Some theories hold that lifestyle differences between men and women — such as diet and smoking — may account for the discrepancy. Yet growing evidence suggests that the differences are rooted in basic biological differences. Adding to that evidence, MIT researchers found that treating male mice with estrogen dramatically lowered their rates of stomach cancer. That same study found that estrogen — a hormone much higher in women — protects against gastric cancer.
Now, it’s unlikely that men will be treated with estrogen, but the findings could lead to treatments that mimic estrogen’s cancer-suppressing effects.
Gastric cancer is the second-leading cause of cancer deaths worldwide. People infected with “H. pylori” bacteria are much more likely to develop gastric cancer, as the infection provokes an immune response that can lead to inflammation of the stomach, which can then lead to cancer.
Several studies have suggested that estrogen protects women from this kind of inflammation. In the new one, the researchers waited until the mice had already developed inflammation before giving them estrogen. The male mice receiving estrogen did not develop cancer in spite of having inflammation, while 40% of the untreated mice did develop gastric cancer.
Among the female mice, those who received tamoxifen showed no differences from the untreated mice. That surprising finding suggests that, in the stomach, tamoxifen may mimic estrogen’s effects, rather than blocking them.
To figure out how estrogen protects against gastric cancer, the MIT researchers examined which genes were over-expressed in the treated mice. They found one that is involved in the immune response, promoting inflammation, and found that estrogen somehow interferes with the activity of these cells. It is very complicated genetic work, but the overall idea is that men are biologically more susceptible to stomach cancer — and we are well on our way to finding treatments that will suppress certain genes
and cells, and thus prevent cancer.
Onward and upward in the fight for cancer prevention.