Y chromosome may expose men to greater cancer risk, study finds

Jan. 17 (UPI) -- DNA differences between men and women may explain why cancer risk is higher in males, a new study by researchers at the Barcelona Institute for Global Health suggests.

In findings published Friday in the Journal of the National Cancer Institute, the authors report that loss of function in certain genes of the sex-determining Y chromosome, which is present only in men, may cause them to have an elevated risk for cancer.

A landmark 2011 study found that men are up to five times more likely to receive a cancer diagnosis than women.

"Men are not only at higher risk of cancer than women, they also face a worse prognosis," co-author of the new study, Juan Ramón González, coordinator of the study and head of the Bioinformatic Group in Genetic Epidemiology at ISGlobal, said in a press release. "In fact, these differences partially account for the lower life expectancy of men. Although the loss of the Y chromosome has previously been associated with higher incidence of cancer, the causes of this association are poorly understood."

Recent studies have shown that complete loss of the Y chromosome, which is essential to fetal sex differentiation, occurs with aging in the cells of some men, he added.

The team at ISGlobal used data from 9,000 individuals to study Y-chromosome gene function in patients with various types of cancer. The findings showed that cancer risk increases with loss of function of six key Y-chromosome genes in various types of cells, which are involved in cell-cycle regulation, the failure of which can lead to tumor development, the authors said.

Suppression of the Y chromosome can occur as a result of loss of function in the chromosome or as a result of other mechanisms mediated by the chemical inactivation of the same regions, they added. Increased understanding of the biological differences between men and women in cancer may lead to the development of personalized lines of treatment and prevention.

"Certain environmental exposures, for example to tobacco or other harmful substances, could affect chromosome function and lead to epigenetic modifications," González said. "Our findings open the door for the development of targeted detection methods and specific therapies for men with cancer."