RESUMO
Primary gastric cancer (GC) is one of the most frequently diagnosed cancers worldwide.The incidence of GC in male is approximately twice the incidence thereof in female.Before 60 years of age, the male-female ratio of GC incidence has no geographic and ethic differences, and rises with the increase of age.Studies of classic and molecular epidemiology have proved that the sexual dimorphism in GC is due to synergetic effects of various factors including chronic infection, dietary habit, gene mutation, genetic susceptibility, estrogenic effects and differences in lifestyle behaviors, etc.Studies on the above-mentioned factors can not only help clarify the carcinogenesis of GC, but also help improve the strategies of GC control and prevention, and reducing GC incidence subsequently.
RESUMO
Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide.About 50% of the total number of HCC cases and deaths worldwide occurred in China.Male has high incidence rates of HCC.Epidemiological data showed that ratio between the male incidence of HCC and the female incidence was from 2∶1 to 5∶1 in China.Up to now, risk factors found to be able to give rise to the sexual dimorphism in HCC incidences include infection and mutation of hepatitis B virus, immune genetic susceptibility and functions of hormone receptors.Relevant studies can not only help clarify the specific biological processes of hepatocarcinogenesis, but also uncover the biological indications that associate the incidences and prognoses of HCC with the sexual dimorphism, thus playing an important role in improving the strategies of control and prevention.