancer can increase your risk of developing breast cancer. However, there are many more risk factors you might not have considered. Knowing risk factors gives you the power to make lifestyle changes to reduce your risk and make informed decisions regarding when to start screening.

1. Alcohol

Women who regularly consume alcohol (at least one drink a day) have an increased risk of breast cancer. Drinking alcohol can raise the levels of hormones in your body that have an impact on hormone-receptor-positive breast cancer.

2. Diethylstilbestrol (DES)

Diethylstilbestrol is a medication given to some pregnant women to prevent miscarriage between 1940 and 1971. Women who took this medicine and women whose mothers took DES while pregnant with them have a higher risk of breast cancer.

3. Dense Breasts

Dense breasts contain more fibrous and glandular tissue and less fat than average breasts. This tissue makes it harder for a mammogram to detect tumors, meaning a cancer could spread before you notice it. While dense breast tissue is common, this type of breast may be more prone to developing cancer.

4. Birth Control

Studies show a link between the use of oral contraceptives and progesterone injections and an increase in the risk of breast cancer in women. There aren’t enough studies on intrauterine devices (IUDs) to determine if their use also increases your chance of breast cancer. While a woman’s risk of breast cancer does increase somewhat while she’s on birth control, it will return to that of someone not taking birth control shortly after she discontinues using the medication.

5. Number of Periods

The more menstrual periods you have, the higher your risk of breast cancer. Those who started menstruating before the age of 12 or who began menopause after the age of 55 have more periods than the average person and thus have a higher risk of breast cancer.

6. Breastfeeding

Some studies suggest that breastfeeding can reduce your risk of breast cancer. One possible explanation for this is that breastfeeding reduces the number of periods you have in your lifetime.

7. Age During First Pregnancy

Women who never have a full-term pregnancy or who give birth to their first child after age 30 have a higher risk of breast cancer than those who have given birth earlier in life. The breast cells that form during puberty don’t fully mature and predictably grow until you have a full-term pregnancy. Another possible reason for this is that pregnancy reduces the number of periods you have throughout your life.

If you’d like to speak to a doctor about your risk of breast cancer or if it has been a while since your last mammogram, schedule an appointment with one of the skilled OB/GYNs at Baylor St. Luke’s Medical Group or find your nearest screening provider. If necessary, our team can recommend one of our experienced medical oncologists for additional care.


American Cancer Society | Lifestyle-related Breast Cancer Risk Factors
Breast Cancer | Breast Cancer Risk Factors
CDC | What Are the Risk Factors for Breast Cancer?
American Cancer Society | Breast Density and Your Mammogram Report
Breast Cancer | Pregnancy History
Breast Cancer | Drinking Alcohol

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