Clinical characteristics and treatment outcomes of patients with colorectal cancer who develop brain metastasis: A single institution experience

Background: The development of brain metastasis (BM) in patients with colorectal cancer (CRC) is a rare and late event. We sought to investigate the clinical characteristics, disease course and safety using biologic agents in our patients with CRC who develop brain metastases. Methods: A retrospective review of patients with CRC with brain metastases treated at our institution from 01/2005-01/2015 was performed. Survival analysis was performed using the Kaplan-Meier method. Results: Forty patients were included in the analysis. Median age was 55.5 years, 67.5% were males, and 28% had a KRAS mutation. Twenty-four percent were treatment-naive at the time of BM diagnosis. Patients had a median of two brain lesions. Sixty-five percent of the patients were treated with radiotherapy alone, 22.5% had both surgical resection and brain radiotherapy. Median overall survival was 3.2 months after development of BM. Overall survival was longer in patients who received combined modality local therapy compared to patients treated with surgical resection or radiotherapy alone. Patients who received systemic treatment incorporating biologics following development of BM had a median overall survival of 18.6 months. Overall, the administration of biologic agents was safe and well tolerated. Conclusions: In summary, BM is an uncommon and late event in the natural history of metastatic CRC. The ability to deliver combined-modality local brain therapy as well as availability of more systemic therapy options appear to lead to improved outcomes.