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

BACKGROUND: The 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 METHODS: Individual 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. RESULTS: A 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%. CONCLUSIONS: In 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.