Early morphological change for predicting outcome in metastatic colorectal cancer after regorafenib
Abstract
Background and Objective: The role of early morphological change (EMC) as a predictive marker for regorafenib treatment in metastatic colorectal cancer (mCRC) remains unclear. This study aimed to evaluate whether EMC could predict the treatment outcomes of mCRC patients receiving regorafenib.
Results: A total of 68 mCRC patients were included in the analysis. Among 52 patients with lung metastasis, 16 (31%) exhibited cavity formation (CF). The median progression-free survival (PFS) and overall survival (OS) for patients with CF were 4.2 and 9.2 months, respectively, compared to 2.4 and 6.5 months for those without CF (p<0.01 for PFS; p=0.09 for OS). Among 45 patients with liver metastasis, 14 (31%) showed active morphological response (MR). These patients had a median PFS of 5.3 months and OS of 13.6 months, compared to 2.4 months (PFS) and 6.9 months (OS) for those without active MR (p<0.01 for PFS; p=0.02 for OS). Overall, 25 patients (37%) demonstrated EMC, defined as either CF or active MR. The median PFS and OS in patients with EMC were 5.3 and 13.3 months, respectively, compared to 2.1 and 6.1 months in those without EMC (p<0.01 for PFS; p<0.01 for OS). Materials and Methods: This retrospective study included mCRC patients with lung and/or liver metastases who received regorafenib. CF in lung metastasis and MR in liver metastasis were assessed using the first post-treatment CT scan. EMC was defined as the presence of CF or active MR. We compared PFS and OS between patients with and without EMC. Conclusions: EMC appears to be a promising predictive marker for regorafenib treatment in mCRC patients.