Small bowel wall edema induced by regorafenib is associated with regorafenib intolerance and shorter survival in patients with metastatic colorectal cancer: A retrospective study

Introduction Regorafenib, a receptor tyrosine kinase inhibitor, is a routinely used targeted agent in the current treatment of patients with refractory metastatic colorectal carcinoma (mCRC). The aims of this study were to detect the presence of bowel wall edema during regorafenib treatment via computed tomography (CT) and to assess the relationship between survival and regorafenib-induced bowel wall edema in patients with mCRC receiving regorafenib. Patients and methods We retrospectively evaluated the presence of bowel wall edema on CT of 25 mCRC patients who received regorafenib and analyzed its relationship with progression free survival (PFS) and overall survival (OS). Results Among the 25 patients, 25 had small bowel wall edema (SBWE) and 14 had large bowel wall edema (LBWE) on at least one CT examination. The median SBWE value was 4.85 milimeters (mm). Of the 25 patients, 14 had SBWE <= 4.85 mm and 11 had SBWE >4.85 mm. Regorafenib intolerance was significantly higher at SBWE >4.85 mm patients (p = 0.03). The median PFS was 4.6 months (95% CI: 2.4-6.8) and median OS was 9.3 months (95% CI: 3.1-15.4). Median PFS and OS were shorter in patients with SBWE > 4.85 mm than in those with <= 4.85 mm, but not statistically significant (median PFS: 3.9 vs 4.6 months, p: 0.523; median OS: 5.6 vs 9.3 months, p: 0.977). Conclusions Regorafenib caused SBWE in patients with mCRC. Patients who developed more SBWE had a higher regorafenib intolerance and a shorter survival. Further studies are needed to confirm the predictor value of SBWE on the survival outcomes of patients with mCRC receiving regorafenib.