"Antibiotic Use in Relation to the Risk of Breast Cancer," C.M. Velicer, et al., Journal of the American Medical Association 2004; 291: 827-835 Velicer, et al., reported that the "Use of antibiotics is associated with increased risk of incident and fatal breast cancer." Copyright 2004, James Michael Howard, Fayetteville, Arkansas, U.S.A. It is my hypothesis (1994) that low dehydroepiandrosterone (DHEA) may trigger oncogenes and that high testosterone may reduce DHEA, therefore increasing the probability of cancer. Both of these have since received support. For example, hormone replacement therapy decreases DHEA and HRT has been found to increase the incidence of breast cancer. Also, consumption of ethanol by women increases testosterone; alcohol consumption by women has been connected with increased breast cancer. ("How 'Hormone Replacement Therapy' (HRT) May Cause Breast Cancer" at www.anthropogeny.com/research.html .) It is known that DHEA exerts protective effects against many forms of infections, including bacteria. I suggest the connection of increased breast cancer in women who have required antibiotics is low DHEA. That is, low DHEA in these women reduced their immune response which subsequently required the aid of antibiotics. I suggest the increased incidence of breast cancer in these women is reduced DHEA, not antibiotics. James Michael Howard www.anthropogeny.com