DEAR DR. ROACH: I am 51 years old, very healthy and fit. I run 20 miles a week, competitively. I had a sonogram, which revealed a growth in my breast. It was removed during excisional biopsy, and I was told that I have LCIS (lobular carcinoma in situ). This puts me at a very high risk for getting breast cancer. My yearly mammograms have always been fine, although I have very dense breast tissue.

I go for my first breast MRI in May, and I hope that it does not show a hidden cancer. If it does, I hope it is a very early stage. I will be meeting with an oncologist next week to discuss drug treatments to lessen my chance of ever getting breast cancer in the future. I had a hysterectomy a few years ago, and I had my uterus removed, but not my ovaries. I hope that these two conditions do not put me at a disadvantage for getting a worse type of cancer. I also hope it is more of just a marker or a red flag. I hope my quality of life will not suffer from all of the side effects I may be getting from the drug I will be taking. What are your thoughts? I am feeling very down and out. — D.M.

ANSWER: LCIS was formerly thought to be a type of breast cancer, but it is now thought to be a more ”indolent” lesion, meaning that it has very low likelihood of acting like a cancer. However, it does put you at higher risk for developing invasive breast cancer, so you are correct that it is a ”red flag,” requiring your doctors to watch you more carefully; the risk is about 1 percent per year. In 12 years of follow-up in one study, 5 percent of women had breast cancer on the same side as the LCIS, and 5.6 percent developed breast cancer on the other side. Women under the age of 40 at the time of diagnosis are at a higher risk. A history of hysterectomy (uterus removal) does not affect breast cancer risk.

With a high risk of developing breast cancer, early diagnosis and prevention are both reasonable to consider. MRI is a very sensitive way of diagnosing breast cancer early, but it’s not specific: It finds many lesions that turn out not to be breast cancer, and that means many women will need biopsies that turn out to be unnecessary. Studies are ongoing, but so far there is no proven benefit to MRI compared with standard imaging (mammograms and sometimes ultrasound if appropriate, such as in women with dense breasts).

Medication to prevent cancer has been shown to be effective in women with a history of LCIS. Women given the drug tamoxifen had a 0.63 percent risk of breast cancer per year, compared with 1.17 percent of women given a placebo. Tamoxifen often causes many symptoms, often similar to those of menopause.

Regular exercise is associated with a decreased risk for breast cancer, so keep up your running. Being down and out after this diagnosis is perfectly understandable, but staying with your healthy exercise regimen can help with that, too.

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, FL 32803. Health newsletters may be ordered from www.rbmamall.com.

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