Patients often wonder why they got a particular cancer. While we cannot know with certainty why a particular individual got a cancer, we know of risk factors that increase the odds of getting it. Today, we look at the association of hormone replacement therapy (HRT) and a particular type of breast cancer, lobular carcinoma.
The observation: Post-menopausal hormone replacement therapy can significantly increase the risk of the less-common lobular form of breast cancer.
What’s lobular carcinoma? This breast cancer subtype involves the lobules, grape-like structures in the breast that contain milk-producing glands. Lobular carcinoma accounts for only about 15 percent of all invasive breast cancers, and is typically hormonally sensitive. However, lobular breast tumors also present a clinical challenge because they can be more difficult to detect both by clinical examination and by mammography (as compared to the more common ductal cancer).
The data: In a study published in 2008 in Cancer Epidemiology, Biomarkers and Prevention, of more than 1,500 postmenopausal, western Washington women, my friend and colleague Christopher Li, MD found that current users of combined HRT had a 2.7-fold and 3.3-fold elevated risk of lobular and ductal-lobular cancer, respectively, regardless of tumor stage, size or number of lymph nodes involved. Only women who used combined HRT for three or more years faced an increased risk of lobular cancer. Among mixed ductal-lobular cases, hormone therapy increased the risk of tumors that were predominantly lobular but not tumors that had predominantly ductal characteristics.
Bottom Line: Postmenopausal women who take combined estrogen/progestin hormone-replacement therapy for three years or more face a fourfold increased risk of developing various forms of lobular breast cancer. I’m Dr. Michael Hunter.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. And have a great day!