Sitting in the airplane from Los Angeles to Columbus where my two older daughters, 17 and 16, are competing for slots to represent the USA in the World Championships and Grand Prix events in diving, I am reviewing a manuscript that one of our fellows is planning to submit to a prestigious journal.
We are very excited by what we have found. It started more than 5 years ago, when we thought that we saw young females with colon cancer did worse than young males. We already knew that women are protected against colon cancer premenopausally, and large studies have shown that hormone replacement in postmenopausal women decreased colon cancer risk and polyp formation. We hypothesized that when a tumor develops under estrogen protection, the tumor might be more aggressive.
We initiated multiple projects to test our hypothesis. We looked at the role of estrogen in the development of colon cancer looking for estrogen (ER) expression and regulation in colon cancer and identified novel correlation between ER-beta and epidermal growth factor receptors (EGFR) which were associated with gender specific outcomes. We also looked in the SEER registry and studied over 50,000 patients with metastatic colon cancer.
We found that young women under the age of 45 live significantly longer than males, and this association was seen in all different ethnicities and was independent of stage, differentiation and all other important factors we check for.
This raises an important question: why do younger women do better than young men? We are suggest that estrogen is the main reason since older women do worse than men. Interestingly enough, the improved outcome in young women increased over the last 10 years with new colorectal cancer treatments further supporting a critical role of estrogen in the sensitivity of drugs used in metastatic colon cancer.
There are always questions from my female patients. Is it OK to use estrogen replacement? ABSOLUTELY. It seems not only to protect against the development of colon cancer but possibly has an impact on the prognosis. We plan to further study the impact and the mechanisms by which estrogen influence the outcome, so stay tuned.
We presented our data last year at ASCO and hope we can publish the results as soon as possible.
Sex does matter.