Predictive factors of severe early treatment-related toxicity in patients receiving first-line treatment for metastatic colorectal cancer: Pooled analysis of 2190 patients enrolled in Fédération Francophone de Cancérologie Digestive (FFCD) trials

•Severe drug toxicity has a negative impact on prognosis in metastatic colorectal cancer.•Early toxicity within 3 months after first-line regimen initiation may be a key factor.•Early grade III or more toxicity is a new prognostic marker.•Some baseline characteristics are associated with ET3 occurrence.•Early grade III or more toxicity correlates with poorer overall survival.