Cost-Effectiveness of Colonoscopy-Based Colorectal Cancer Screening in Childhood Cancer Survivors

Abstract

Background: Childhood cancer survivors (CCS) are at increased risk of developing colorectal cancer (CRC) compared to the general population, especially those previously exposed to abdominal or pelvic radiation therapy (APRT). However, the benefits and costs of CRC screening in CCS are unclear. In this study, we evaluated the cost-effectiveness of early-initiated colonoscopy screening in CCS.

Methods: We adjusted a previously validated model of CRC screening in the US population (MISCAN-Colon) to reflect CRC and other-cause mortality risk in CCS. We evaluated 91 colonoscopy screening strategies varying in screening interval, age to start, and age to stop screening for all CCS combined and for those treated with or without APRT. Primary outcomes were CRC deaths averted (compared to no screening) and incremental cost-effectiveness ratios (ICERs). A willingness-to-pay threshold of $100 000 per life-years gained (LYG) was used to determine the optimal screening strategy.

Results: Compared to no screening, the US Preventive Services Task Force's average risk screening schedule prevented up to 73.2% of CRC deaths in CCS. The optimal strategy of screening every 10 years from age 40 to 60 years averted 79.2% of deaths, with ICER of $67 000/LYG. Among CCS treated with APRT, colonoscopy every 10 years from age 35 to 65 years was optimal (CRC deaths averted: 82.3%; ICER: $92 000/LYG), whereas among those not previously treated with APRT, screening from age 45 to 55 years every 10 years was optimal (CRC deaths averted: 72.7%; ICER: $57 000/LYG).

Conclusions: Early initiation of colonoscopy screening for CCS is cost-effective, especially among those treated with APRT.

Figure 1.

Colorectal cancer deaths and total costs ($) per 1000 CCS aged 25 years in 2017 under different colonoscopy screening scenarios. Colorectal cancer deaths (A) and total costs (B) are shown for no screening; colonoscopy every 10 years between age 50 and 75 years (US Preventive Task Force’s general population recommended colonoscopy screening strategy); colonoscopy every 5 years between age 30 and 75 years (the Children’s Oncology Group colonoscopy screening indication for CCS treated with APRT); and the corresponding optimal colonoscopy screening strategy suggested by our model (CCS all combined: colonoscopy between age 40 and 60 years every 10 years; CCS treated with APRT: colonoscopy between age 35 and 65 years every 10 years; and CCS not treated with APRT: colonoscopy between age 45 and 55 years every 10 years years). APRT = abdominal or pelvic radiation therapy; CCS = childhood cancer survivor; Col = colonoscopy; CRC = colorectal cancer.

Figure 2.

Model cost-effectiveness acceptability frontiers (CEAFs) for childhood cancer survivors (CCS) with primary cancer diagnosed at age 15 years. Results are shown for (A) all CCS; (B) CCS treated with pelvic or abdominal radiation; and (C) CCS not treated with pelvic or abdominal radiation. Uncertainty was assessed in a selected number of efficient screening strategies (the study’s optimal screening strategy, the corresponding previous less costly, and the corresponding subsequent more costly strategies). CCS = childhood cancer survivors; CEAF = cost-effectiveness acceptability frontiers; Col. = colonoscopy.