Geographic Distribution and Time Trends of Colorectal Cancer in Brazil from 2005 to 2018

Abstract

Background: Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of cancer-related death in the world. The aim of this study was to investigate the geographic distribution and time trends of CRC in Brazil.

Methods: Data were retrospectively retrieved from January 2005 to December 2018 from the Brazilian Public Health System. The incidence and lethality rates of CRC per 100,000 inhabitants in each municipality were estimated from hospitalizations and in-hospital deaths and were classified by age, sex, and demographic features.

Results: During the study period, the mean incidence of CRC estimated from hospitalizations and adjusted to available hospital beds more than tripled from 14.6 to 51.4 per 100,000 inhabitants (352%). Increases in CRC incidence were detected in all age ranges, particularly among people aged 50-69 years (266%). Incidence rates increased in all 5 macroregions, with a clear South to North gradient. The greatest changes in incidence and lethality rates were registered in small-sized municipalities. CRC lethality estimated from in-hospital deaths decreased similarly in both sexes, from 12 to 8% for males and females, from 2005 to 2018. The decline in lethality rates was seen in all age ranges, mainly in people aged 50 to 69 years (- 38%).

Conclusions: CRC incidence is increasing, predominantly above fifty years of age, and also in areas previously considered as having low incidence, but the increase is not paralleled by lethality rates. This suggests recent improvements in CRC screening programs and treatment, but also supports the spread of environmental risk factors throughout the country.

Keywords: Colorectal cancer; Ecological study; Geographic distribution; Hospitalization rates; Lethality rates; Time trend analysis.