Impact of high modified Glasgow Prognostic Score on regorafenib treatment in real-world metastatic colorectal cancer treatment

Regorafenib is the first multikinase inhibitor used for late-line treatment of metastatic colorectal cancer (mCRC) and is often administered using an initial dose-reduction strategy with weekly dose escalation according to its toxicity profile. The modified Glasgow Prognostic Score (mGPS), calculated from C-reactive protein and serum albumin levels, reflects cancer cachexia staging. This study assessed the impact of baseline mGPS on efficacy and safety in real-world regorafenib treatment for mCRC using an initial dose-reduction strategy. Patients with mCRC who received regorafenib monotherapy at an initial dose of 80–120 mg/day ( n = 70) were retrospectively evaluated and divided into a control group (mGPS 0) and a high-mGPS group (mGPS 1 or 2). The primary endpoint was progression-free survival (PFS). Median PFS was significantly shorter in the high-mGPS group than in the control group (49 [95% confidence interval [CI] 35–56] days vs. 63 [95% CI 51–114] days, P = 0.0007). Overall survival (OS) was also significantly shorter ( P < 0.0001), and the disease control rate was significantly lower ( P = 0.02) in high-mGPS group than those in the control group. All-grade hand–foot skin reaction was significantly less frequent and all-grade fatigue was significantly more frequent in the high-mGPS group than in the control group, although severe adverse events did not differ between groups. Secondary analyses showed significantly shorter PFS and OS in patients with mGPS 2 than in those with mGPS 1. High mGPS was associated with poor prognosis during real-world reduced-dose regorafenib initiation for mCRC.