Development of brain metastases in non-small cell lung cancer: High-risk features

Introduction: Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related death in the United States. The development of brain metastases (BM) in this disease is exceedingly common, affecting 20- 50% of patients. There is not a standardized screening protocol for brain metastases, which represents an opportunity to decrease disease burden in cancer patients. We aimed to analyze high risk factors for development of BM and propose indications for screening imaging.

Methods: We performed a retrospective review of over 1200 adults patients with histologically-documented NSCLC at our care center during a study period of 2011-2020, and analyzed data for primary outcome of brain metastases (BM) development, and secondary outcome of overall survival (OS).

Results: Significant risk factors for development of new BM after NSCLC diagnosis included younger age, larger size of primary lung tumor, Karnofsky performance score (KPS) < 70, liver or bone metastases, large cell histology, and family history of cancer. Factors associated with decreased OS were larger primary lung tumor, extracranial metastases at time of diagnosis, large cell histology, and poorly-differentiated carcinoma histology.

Conclusion : There are multiple high risk features for developing BM in NSCLC. These factors should routinely be investigated, and their presence should prompt screening brain MRI to promote early diagnosis and treatment of BM.