Isabelle Trouilloud, Nabil Baba-Hamed, Marie-Pierre Galais, David Tougeron, Romain Coriat, Jean-Philippe Metges, Olivier Bouché, Jean-Marc Phelip, Lola-Jade Palmieri, Laurent Mineur, Benoit Rousseau, Victoire Granger, Lea Saban-Roche, Pierre Michel, Julie Henriques, Jean-Marc Gornet, Emilie Soularue, Astrid Lièvre, Denis Smith, Dewi Vernery, Stéphane Obled, Gael Goujon, Christophe Locher, Anne-Laure Bignon-Bretagne, Gaetan Des Guetz, Sylvain Manfredi, Solene Doat, Bruno Buecher, Marie Dior, Carole Vitellius, Simon Pernot, Hôpital Cochin [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Institut Sainte Catherine [Avignon], Centre hospitalier universitaire de Poitiers (CHU Poitiers), Service d'Oncologie médicale [CHU Henri Mondor], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Henri Mondor, Centre Hospitalier Universitaire [Grenoble] (CHU), Hopital Saint-Louis [AP-HP] (AP-HP), CHU Bordeaux [Bordeaux], CHU Pontchaillou [Rennes], Centre Régional de Lutte contre le Cancer François Baclesse [Caen] (UNICANCER/CRLC), Normandie Université (NU)-UNICANCER-Tumorothèque de Caen Basse-Normandie (TCBN), Service d'Hépato-Gastro-Entérologie [CHU Pitié-Salpêtrière], CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN), Génomique et Médecine Personnalisée du Cancer et des Maladies Neuropsychiatriques (GPMCND), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire de Nîmes (CHU Nîmes), Centre Hospitalier Universitaire d'Angers (CHU Angers), PRES Université Nantes Angers Le Mans (UNAM), Centre Hospitalier Universitaire de Reims (CHU Reims), Institut de Cancérologie de la Loire Lucien Neuwirth, Centre Hospitalier Universitaire de Saint-Etienne (CHU de Saint-Etienne), Institut Curie [Paris], Hôpital Delafontaine, Centre Hospitalier de Saint-Denis [Ile-de-France], Centre Hospitalier de Meaux, CHU Saint-Antoine [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), AP-HP - Hôpital Bichat - Claude Bernard [Paris], Hôpital Louis Mourier - AP-HP [Colombes], CHU Dijon, Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), AP-HP Hôpital Bicêtre (Le Kremlin-Bicêtre), Interactions hôte-greffon-tumeur, ingénierie cellulaire et génique - UFC (UMR INSERM 1098) (RIGHT), Institut National de la Santé et de la Recherche Médicale (INSERM)-Etablissement français du sang [Bourgogne-Franche-Comté] (EFS [Bourgogne-Franche-Comté])-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Hôpital Michallon, Chemistry, Oncogenesis, Stress and Signaling (COSS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-CRLCC Eugène Marquis (CRLCC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service d'Hépato-Gastroentérologie [CHU Pitié-Salpêtrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], and Sorbonne Université-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université
Background Patients with RAS wild‐type (WT) nonresectable metastatic colorectal cancer (mCRC) may receive either bevacizumab or an anti‐epidermal growth factor receptor (EGFR) combined with first‐line, 5‐fluorouracil‐based chemotherapy. Without the RAS status information, the oncologist can either start chemotherapy with bevacizumab or wait for the introduction of the anti‐EGFR. Our objective was to compare both strategies in a routine practice setting. Materials and Methods This multicenter, retrospective, propensity score–weighted study included patients with a RAS WT nonresectable mCRC, treated between 2013 and 2016 by a 5‐FU‐based chemotherapy, with either delayed anti‐EGFR or immediate anti‐vascular endothelial growth factor (VEGF). Primary criterion was overall survival (OS). Secondary criteria were progression‐free survival (PFS) and objective response rate (ORR). Results A total of 262 patients (129 in the anti‐VEGF group and 133 in the anti‐EGFR group) were included. Patients receiving an anti‐VEGF were more often men (68% vs. 56%), with more metastatic sites (>2 sites: 15% vs. 9%). The median delay to obtain the RAS status was 19 days (interquartile range: 13–26). Median OS was not significantly different in the two groups (29 vs. 30.5 months, p = .299), even after weighting on the propensity score (hazard ratio [HR] = 0.86, 95% confidence interval [CI], 0.69–1.08, p = .2024). The delayed introduction of anti‐EGFR was associated with better median PFS (13.8 vs. 11.0 months, p = .0244), even after weighting on the propensity score (HR = 0.74, 95% CI, 0.61–0.90, p = .0024). ORR was significantly higher in the anti‐EGFR group (66.7% vs. 45.6%, p = .0007). Conclusion Delayed introduction of anti‐EGFR had no deleterious effect on OS, PFS, and ORR, compared with doublet chemotherapy with anti‐VEGF. Implications for Practice For RAS/RAF wild‐type metastatic colorectal cancer, patients may receive 5‐fluorouracil‐based chemotherapy plus either bevacizumab or an anti‐epidermal growth factor receptor (EGFR). In daily practice, the time to obtain the RAS status might be long enough to consider two options: to start the chemotherapy with bevacizumab, or to start without a targeted therapy and to add the anti‐EGFR at reception of the RAS status. This study found no deleterious effect of the delayed introduction of an anti‐EGFR on survival, compared with the introduction of an anti‐vascular endothelial growth factor from cycle 1. It is possible to wait one or two cycles to introduce the anti‐EGFR while waiting for RAS status., More than half of the cases of metastatic colorectal cancer harbor a RAS mutation; however, the time to obtain RAS status might be long enough to consider delayed anti‐EGFR treatment. This article reports on the two main treatment strategies for these cases.