Cholesterol metabolism is critical to the regulation of circulating hormonal levels in all of us. Cholesterol is the precursor to all steroid hormones — androgens, estrogens, cortisone derivatives and aldosterone (which regulates salt balance and blood pressure). It would therefore be no surprise if treatments designed to alter cholesterol metabolism had an effect on these other hormones. Now comes a provocative study published in the Journal of Clinical Oncology (click here for the abstract; Dr. Stark can send you the entire article if you request it on the form to the right) showing that women under treatment to try to prevent breast cancer recurrence have a better cancer-related outcome if they are simultaneously on drugs to lower cholesterol. As part of the BIG 1-98 trial in which women were given various combinations of hormone antagonists after breast cancer diagnosis, investigators kept track of the study participants’ cholesterol treatment. Most of the enrollees were not on cholesterol lowering drugs either at entry into the trial and were not put on them during the trial. 8010 women took part in this study; 637 were on cholesterol lowering medication (CLM) upon entry into the trial and another 697 began taking CLM during the trial. The latter group started these drugs presumably because measurement of serum cholesterol was done every 6 months as part of the monitoring process. Overall, whether you were on one of these drugs from the beginning, or started one of them during treatment, your risk of developing metastatic breast cancer was reduced from 17-25% depending on which subgroup within the trial you were in.
Dr. Stark comments: the effect of CLM treatment is a huge factor in estimating which women will live and which will die with breast cancer. Of course traditional variables — size of the primary tumor, number of involved lymph nodes — continue to be very important, but the effect of modifying cholesterol metabolism on breast cancer outcome is a stunning observation. More to come on this, to be sure.