Prognostic value of the REBECCA prognostic score and the Tabernero classification in refractory metastatic colorectal cancer treated with regorafenib: a multicenter real-world study

Background: Regorafenib is a standard treatment option for patients with metastatic colorectal cancer (mCRC) refractory to conventional therapies. However, outcomes remain heterogeneous, and simple and reproducible prognostic tools applicable in routine clinical practice are needed to optimize patient selection. This study aimed to perform an external real-world validation of the REBECCA prognostic score and the Tabernero classification in a multicenter cohort of refractory mCRC patients treated with regorafenib. Methods: We conducted a retrospective multicenter study including 130 patients with refractory mCRC treated with regorafenib across five university hospitals in Galicia, Spain. Overall survival (OS), progression-free survival (PFS), and disease control rate (DCR) were analyzed according to the REBECCA prognostic score and the Tabernero classification. Kaplan–Meier estimates, log-rank tests, and chi-squared analyses were used to compare outcomes between prognostic subgroups. Results: Median age was 63 years, and 94.6% of patients had ECOG performance status 0–1. Median OS and PFS were 6.7 and 2.9 months, respectively. According to the REBECCA prognostic score, median OS was 9.2, 6.9, and 5.3 months for low-, intermediate-, and high-risk groups, respectively (p = 0.138). In contrast, the Tabernero classification identified significant OS differences, with median OS of 10.5, 6.9, and 5.2 months in patients with best, good, and poor prognostic characteristics, respectively (p = 0.022). DCR was also significantly stratified by the Tabernero classification (48.0%, 21.1%, and 24.4%; p = 0.004). Treatment was well tolerated, with a safety profile consistent with previous studies. Conclusions: In this multicenter real-world study, the Tabernero classification demonstrated robust prognostic stratification in a real-world setting in refractory mCRC patients treated with regorafenib, whereas the REBECCA prognostic score showed limited discriminatory ability in this contemporary cohort. Given its simplicity, objectivity, and reproducibility, the Tabernero model may represent a practical tool to support prognostic assessment and clinical decision-making in routine practice.