Sex chromosome loss linked to cancer growth and outcomes.

Two new studies published in the journal Nature have found that genetics can explain why sex matters in certain cancers. In bladder cancer, men with tumors that have lost the Y chromosome fare just as badly as women, as the immune system doesn't function as well. Existing immunotherapy drugs that take the brake off T cells are more effective in bladder cancers that have lost their Y chromosomes than in those that still have it. In some colon cancers, the presence of the Y chromosome can worsen outcomes, suggesting the Y chromosome works differently depending on the type of cancer. Identifying sex differences in cancer can call attention to patients at higher risk for recurrence and therefore in need of closer surveillance and potentially additional therapies.