Bone metastasis predicts poor prognosis of patients with brain metastases from colorectal carcinoma post aggressive treatment.

Purpose: The presence of brain metastasis (BM) in patients with colorectal cancer (CRC) is usually associated with terminal-stage illness; however, a subgroup of patients receiving aggressive treatment can have a satisfactory prognosis. This study was designed to investigate the profile of prognostic factors in CRC patients with BM treated aggressively.

Patients and methods: CRC patients with BM were retrospectively reviewed. Survival analysis was performed to identify potential prognostic factors in the entire cohort of patients and a subgroup of patients treated aggressively. Aggressive treatments included surgical resection, radiotherapy, and/or chemotherapy. Overall survival was defined as the time between the diagnosis of BM and death or until the date of the last follow-up visit.

Results: A total of 78 CRC patients were confirmed as having BM. Sixty-eight of them had extracranial metastases at the time of their BM diagnosis. The most common sites of extracranial metastases were lung (n=51, 65.4%), followed by liver (n=25, 32.1%) and bone (n=12, 15.4%). Fifty-one patients who were treated aggressively had significantly longer overall survival than those who accepted palliative care (14.1 months vs 2.0 months, P <0.0001). Multivariate analysis was applied, and the results showed that aggressive treatment (n=51), recursive partitioning analysis class I/II (hazard ratio [HR]=0.27, 95% CI: 0.12-0.6, P =0.001), and fewer BM (HR=0.4, 95% CI: 0.21-0.78, P =0.07) predicted longer survival. In contrast, the presence of bone metastasis, rather than lung or liver metastasis, at the time of diagnosis of BM (HR=2.38, 95% CI: 1.08-5.28, P =0.032) predicted a poor prognosis.

Conclusions: Although the prognosis of CRC patients having BM is frequently very poor, those with good performance status and few brain lesions responded to aggressive treatment, while those with bone metastasis at the time of diagnosis of BM had relatively dismal survival rates, even when treated aggressively.