In the United States, 1 in every 2 men will develop cancer at some point in their lifetime. For women, this number is 1 in 3. In the past this difference has been attributed to the fact that more men smoked cigarettes, and other factors such as a factory work environment. Though as more women entered the workforce and began to smoke, the cancer rates stayed the same. In fact, pediatric oncologists noted that males were more prone to childhood leukemia and other cancers, meaning that the increased rates cannot be attributed to lifestyle.
New research out of Harvard and MIT shows that the difference in cancer diagnosis rates may be caused by genetic differences between genders.
Andrew Lane, a physician-researcher at the Dana-Farber Cancer Institute, notes in Harvard Magazine that “men with certain types of leukemia often possess mutations on genes located on the X chromosome.” Since these mutations often damage the genes that suppress tumors, they make it easier for cancer to develop.
While men have one X chromosome, women have 2 – but in women, cells will randomly inactive one of their X chromosomes. This biological phenomenon is called X-inactivation. This should mean that men and women are equally likely to experience the X chromosome mutations that affect tumor-suppressing genes. But for reasons that are not yet clear to researchers, approximately 50 genes on females’ inactive X chromosome still function, and the tumor-suppressing gene is one of these.
In short, this means that women have a larger number of tumor-suppressing genes acting at a time than men, giving them some protection against cancer cells becoming cancer.
Research such as this gives us hope that we will soon be able to answer long-standing questions about cancer, and helps us to understand all types of cancer and how it occurs. For questions about this study or your risk factors for cancer, contact me at firstname.lastname@example.org.