William J. M. Hrushesky, MD

The population dynamics of cellular entry, traverse, and exit, through and from each phase of the cell cycle is coordinated throughout the day in the tissue of the human body. This coordination is particularly robust-ie, the daily peaks and valleys are particularly high and low-in tissues with the greatest average daily cellular proliferation. These tissues are also the most severely damaged by cancer treatments, most prominently cytotoxic drugs and ionizing irradiation.

Many patients with widespread cancer develop a hypoproliferative anemia,[1-3] which is often worsened by systemic cytotoxic chemotherapy. Some chemotherapeutic agents directly depress the capacity of bone marrow cells to proliferate,

Although the article by Senie and Tenser reviewing some of the data relevant to whether operative timing within the menstrual cycle affects breast cancer outcome is reminiscent of a recent paper that appeared in the December 1996 issue of the Journal of Women’s Health,[1] the question it considers is potentially important enough that this issue should also be raised in Oncology. The article points out the experimental basis for believing that an important interaction may occur between the host-cancer-surgery and the mammalian reproductive cycle.[2,3] This is an important supposition because clinicians have routinely assumed that no experimental foundation underlaid the first and 31 subsequent analyses of relevant clinical data[4,5]-an assumption that is false.