Chronic hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC). In the process from chronic HBV infection to the development of HCC, there is a phenomenon of co-evolution of hepatocytes and HBV. The evolution of hepatocytes includes dedifferentiation and reverse evolution, while the evolution of HBV is mainly "telemorphosis" . Since HBV evolution occurs earlier than the development of HCC, the interaction between them is mainly reflected in the promotion of HCC evolution by HBV mutation. This article briefly summarizes the novel theory termed as cancer evolution and development and elucidates the molecular mechanism of HCC caused by HBV from the perspective of evolution.

Hydrological disasters are associated with infectious disease outbreaks and epidemics. Hydrological disasters will lead to water pollution, increased vulnerability to diseases, and increased density of vectors. These factors will facilitate the outbreaks of water-borne/food-borne diseases, vector-borne diseases, and air-borne/contagious diseases. Pre-event preparedness for disasters and post-event reconstruction of both disease surveillance system and water-supply system are key measures to prevent infectious disease outbreaks caused by hydrological disasters. This study reviews the domestic and overseas experiences of controlling infectious diseases after hydrologic disasters, outlines the spectrum of post-disaster infectious disease as well as their epidemiological characteristics, and provides practicable suggestions accordingly.

Objective: To describe the 40-years trend for the mortality of colorectal cancer (CRC) in Shanghai and to estimate the effect of age, period, and birth cohort with Age-Period-Cohort (APC) model. Methods: Data on tumor-releated death from 1975 Janurary 1 to 2014 December 31 was derived from the Yangpu District of Shanghai Center for Diseases Prevention and Control tumor registration system. Colonrectal cancer cases (C18.2-C18.9 and C20 in ICD10) were selected for analyses. Crude mortality, age-adjusted mortality, and Average Annual Percent Changes (AAPCs) were calculated for colon cancer and rectal cancer. The difference of AAPCs between male/female and different age groups were tested. An APC model (reference cohort and period were 1900 and 1975, respectively) was constructed to estimate the age-effect, period-effect, and cohort-effect on the colorectal cancer death. Results: During 1975-2014, 6 725 cases died of colorectal cancer (the cased of colon and rectal cancer were 3 684 and 3 041, respectively). The crude mortality and age-adjusted mortality of colon cancer was 8.83/100 000 and 6.76/100 000, respectively. The crude mortality and age-adjusted mortality of rectal cancer were 7.32/100 000 and 5.67/100 000, respectively. For population in Yangpu District, the crude mortality and age-adjusted mortality of colon cancer increased with time, and the crude mortality of rectal cancer increased with time (P<0.001). AAPC of the crude mortality rate (5.6%) and age-adjusted mortality rate (2.3%) of colon cancer were higher than those in rectal cancer (3.0% and -0.3%), respectively (both P values <0.001). AAPC of the crude mortality rate (males vs. females was 6.2% vs. 5.0%, P<0.05) and age-adjusted mortality rate (males vs. females was 2.7% vs. 1.7%, P<0.05) of colon cancer were higher in males than in females. APC model indicted that CRC-related death increased with age. During 1901 to 1941, the RR values of cohort effects for colon and rectal cancer death were 1.09-5.57 and from 1.04-2.28, respectively; During 1946 to 1991, the RR values of cohort effects for colon cancer and rectal cancer were 5.51-4.32 and 2.16-0.89. Conclusion From 1975 to 2014, the mortality of CRC in Yangpu District increased gradually, and colon cancer mortality in males increased faster than that in females. The risk of death from colorectal cancer in the 1946-1991 birth cohort declined.