Clinical characteristics of colorectal cancer patients with brain metastases: An "Association des Gastro-Éntérologues Oncologues" (AGEO) multicenter study

Abstract

Background: Brain metastases (BM) from colorectal cancer (CRC) are rare (1-3%) but their incidence seems to be increasing due to improvement of CRC prognosis. The prognosis of patients with BM from CRC is poor. The objective of this study was to evaluate the clinico-biological criteria of CRC with BM. Methods: This multicenter retrospective study included all patients with BM from CRC between 1995 and 2015. Overall Survival was calculated using the Kaplan-Meier method. Results: A total of 135 patients were included. Mean age at diagnosis of CRC was 63.5 years [range 34-87] and 57.8% were men. Primary tumors were located preferentially in the rectum (37.1%) or sigmoid (24.3%). The median interval from CRC diagnosis to BM diagnosis was 34.2 months [IC95%: 28.2-38.7] and the one from the diagnosis of CRC metastases to BM diagnosis 20.7 months [IC95%: 13.2-26.1]. BM were mostly revealed by neurological symptoms (93.3%), predominantly unifocal (50.4%) and supratentorial (74.1%). At BM diagnosis, 71.1% of patients had lung metastases, 48.9% liver metastases and 11.9% had no extra-cerebral metastasis. BM resection was performed in 37.1% of the cases and 76.3% of patients underwent a brain radiotherapy. The mean overall survival from the time of BM diagnosis was 8.7 months [IC95%: 6.7-10.7], respectively 14.8 months [IC95%: 10.8-18.7] in the group of patients who underwent surgical resection versus 4.9 months [IC95%: 3.0-6.8] for the others (p < 0.0001). Overall survival was 12.3 months [IC95%: 9.0-15.7] for patients with unifocal BM versus 4.9 months [IC95%: 3.2-6.6] for patients with multifocal BM (p < 0.0001). Molecular analyses (RAS and BRAF) are ongoing and will be presented at the congress. Among the 34 CRC with available KRAS status, KRAS mutation was observed in 58.8% of the cases. Conclusions: The prognosis of patients with BM from CRC remains poor. Patients with BM from CRC have frequently lung metastases. The time between diagnosis of CRC metastases and BM raises the question of BM screening at 1-2 years of metastatic disease. Early detection of BM from CRC can allow curative-intent aggressive treatment with an expected benefit on survival and quality of life.