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How long does it take until the effects of endoscopic screening on colorectal cancer mortality are fully disclosed?: a Markov model study
Author(s) -
Chen Chen,
Stock Christian,
Hoffmeister Michael,
Brenner Hermann
Publication year - 2018
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.31716
Subject(s) - colonoscopy , medicine , colorectal cancer , sigmoidoscopy , cumulative incidence , population , cancer , colorectal cancer screening , cumulative dose , demography , cohort , environmental health , sociology
A recent randomized trial has suggested persisting protection from colorectal cancer (CRC) incidence and mortality of a single flexible sigmoidoscopy for up to 17 years and possibly beyond. We performed a simulation study to explore the time course and magnitude of protection provided by screening colonoscopy against CRC death over 25 years. Using data from the German national screening colonoscopy registry, a multistate Markov model was set up based on the adenoma–carcinoma pathway to estimate cumulative CRC mortality when different proportions of the population have a single screening colonoscopy at age 55, or two screening colonoscopies at ages 55 and 65. Cumulative CRC mortality continuously increased with age and reached 2.6 and 1.7% at age 80 in the absence of screening for men and women, respectively. A single colonoscopy at age 55, even with limited uptake, would lead to much lower cumulative mortality (0.7% for men and 0.5% for women at age 80 under 100% uptake). Relative mortality reduction continued to increase over more than 10 years and reached the maximum around 12–13 years after screening. Absolute risk reduction steadily increased throughout follow‐up and more than half of the total risk reduction would occur between 15–25 years. A repeat colonoscopy 10 years later further enhanced the effects and cumulative mortality remained at 0.1–0.2% under 100% uptake. Even a single (once‐only) screening colonoscopy has the potential to prevent most of CRC mortalities. Protective effects are expected to be long‐lasting and to become fully manifest after more than two decades from screening.