Incidence of Colorectal Cancer in Selected Countries of Latin America: Age-Period-Cohort Effect

OBJECTIVE: To estimate Age-Period-Cohort effects on colorectal, colon and rectal cancer incidence rates in Latin American countries covered by high quality Population-Based Cancer Registries. METHODS: A trend study was performed using data from Cancer Incidence in Five Continents. Age-Period-Cohort effects were estimated by Poisson regression for individuals aged between 20 and 79 years with colorectal, colon and rectal cancers informed by Population-Based Cancer Registries from 1983 to 2012 in Cali (Colombia); from 1983 to 2007 in Costa Rica; and from 1988 to 2012 for both Goiânia (Brazil) and Quito (Ecuador). Goodness of fit model was tested using the deviance of the models. RESULTS: Age effect was statistically significant for both sexes in all Population-Based Cancer Registries areas and the curves slope reached peaks in the older age groups. There were cohort effects on the incidence rates for colorectal, colon and rectal cancers in all Population-Based Cancer Registries areas, except for women in Quito. Regarding the period effect, an increased ratio rate was observed in men (1.26, 95%CI 1.17 to 1.35) and women (1.23, 95%CI, 1.15 to 1.32) in Goiânia, between 2003 and 2007. CONCLUSIONS: In Latin America, age effect was observed on incidence rates for colorectal, colon and rectal cancers. Besides, birth cohort effect was identified for recent cohorts in both genders for colorectal, colon and rectal cancers in Cali and Goiânia, and cohort effect for colorectal and colon cancers in both genders in Costa Rica; while in Quito a cohort effect was only observed for rectal cancer among men. Period effect was observed in Goiânia with increased ratio rate in 2003-2007.