We have just published our study on colon cancer clinical outcomes in women versus men. The facts that premenopausal women are protected against developing colon cancer and that postmenopausal women who take hormonal replacement therapy have reduced risk for colon cancer suggest that female hormones are protective. This can be very confusing since estrogen replacement therapy is not recommended for breast cancer patients.
In my laboratory we were interested in the role of estrogen in colon cancer. We found out that estrogen alpha is in the breast but beta in the colon. When colon cancer develops the cancer loses the estrogen beta receptor. We looked at whether the expression of this receptor is important, and found that it was associated with overall survival in patients with colon cancer (not published).
With these data we wanted to ask a very simple question: do young women better then men when diagnosed with metastatic colon cancer? We found they do much better, and it did not matter what ethnic background they were. We also checked if this difference changed with increasing treatment options and new drugs being used in the last 5 years and to our surprise, the difference became larger with new treatment options suggesting that women may benefit more from new therapies than men. We are now in the process to try to find out why. What does the estrogen do (other than the obvious) which links it to colon cancer and sensitivity to drugs and prognosis. This paper was just published in Clinical Cancer Research.
We also found out in that other genes which are important for efficacy and toxicity to 5-FU are dependent on gender which we published in Cancer Research (Zhang et al, 2009).