Komori A, et al. – In order to find out whether serum carbohydrate antigen 19-9 (CA19-9) response was an early predictive marker of efficacy of regorafenib in refractory metastatic colorectal cancer, experts undertook this study. As per the results, early response of CA19–9 could predict the efficacy of regorafenib.

Methods

• 146 consecutive mCRC patients who received regorafenib, were retrospectively examined.
• In order to determine efficacy predictors, clinical parameters, including patient background, adverse events (AEs) , and changes in biochemical parameters until day 28, were evaluated.

Results

• As per observations, median progression-free survival (PFS) was 2.1 months, and median overall survival was 6.6 months.
• Hand-foot skin reaction, hypertension, and increased aspartate transaminase were major AEs in all cycles.
• 121 patients were extracted for prognostic analysis.
• Decreased carcinoembryonic antigen (HR: 0.570, p = 0.012) and decreased carbohydrate antigen 19-9 (CA19-9) (HR: 0.422, p = 0.0012) were identified as prognostic markers of PFS, in univariate analysis.
• In comparison to those in whom serum CA19-9 did not decrease, patients in whom serum CA19-9 decreased after regorafenib exhibited significantly better PFS (median 3.7 vs. 2.0 months, p = 0.004).
• Early CA19-9 decrease was highlighted as an independent predictive factor (HR: 0.415, 95% CI: 0.210-0.818, p = 0.011).