Trends in early onset colorectal cancer (EOCRC) in a South Asian cohort: data from a specialized tertiary care center in western Sri Lanka

Abstract

Introduction Early onset colorectal cancer [EOCRC] has significantly increased during the past decade globally. It is defined as cancers diagnosed in those aged 50 years or less. Most research on EORC are from western populations where the tumour biology and risk factors may differ from other regions. Evidence on EOCRC from the South Asian region is particularly scarce. This study presents the basic trends in presentation and overall survival [OS] pattern of EOCRC using data from a single specialized tertiary care institution over two decades. Methods A total of 723 patients treated at the University surgical unit of the North Colombo teaching hospital from 1995 to 2020 were included in the analysis. Overall survival of the EOCRC was compared with that of the older population using Kaplan- Meier survival curves. Survival patterns over two time periods [pre-2010 vs post-2010] were also compared between the two populations. The stage at presentation, family history of colorectal or related cancers, tumour site, and tumour stage were also compared. Results The proportion of EOCRC in this cohort has not shown a significant increase over the past two decades [2001-2010: 24% vs 2011-2020: 21%]. The advanced tumour stage at presentation and the presence of significant family history are also comparable. EOCRC cohort demonstrates a better OS for the entire study period [Median survival: < 50 years – not reached; >50 years – 91 months; 95%CI – 72-132; P<0.001]. However, this survival advantage is only observed during the pre-2010 period [Median survival: < 50 years – 160 months; 95%CI – 120 – not reached; >50 years – 84 months; 95%CI – 62-132; P=0.01] and becomes comparable in the 2010-2020 period [P=0.16]. OS of the EORC has not also improved over the two decades from 2001 to 2020 [P=0.51]. Conclusion There is no significant increase in the EOCRC rates in this population over time although the rate has remained high throughout. The OS of the EOCRC population is better compared to the older population. A significantly better OS is observed during the pre-2010 period in the EOCRC but is not present in the post-2010 period. Advancement in therapy may have improved the survival of the older population during the latter part but not that in the EOCRC due to its inherently aggressive nature. This paper provides preliminary data on EOCRC from Sri Lanka. The South Asian population may have a different disease pattern with younger age at onset compared to the western populations and needs to be further explored.