Testosterone and Androgen Receptor in Cancers with Significant Sex Dimorphism in Incidence Rates and Survival.

Several major cancer types exhibit significant sex dimorphism in incidence and survival. Whether and how sex as a biological factor impacts tumorigenesis, progression, and survival warrants full investigation, as such knowledge may lead to novel, precise prevention and treatment strategies. We reviewed epidemiological and molecular data on sex differences in cancers of the esophagus, bladder, head and neck, lung, liver, kidney, stomach, and skin melanoma, as well as the potential role of androgens and androgen receptor (AR) activity in these cancers. The potential molecular mechanisms are briefly discussed. Elevated testosterone (T) levels seemed to be associated with increased liver cancer and cutaneous melanoma incidences, and with reduced esophageal cancer risk. AR activity does not always correlate with T levels in tumorigenesis and progression. Higher AR expressions are associated with poorer survival in ESCC, whereas the role of AR in the survival of HNSCC and melanoma patients is inconsistent. The molecular impact of AR in liver cancer, kidney cancer, melanoma, and lung cancer is controversial. However, AR is likely to promote tumor growth and/or progression in esophagus, bladder, head and neck, and stomach cancers, and thus is associated with poor survival. Patients diagnosed with a tumor in this latter group could potentially benefit from therapeutic approaches targeting AR. Overall, the research on sex hormone androgens and AR in these cancers is limited. Further research is needed to determine a possible U-shaped relationship of T with cancer risk, and to decipher the role of testosterone and AR in some of these tumors to facilitate our understanding of sex dimorphism and to explore novel T/AR-based treatment options.