Background: Population aging and more prevalent westernized lifestyle would be expected to result in a markedly rising burden of colorectal cancer (CRC) in the future years. The aim of this study is to estimate the limited-time prevalence of CRC in Iran between 2015 and 2020.
Materials and methods: Aggregated CRC incidence data were extracted from the Iranian national cancer registry (IR.NCR) reports for 2003-2009 and from GLOBOCAN-2012 database for 2012. Incidence trends were analyzed by age groups, genders, histopathologic, and topographic subtypes to estimate annual percentage changes. Incidence was projected for 2020. The prevalence was estimated applying an adopted version of a previously introduced equation to estimate limited-time prevalence based on the incidence and survival data. Monte Carlo sensitivity analyses were applied to estimate 95% uncertainty levels (ULs). In each scenario, incidence, survival, annual percentage changes, and completeness of case ascertainment at IR.NCR were replaced under pre-assumed distributions.
Results: Number of estimated within 1, 2-3 and 4-5-year CRC patients in 2015 were 13676 (95% UL: 10051-18807), 20964 (15835-28268), and 14485 (11188-19293), respectively. Estimated 5-year prevalence for 2020 (99463; 75150-134744) was 2.03 times of that for 2015. Highest 5-year prevalence was estimated in ages 55-59 for females and 75 + for males. Adenocarcinoma (41376; 31227 55898) was the most prevalent histologic subtype. The most prevalent tumor location was colon (30822, 23262-41638).
Conclusion: A substantial growth in the prevalence of CRC survivors is highly expected for future years in Iran. Establishment of specialized institutes is highly recommended to provide medical and especially social supports for Iranian CRC survivors.
Keywords: Cancer; Iran; colorectal; modeling; prevalence; projection.