Why Do More Men Get Cancer than Women? Here's Why
Scientists are now prepared to provide an answer to what appears to be an age-old debate as to why cancer is more common in males than in females. Apparently, females carry an extra copy of protective genes in their cells.
Researchers from Boston and the Dana-Farber Cancer Institute finally offered a genetic explanation to this certain problem. Females apparently have an extra line of defense against cells growing out of control. While this is not the only one responsible for the "bias" toward men, the duplicate copies may account for the imbalance. This includes up the 80 percent of excess male cases of some tumors.
According to Andrew Lane, MD, PHD and Gad Gets, PhD, their data shows that males carry roughly a 20-percent higher risk than females of carrying cancer. This means an additional 150,000 cases every year. This spans across almost any kind of cancer.
The historic explanation pointed towards smoking or exposure to hazardous chemicals. However, when smoking rates dropped and occupational situations differed nowadays, the statistics still stayed the same.
Now men still outplace women in a lot of cancers such as kidney, renal, bladder and oral cancers. Apparently, according to Science Daily, the key lies in something called the KDM6A located on the X-chromosome. Apparently, it's a tumor-suppressor gene, the one that prevents cell division from spinning out of control.
One may expect that female cells are just as vulnerable to this mutation since one of the X-chromosomes shut down and remain that way for life. However, the KDM6A mutations appear more in male cancers. Apparently some genes of the deactivated chromosome "escape" and get to function normally. One of them tends to be a good copy o the KDM6A.
It now belongs to a line of genes called EXITS or Escape from X-Inactivation Tumor Suppressors.
They tested this hypothesis by scanning the genomes of more than 4,000 tumor samples, representing around 21 different cancer types. They looked for abnormalities such as mutations and checked whether these are common in male cells or female cells.
Apparently, of nearly 800 genes in the X-chromosome, six are frequently mutated in males. Of the six, five were known to escape the inactivation of the X-chromosome, making them viable EXITS genes.
The researchers are now encouraging more research on the matter, especially more statistical tests with enough patients and tumor tissue samples.