Improving the Odds for Breast Cancer Patients
Danielle Hayot, M.A., and Diana Zuckerman, Ph.D.
Women may be able to improve their chances of surviving breast cancer by timing their surgery carefully, according to a study published in the medical journal Cancer (November 15, 1999).
Women who underwent surgery on days 3-12 of their menstrual cycle had a 10-year survival rate of only 45% while those women whose tumors were removed on other days had a 10-year survival rate of 75%. The authors believe that the reason lies behind the varying levels of estrogen and progesterone released during the menstrual cycle. The high levels of estrogen released during the first half of the cycle (days 3-12) have been shown to stimulate the growth of the tumor. By contrast, progesterone, released during the second half of the cycle, may help to contain the tumor.
Molecules, called receptors, are sometimes found covering the surface of cancer cells. The presence of these receptors has been found to influence the degree to which the cancer cells respond to estrogen or progesterone. Scientists have hypothesized that women whose cancer cells are responsive to estrogen for example, may survive longer than women whose cells are not receptive to estrogen. Although this may seem to explain the higher survival rate of women undergoing surgery during the first half of their menstrual cycles, researchers found that timing plays an independent role in its relation to survival rates. Women who underwent surgery during the first phase of their cycles had equally low survival rates, regardless of whether estrogen receptors were present.
Since there is usually some flexibility in the timing of breast cancer surgery, women and their doctors may want to consider scheduling surgery during the second half of the patient’s menstrual cycle. Keep in mind that research on this topic is far from conclusive. The studies that have been done, including this one, include a relatively small number of participants (112 in this study) and assume that the women are experiencing regular 28-day cycles. If the women’s cycles are not regular, the women may not have been at the stage of their cycle that was assumed by researchers. Nevertheless, based on this and similar research, scheduling surgery during the second phase of a patient’s menstrual cycle is a good strategy, since it may increase the chances for survival. Even before this article was published, previous research had impressed Susan M. Love, M.D., the author of "Dr. Susan Love’s Breast Book," who wrote " I am starting to change my practice. After all, there are no side effects to changing the date of surgery, and only potential benefits" (Love, 1995).
The new study was conducted by Lucienne Cooper, M.Sc., Cheryl E. Gillett, Ph.D., Neera K. Patel, M.B., Diana M. Barnes, D.Sc., and Ian S. Fentiman, M.D., researchers at London’s Guy’s Hospital.
