OBJECTIVES:

Our aim was to systematically evaluate and compare the long-term benefit-harm balance of different screening strategies (colonoscopy or immunologic fecal blood testing (iFOBT) for individuals younger than age 50 with identified familial colorectal cancer (CRC) risk in Germany.

METHODS:

We developed and validated a Markov-state-transition model simulating CRC progression and management for individuals in Germany identified with familial CRC risk to evaluate various screening strategies differing in screening test (colonoscopy or iFOBT), interval, and age at start and end. We used German clinical and epidemiological data along with published test accuracy data from meta-analyses. We applied a lifelong time horizon. Evaluated outcomes included health benefits (CRC-related deaths avoided, life years gained [LYG]), potential harms (additional colonoscopies, colonoscopy-related severe complications [SC]), and incremental harm-benefit ratios (IHBR).

RESULTS:

In the base-case analysis, both benefits and harms increased with lower age for screening start and shorter intervals. When screening started before age 50, 32.4-35.5 CRC-related deaths per 1,000 screening participants were avoided with colonoscopy and 28.7-33.5 with iFOBT screening, compared to 28.7-31.4 (colonoscopy) and 28.0-30.2 (iFOBT) CRC-related deaths per 1,000 persons when starting age 50+, respectively. For iFOBT screening, the IHBRs expressed as additional colonoscopies/LYG were 1.3 (biennial, age 45-65 years vs. no screening), 3.5 (biennial, age 35-65 years), 6.0 (biennial, age 30-70 years) and 33.8 (annual, age 30-54 years; biennial, age 55-75 years). Corresponding IHBRs for 10-yearly colonoscopy were 3.7 (age 55-65), 9.9 (age 45-65 years), 14.6 (age 35-65 years) and 28.9 (age 30-70 years).

CONCLUSIONS:

Offering colonoscopy or iFOBT screening to individuals younger than 50 years with familial CRC risk in Germany may be beneficial. Depending on the acceptance for additional harms per additional unit of benefit, 10-yearly colonoscopy or alternatively biennial iFOBT from age 30 to 70 may be recommended for individuals with familial CRC.