Real-World Policy Effects of Implementing Multi-Gene Panel Sequencing for Advanced Cancers in British Columbia, Canada: An Interrupted Time Series Analysis

OBJECTIVES: Multi-gene panel sequencing may improve population health through identifying actionable therapeutic targets. Owing to uncertain clinical and economic impacts, health system uptake remains limited. Our objective is to estimate the real-world population mortality and health system expenditures impacts of cancer control policy implementing a 54-gene panel for advanced cancer care in British Columbia, Canada. We focus on two exemplar indications where panel testing replaced single gene testing and results either guided treatment selection or de-escalation.

METHODS: Drawing on population-based administrative health data, we identified patients diagnosed with advanced non-small cell lung cancer or metastatic colorectal cancer who received single gene or multi-gene panel testing between 2014 and 2018. We measured monthly mortality rates and mean monthly healthcare costs, following patients for up to 2 years after testing. Interrupted time-series analysis estimated immediate and gradual changes in outcomes from panel implementation in September 2016. Final models included autoregressive integrated moving average regressions of costs and generalized least squares Poisson regressions of mortality.

RESULTS: Over the period, 3,502 patients with advanced lung cancer and 1,330 with metastatic colorectal cancer were study eligible. In colorectal cancer, multi-gene panel implementation led to increasing mean per-patient healthcare costs of $61 per month (95% CI: $8, $113). In lung cancer, mean healthcare costs initially fell by $542 (95% CI: $303, $781), but savings were offset within 14 months by persistent increases in costs of $40 per month (95% CI: $26, $54). In both indications, greater systemic therapy costs drove overall costs, stemming from increasing access to expensive therapies. We failed to detect concurrent changes in mortality rates.

CONCLUSIONS: Individualizing patient care has population impacts for patients and healthcare systems. Implementation of multi-gene panel sequencing increased healthcare spending on expensive cancer therapies, regardless of therapeutic intent for testing. Population-level mortality did not justify higher spending.