Parisi A, Cortellini A, Venditti O, Filippi R, Salvatore L, Tortora G, Ghidini M, Nigro O, Gelsomino F, Zurlo IV, Fulgenzi C, Lombardi P, Roselló Keränen S, Depetris I, Giampieri R, Morelli C, Di Marino P, Di Pietro FR, Zanaletti N, Vitale P, Garajova I, Spinelli GP, Zoratto F, Roberto M, Petrillo A, Aimar G, Patruno L, D'Orazio C, Ficorella C, Ferri C, and Porzio G
Background: Few data regarding post-induction management following first-line anti-epidermal growth factor receptor (EGFR)-based doublet regimens in patients with left-sided RAS/BRAF wild-type metastatic colorectal cancer (mCRC) are available., Methods: This multicenter, retrospective study aimed at evaluating clinicians' attitude, and the safety and effectiveness of post-induction strategies in consecutive patients affected by left-sided RAS/BRAF wild-type mCRC treated with doublet chemotherapy plus anti-EGFR as first-line regimen, who did not experience disease progression within 6 months from induction initiation, at 21 Italian and 1 Spanish Institutions. The measured clinical outcomes were: progression-free survival (PFS), overall survival (OS), adverse events, and objective response rate (ORR)., Results: At the data cutoff, among 686 consecutive patients with left-sided RAS/BRAF wild-type mCRC treated with doublet plus anti-EGFR as first-line regimen from March 2012 to October 2020, 355 eligible patients have been included in the present analysis. Among these, 118 (33.2%), 66 (18.6%), and 11 (3.1%) received a maintenance with 5-fluorouracil/leucovorin (5FU/LV)+anti-EGFR, anti-EGFR, and 5FU/LV, respectively, while 160 (45.1%) patients continued induction treatment (non-maintenance) until disease progression, unacceptable toxicity, patient decision, or completion of planned treatment. The median period of follow-up for the overall population was 33.7 months (95%CI = 28.9-35.6). The median PFS values of the 5FU/LV+anti-EGFR, anti-EGFR, 5FU/LV, and non-maintenance cohorts were 16.0 (95%CI = 14.3-17.7, 86 events), 13.0 (95%CI = 11.4-14.5, 56 events), 14.0 (95%CI = 8.1-20.0, 8 events), and 10.1 months (95%CI = 9.0-11.2, 136 events), respectively ( p < 0.001). The median OS values were 39.6 (95%CI = 31.5-47.7, 43 events), 36.1 (95%CI = 31.6-40.7, 36 events), 39.5 (95%CI = 28.2-50.8, 4 events), and 25.1 months (95%CI = 22.6-27.6, 99 events), respectively ( p < 0.001). After adjusting for key covariates, a statistically significant improvement in PFS in favor of 5FU/LV+anti-EGFR (HR = 0.59, 95%CI = 0.44-0.77, p < 0.001) and anti-EGFR (HR = 0.71, 95%CI = 0.51-0.98, p = 0.039) compared to the non-maintenance cohort was found. Compared to the non-maintenance cohort, OS was improved by 5FU/LV+anti-EGFR (HR = 0.55, 95%CI = 0.38-0.81, p = 0.002) and, with marginal significance, by anti-EGFR (HR = 0.67, 95%CI = 0.51-0.98, p = 0.051). No difference was found in ORR. Any grade non-hematological and hematological events were generally higher in the non-maintenance compared to the maintenance cohorts., Conclusion: Among the treatment strategies following an anti-EGFR-based doublet first-line induction regimen in patients affected by left-sided RAS/BRAF wild-type mCRC treated in a "real-life" setting, 5FU/LV+anti-EGFR resulted the most adopted, effective, and relatively safe regimen., Competing Interests: AlP reported receiving advisory board fees from GSK. AC reported receiving consulting/advisory board fees from AstraZeneca, MSD, Roche, and BMS and speakers’ fee from Novartis, Astellas, MSD, and AstraZeneca. AnP reported receiving fees from Eli-Lilly, MSD, and Servier. RG reported receiving fees from Amgen and Servier and advisory board fees from Amgen, Servier, Bayer, and Merck-Serono. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Parisi, Cortellini, Venditti, Filippi, Salvatore, Tortora, Ghidini, Nigro, Gelsomino, Zurlo, Fulgenzi, Lombardi, Roselló Keränen, Depetris, Giampieri, Morelli, Di Marino, Di Pietro, Zanaletti, Vitale, Garajova, Spinelli, Zoratto, Roberto, Petrillo, Aimar, Patruno, D’Orazio, Ficorella, Ferri and Porzio.)