Aim: Colorectal cancer (CRC) is a common disease in the older population, but it has become increasinglyevident that it is also not infrequent in the young. The aim of this study was to describe the epidemiological,clinical and pathological characteristics of CRC in young Cambodians.
Methods: We examined clinical andpathological data from all CRC cases registered in the two reference centres for gastrointestinal tumours inCambodia between 2005-2010. Age-specific CRC incidence rates were computed using the national populationcensus 2008 data from the National Institute of Statistics. We compared differences in distribution of tumourlocation, histology, differentiation and UICC/TNM stage in two age groups, namely < 40 and ≥ 40.
Results:During this period, there were 356 new CRC cases, of which 29.8% affected patients younger than 40. Thisproportion is the second highest in the world, with a higher proportion only reported in Egyptian population.The crude incidence was 2.82 and 2.36 per 100,000 in females and males, respectively. Adenocarcinoma was themost common histologic type, and >50% of all tumours occurred in the colon, with no appreciable variationbetween the two age groups. Mucin-producing and advanced-grade tumours were twice more frequent in theyoung.
Conclusion: The unusually high CRC proportion in the young in our study could be due to referralbias. Nevertheless, together with the continuous exposure to hazardous environmental agents and the prevalentconsanguinity in Cambodia, this question warrants further research to advance our understanding of CRC riskfactors and perhaps genetic-environmental interactions in CRC epidemiology in young adults.