September 27, 2020

Why are men more at risk of cancer than women?

There are diseases that do not affect both sexes equally. In the case of cancer, they are more susceptible to developing it. The lung was always related (although less and less since it begins to occur) with their bad habit of smoking. But why does cancer affect them more? A team from the Institute of Global Health of Barcelona (ISGlobal), promoted by ” la Caixa ”, has identified one of the main biological mechanisms that explain it. It is the loss of function of certain genes of the sex Y chromosome, present only in men.

The study, published in “The Journal of the National Cancer Institute”, was carried out in collaboration with the Pompeu Fabra, the University of Adelaide and the Genomic Center of Estonia.

After analyzing the data of 9,000 individuals, researchers have analyzed the function of all Y chromosome genes in several cancers. And, according to the results of their analysis, the probability of developing cancer increases when the function of six key Y chromosome genes in several cells is lost. “Recent studies had shown that as the cells of some men get older they tend to completely lose the Y chromosome, which is essential for sexual differentiation of the fetus,” says Juan Ramón González, study coordinator and head of the Bioinformatics Group in Genetic Epidemiology from ISGlobal. “Although the loss of the Y chromosome had previously been associated with a higher incidence in cancer, the causes of this relationship were unknown,” he adds.

These six Y chromosome genes are involved in the regulation of the cell cycle, a process that, when it fails, can lead to the development of tumors. “Interestingly, they are genes that have a similar copy on the X chromosome.” If this copy also mutates in the same cells, the possible biological protection of these genes against cancer is completely lost, ”explains Alejandro Cáceres, first author of the study.

Hence, it is essential to understand the biological differences between men and women with respect to cancer in order to develop personalized treatment and prevention lines. Especially when “men not only suffer more from cancer than women, but also have a worse prognosis. In fact, the lower life expectancy of men with respect to women is explained, in part for this reason, ”says González.

“While men may be more exposed to carcinogens because of their type of work or increase their risk to avoid further visits to the doctor, our study shows that there are biological factors that make the risk in men greater,” adds Cáceres .

In addition, the deletion of the Y chromosome can occur either by the loss of chromosome function, which would explain previous studies, or by other mechanisms mediated by the chemical inactivation of the same regions. Thus, “certain environmental exposures, such as tobacco and other toxins, could affect the function of the chromosome by altering its epigenetics,” González concludes.

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