MALE SEX HORMONES have been shown to hinder the body’s ability to combat bladder cancer. A recent study has speculated that this may explain why cancer rates are higher in males, as well as more fatal forms of the disease. This study could contribute to advancements in the understanding of the discrepancies in cancer prevalence and prognosis between males and females.
Senior author of the study, Xue Li, Research Scientist at Cedars-Sinai Medical Center, Los Angeles, California, USA, noted: “We observed that biology of sex, not just behaviour, is an important factor in cancer development.” In males, there are high levels of androgens produced for promotion of the reproductive system. Li and co-authors found evidence that these sex hormones interfere with the adaptive immune system through blocking the activity of CD8+ T cells. With research taking place in a murine bladder cancer model, it was noted that more aggressive cancers were present in male mice, supporting the observation in humans.
The investigators found through the experimental removal of different immune cells that the observed disparities in cancers ceased following the removal of CD8+ T cells. Following genetic sequencing of the tumour CD8+ T cells, the scientists noted that those found in male mice showed higher levels of exhaustion and dysfunction, likely attributed to androgen activity. A significant reduction in bladder size was noted following androgen deprivation therapy, which also positively impacted immunotherapy responses. Li commented: “Unfortunately, many cancer patients do not respond to immunotherapy. These findings suggest male patients may benefit more from immunotherapy when combined with androgen deprivation therapy.”
Going forward, Li and co-authors will continue to investigate the impacts of androgen-inhibiting therapy on the treatment of bladder cancer, including the optimal time to begin treatment.