Informing metastatic colorectal cancer patients by quantifying multiple scenarios for survival based on real-life data.

Abstract

32 Background: Reported median overall survival (mOS) in trials of metastatic colorectal cancer (mCRC) patients receiving systemic therapy has increased to over 30 months. When informing patients, many clinicians quote the mOS reported in these trials. It is uncertain whether trial results translate to real-life populations. Moreover, patients prefer presentation of multiple survival scenarios over presentation of just mOS. Therefore, we quantified multiple scenarios for survival time of real-life mCRC patients. Methods: Nationwide population-based data of all stage IV CRC patients diagnosed between 2008 and 2016 were obtained from the Netherlands Cancer Registry. We calculated percentiles (scenarios) of OS per year of diagnosis for the total population, and for treatment subgroups: 10th (best-case), 25th (upper-typical), 50th (median), 75th (lower-typical), and 90th (worst-case). Results: The total study population comprised 27,275 patients. Twenty-five percent these patients did not receive any antitumor treatment. From 2008-2016, mOS of the total population remained unchanged at approximately 12 months. OS improved only for the upper-typical and best-case patients; by 4.2 to 29.1 months (p<0.001), and by 6.0 months to 62.0 months (p<0.001), respectively. No clinically relevant change was seen among patients who received systemic therapy, with mOS close to 15 months and best-case scenario approximately 40 months. mOS and worst-case scenario for survival were highest in patients who underwent both metastasectomy and systemic therapy: around 48 and 15 months, respectively. A clinically relevant improvement in survival over time was observed only in patients who initially received metastasectomy without systemic treatment. Conclusions: In contrast to the wide belief that mOS of mCRC patients receiving systemic therapy has improved substantially, improvement could not be demonstrated in our real-life population. Clinicians should consider quoting multiple scenarios for survival based on real-life data, instead of point estimates from clinical trials, when informing patients about their life expectancy.