Efficacy of A Fluoropyrimidine plus Mitomycin C in Pretreated Patients with Metastatic Colorectal Cancer Eligible for Regorafenib: A Retrospective Study

<strong>Objective:</strong> In the placebo-controlled CORRECT study, individuals with metastatic colorectal cancer (mCRC) receiving Regorafenib (RGR) achieved significant benefits in both median overall survival (OS: 6.4 months) and progression-free survival (PFS 1.9 months). Patients included in the study had previously failed all standard therapies, which must have included Fluoropyrimidines (FPDs), Oxaliplatin, Irinotecan, Bevacizumab, and Cetuximab or Panitumumab for <em>K-RAS</em> wild-type subjects. FPDs plus Mitomycin C (MMC) represent one of the few treatment options for mCRC patients currently eligible for RGR. We wanted to investigate the therapeutic benefit of this pharmacological association in the same clinical setting defined for RGR. <strong>Methods:</strong> We retrospectively evaluated the records of mCRC patients followed in our Institutions that would have fulfilled inclusion/exclusion criteria for the CORRECT trial and received instead the combination of FPDs and MMC. We therefore collected data from 87 patients: 61 fulfilled the criteria required for this analysis. <strong>Results:</strong> Median OS was 9.3 months (95% CI 9.0–15.4), with a median PFS of 3.3 months (95% CI 2.9–3.8). One third of the patients (29.5%) achieved disease control. No significant differences in OS and PFS were found between <em>K-RAS</em> WT and <em>K-RAS</em> mutant individuals. Likewise, Performance Status (PS) and the primary site of disease were not associated with differences in response rates. <strong>Conclusions:</strong> These results suggest the need for a prospective study assessing RGR cost-effectiveness compared to FPDs plus MMC for mCRC patients that progress after standard treatments