Prognostic factors for 60-day mortality in first-line treatment of metastatic colorectal cancer (mCRC): individual patient analysis of four randomised, controlled trials by the AIO colorectal cancer study group

Abstract

BackgroundThe 60 day mortality is an established parameter for chemotherapy-related safety in randomised trials for metastatic colorectal cancer (mCRC). Prognostic factors associated with 60-day mortality would be helpful to identify high-risk patients in advance. Patients and methodsIndividual baseline patient data from four randomised, controlled trials from the Arbeitsgemeinschaft Internistische Onkologie (AIO) study group were retrospectively analysed. Chemotherapy consisted of fluoropyrimidine (5-FU/capecitabine), irinotecan, oxaliplatin with or without bevacizumab or cetuximab. Prognostic factors were identified by univariate and multivariate logistic regression models in two cohorts: one limited to ECOG PS 0 and 1 and one including ECOG PS 2 patients. ResultsA total of 1377 patients were evaluated. The analysis of ECOG PS 0, 1 and 2 patients consisted of 898 patients where a total of 33 deaths within the first 60 days of treatment (3.7%) occurred. In multivariate analysis, 60-day mortality was significantly associated with ECOG PS 2 and high leucocyte count (white blood cell, WBC). Odds ratio was 6.28 for WBC and 12.92 for ECOG PS 2. Exclusion of ECOG PS 2 patients but inclusion of one trial limited to ECOG PS 0 and 1 patients resulted in 1302 assessable patients and 44 early deaths (3.4%). In both cohorts, around 50% of deaths were disease related. WBC was confirmed as a significant risk factor for early death (OR 7.60). A combined score using ECOG PS 2 and WBC ≥8.000/µl is able to identify high-risk patients with a sensitivity of 18% and specificity of 98%. ConclusionsIn this large retrospective analysis of individual patient data, around 50% of early deaths were disease related. Elevated WBC was found strongly associated with increased 60-day mortality in first-line treatment of mCRC. The proposed AIO-60-Day-Mortality score serves as an additional trial exclusion criterion.