Brain metastases in newly diagnosed colorectal cancer: a population-based study

Population-based incidence evaluations and prognosis assessments of brain metastasis (BM) at diagnosis of colorectal cancer (CRC) are lacking. Our study sought to determine the incidence of BM in CRC patients, median survival of patients with BM, and the risk factors of BM in CRC.

Patients diagnosed with CRC were identified using the Surveillance, Epidemiology, and End Results database. Multivariable logistic and Cox regression analyses were performed to identify predictors of the presence of BM at CRC diagnosis and the factors associated with poor survival. Kaplan-Meier analysis was used to estimate the survival difference between subgroups.

We identified 170,793 adult patients diagnosed with CRC between 2010 and 2013. From these patients, we identified 401 patients with BM at the time of CRC diagnosis, which represents 0.23% of the entire patient CRC cohort and 1.3% of the patients with metastatic disease to any site. Median survival of patients with BM was 7.0 months, and the survival could increase to 15.59 months if there was no metastasis to other organs. We found that extracranial metastases number, tumor site, and pathology type were associated with BM at CRC diagnosis.

The findings of this study indicate the incidence and prognosis for patients with BM at the time of CRC diagnosis. Our findings lend support for positive treatment for BM without metastasis to other organs.