[Analysis on incidence and mean age at diagnosis for Global Cancer]

Objective: To analyze the age distribution characteristics of different cancers in the world according to the database from Cancer Incidence in Five Continents published by the International Association of Cancer Registries, and to compare the age differences of cancer incidence in different regions. Methods: Cancer incidence data from volume XI of Cancer Incidence in Five Continents including 339 population-based cancer registries in 65 countries during 2008-2012 have been extracted. The average age of cancer incidence in different regions, gender and cancer sites were analyzed and stratified according to the human development Index and the level of national or regional development UN Development. The Segi's world standard population (world standard) was standardized to calculate the average age of the cancer incidence and to analyze the effect of age structure of the population on the average age of cancer diagnosis. Results: This study included 4 812 008 148 person-years in the global population (including 2 367 458 302 men and 2 444 549 846 women), and 21 892 093 of the new cancer cases, including 11 450 515 men and 10 441 578 women. The analysis showed that the average age of cancer incidence in the world was 65.73 years, and men and women were 66.70 and 64.67 years old, respectively. Among them, the average incidence age of testicular cancer was the youngest, with an average age of 36.67 years, and that of gallbladder cancer was the highest with average age of 71.55 years. After adjusting for population structure, the average incidence age was highest in gallbladder cancer, followed with bladder cancer and prostate cancer, and the testicular was with the lowest average age of incidence, followed by bone cancer and brain tumor. The results showed that the average age of cancer incidence in developed countries or regions was 66.38 years old, and that in less developed countries or regions was 61.75 years old, but in China it was 63.47 years old. According to the human development index (HDI), the higher the country or region with HDI, the higher the average age of cancer incidence, and the difference is reduced after the adjustment of the age structure of the population. Conclusions: There are different characteristics of the age distribution for different cancer sites. In terms of the age of cancer incidence, those of gallbladder cancer and bladder cancer are relatively old, while those of the testis, bone and thyroid cancer are relatively young. The average age of cancer incidence in China is between developed and less developed countries. Prevention and control of cancer should be carried out according to the age distribution characteristics of different cancers.