Patients with brain metastases from gastrointestinal tract cancer treated with whole brain radiation therapy: prognostic factors and survival.

Abstract

To identify the prognostic factors with regard to survival for patients with brain metastasis from primary tumors of the gastrointestinal tract. Nine hundred and sixteen patients with brain metastases, treated with whole brain radiation therapy (WBRT) between January 1985 and December 2000 at the Department of Radiation Oncology, University Hospital Freiburg, were analyzed retrospectively. Fifty-seven patients presented with a primary tumor of the gastrointestinal tract (esophagus: n = 0, stomach: n = 10, colorectal: n = 47). Twenty-six patients had a solitary brain metastasis, 31 patients presented with multiple brain metastases. Surgical resection was performed in 25 patients. WBRT was applied with daily fractions of 2 Gray (Gy) or 3 Gy to a total dose of 50 Gy or 30 Gy, respectively. The interval between diagnoses of the primary tumors and brain metastases was 22.6 mo vs 8.0 mo for patients with primary tumors of the colon/rectum vs other primary tumors, respectively (P<0.01, log-rank). Median overall survival for all patients with brain metastases (n = 916) was 3.4 mo and 3.2 mo for patients with gastrointestinal neoplasms. Patients with gastrointestinal primary tumors presented significantly more often with a solitary brain metastasis than patients with other primary tumors (P<0.05, log-rank). In patients with gastrointestinal neoplasms (n = 57), the median overall survival was 5.8 mo for patients with solitary brain metastasis vs 2.7 mo for patients with multiple brain metastases (P<0.01, log-rank). The median overall survival for patients with a Karnofsky performance status (KPS) >=70 was 5.5 mo vs 2.1 mo for patients with KPS <70 (P<0.01, log-rank). At multivariate analysis (Cox Model) the performance status and the number of brain metastases were identified as independent prognostic factors for overall survival. Brain metastases occur late in the course of gastrointestinal tumors. Pretherapeutic variables like KPS and the number of brain metastases have a profound influence on treatment outcome.