'Disappearing' Y chromosome in aging men may worsen bladder cancer, mouse study shows

illustrated light red cancer cells being attacked by blue immune cells. an x chromosome can be seen in a cancer cell on the left side, which has no immune cells on it, while more immune cells are on another cancer cell to the right, which has both an x and a y chromosome

Most men carry one X and one Y sex chromosome in each of their body's cells. However, over their lifetimes, many men start losing Y chromosomes in a portion of their cells, and this might hamper their ability to fight certain cancers, a new mouse study suggests.

Loss of the Y chromosome in a percentage of men's cells may help cancer — specifically bladder cancer — sneak past the body's immune system and proliferate more rapidly, according to the study, published June 21 in the journal Nature.