Authors:

Abstract

Background and Objectives: Oesophageal cancer is the seventh most commonly occurring cancer in men and the 13th most commonly occurring cancer in women world-wide. In Sri Lanka it is ranked as the fourth commonly occurring cancer. According to National Cancer Registry, Sri Lanka, in 2019, the age standardized incidence rate for males was 9.4 per 100,000 population while it was 5.3 for females. Globally, of the two histological types, squamous cell carcinoma is the most common type and accounts for the vast majority of cases; however, today, the proportion of adenocarcinomas is increasing dramatically in affluent nations. The aim of this study was to describe the trends of age standardized incidence rates of oesophageal cancer by sex, age specific incidence rates by age group and trends of crude incidence rates by the two main histological types (squamous cell carcinoma and adenocarcinoma) of oesophageal cancer in Sri Lanka from 2005 to 2019. Methods: Data already available in the National Cancer Registry maintained by the National Cancer Control Programme were extracted directly to calculate age standardized incidence rates and raw data were used to calculate age specific incidence rates and crude incidence rates for the period from 2005 to 2019. The data were coded using ICD 10 classification. The age groups were categorized as 0 to 49 years and 50 years and above. Trend analysis was done using version 4.9 of Join Point software. Average annual percentage changes were described with the 95% confidence interval. The models were selected for each trend considering the statistical significance which was set at α = 0.05 level. Results: There were 22,637 oesophageal cancer (OC) cases reported in Sri Lanka over the period of 2005 to 2019. Among them 12,294 (54.3%) were males and 10,343 (45.7%) were females. Squamous cell carcinoma accounted for 18,546 (81.9%) of cases and 2,469 (18.1%) were adenocarcimoma. The average annual percentage change (AAPC) of age standardized incidence rates (ASR) of OC in Sri Lanka for the period of 15 years from year 2005 to 2019 was 4.71 (95% CI 3.5 -6.0). The AAPC among males was 4.71 (p<0.05) and 0.24 for females which did not gain statistical significance. The AAPC of age specific incidence of oesophageal cancer for year 2005 to 2019 period were statistically significant for both age groups: 0 – 49 age group was 5.4 (95% CI -1.3 – 9.7) and 7.2 (95% CI 3.8 – 10.8) for 50 years and above age group. Both groups had p values of 0.0. From 2005 – 2019, the crude incidence rates of squamous cell carcinoma ranged from 4.23 – 6.17 per 100,000 population while crude incidence rates of adenocarcinoma ranged from 0.53 – 1.12 per 100,000 population. The AAPC of crude incidence rate of squamous cell carcinoma of oesophagus was 6.36 (95% CI 3.4 – 9.4) and 9.14 (95% CI 9.3 – 12.0) for adenocarcinoma. Both values were statistically significant with p values of 0.0. Conclusions: The age standardized incidence rates of males compared to females and the age specific incidence rate in the 50 years and above age group compared to 0 – 49 years age group were higher. The average annual percentage for sex and age group has also changed in the same direction. Although the crude incidence rate of squamous cell carcinoma remains higher compared to adenocarcinoma, the average annual percentage change was observed to be higher in adenocarcinoma.

Keywords: Oesophageal cancer, Adenocarcinoma, Squamous cell carcinoma

How to Cite: Fernando, M., Munas, M., Perera, U. and Dilhani, S., 2022. Oesophageal cancer in Sri Lanka: change of pattern over the past two decades. Journal of the College of Community Physicians of Sri Lanka, 27(5), pp.86–92. DOI: http://doi.org/10.4038/jccpsl.v27i5.8430