Colorectal cancer metastasis to the brain: A scoping review of incidence, treatment, and outcomes.

Abstract

<h4>Background</h4>Over 150000 new diagnoses of colorectal cancer (CRC) are diagnosed yearly, and 1 in 5 patients have distant metastases on diagnosis. Previous estimates approximate that brain metastases (BM) occur in 0.6% to 3.2% of patients with CRC.<h4>Aim</h4>To describe the updated literature about the incidence and risk factors of BM in CRC as well as their treatment with surgery, chemotherapy, and radiation.<h4>Methods</h4>We systematically searched the literature published between January 1, 2010 and April 1, 2025 in PubMed, Cochrane, Scopus, and EMBASE. All studies about BM from CRC were included. Studies only containing information about the treatment of primary CRC or primary brain tumors were not included. Articles were categorized and described as incidence, surgery, chemotherapy, or radiation to provide an overview of the state of research on BM from CRC.<h4>Results</h4>Our primary search resulted in 1648 articles that were eventually screened to 147. These articles were analyzed to provide the state of current literature on incidence and risk factors of BM from CRC as well as how these metastases are treated with chemotherapy, radiation, and surgery.<h4>Conclusion</h4>Prognosis is influenced by tumor burden, performance status, and emerging molecular markers. Stereotactic radiotherapy and surgical resection provide favorable outcomes for select patients, whereas chemotherapy and immunotherapy remain areas of limited evidence. Continued research is needed to identify high-risk patients and optimize multidisciplinary treatment approaches.