A review of the cost-effectiveness of genetic testing for germline variants in familial cancer.

Background : Targeted germline testing is recommended for those with or at risk of breast, ovarian and colorectal cancer. The affordability of genetic sequencing has improved over the past decade, therefore the cost-effectiveness of testing for these cancers is worthy of reassessment. Objective : To systematically review economic evaluations on cost-effectiveness of germline testing in breast, ovarian or colorectal cancer. Methods : A search of PubMed and Embase databases for cost-effectiveness studies on germline testing in breast, ovarian or colorectal cancer, published between 1999 to May 2022. Synthesis of methodology, cost-effectiveness, and reporting (CHEERS checklist) was performed. Results : The incremental cost-effectiveness ratios (ICERs; in 2021-adjusted US$) for germline testing vs. the standard care option, in hereditary breast or ovarian cancer (HBOC) across target settings were as follows: 1) population-wide testing: 344-2.5 million/QALY 2) women with high-risk: dominant-78,118/QALY, 8,337-59,708/LYG 3) existing breast or ovarian cancer: 3,012-72,566/QALY, 39,835/LYG 4) metastatic breast cancer: 158,630/QALY. Likewise, ICERs of germline testing for colorectal cancer across settings were: 1) population-wide testing: 132,200/QALY, 1.1 million/LYG 2) people with high-risk: 32,322-76,750/QALY, dominant-353/LYG 3) patients with existing colorectal cancer: dominant - 54,122/QALY, 98,790-6.3 million/LYG. Key areas of underreporting were inclusion of a health economic analysis plan (100% of HBOC and colorectal studies), engagement of patients and stakeholders (95.4% of HBOC, 100% of colorectal studies) and measurement of outcomes (18.2% HBOC, 38.9% of colorectal studies). Conclusion : Germline testing for HBOC was likely to be cost-effective across most settings, except when used as a co-dependent technology with the PARP inhibitor, olaparib in metastatic breast cancer. In colorectal cancer studies, testing was cost-effective in those with high-risk, but inconclusive in other settings. Cost-effectiveness was sensitive to the prevalence of tested variants, cost of testing, uptake and benefits of prophylactic measures. Policy advice on germline testing should emphasize the importance of these factors in their recommendations.