Examining the survival benefit of radiation therapy on leptomeningeal carcinomatosis and identifying factors associated with survival benefit of whole-brain radiation therapy

Abstract

Today, there are no conclusive data on the survival benefit from radiation therapy for leptomeningeal carcinomatosis (LMC) patients. The purpose of this article is mainly two folds: first, to report the survival benefit of radiation therapy (RT) in LMC patients with breast or lung as primary cancer and second, to identify the factors of LMC patients that had survival benefit from whole brain radiation therapy (WBRT). Systematic literature review was performed. Search terms included ‘Leptomeningeal’, ‘prognostic factors’ and ‘lung’ or ‘breast’. Literatures were included if patient profile was reported. Specifically, age, median survival, diagnosis time line, type of cancer, received treatments, performance score, and systemic disease were sought after. Literature were excluded if they were a) case reports, b) written in language other than English, or c) not including patient profile. For LMC patients with primary breast cancer, 7 studies were found since 1991 that met searching criteria. Factors which would allow breast cancer-caused LMC patients to benefit from WBRT with survival are identified with statistical significance. They include Karnofsky (KPS) >60, Intrathecal (IT) chemotherapy, systemic therapy, hormonal receptor status and severity of systemic disease. Patients who met aforementioned criteria and received WBRT had longer median survival (17 weeks vs 11.9 weeks, P = 0.015). Similarly, 10 studies were found that met searching criteria for non-small cell lung cancer (NSCLC) caused LMC. Beneficial factors for NSCLC-caused LMC are identified. They include IT chemotherapy, KPS > 60, and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment. Patient who met these criteria had longer median survival when received WBRT (17.6 weeks vs 12.2 weeks, p = 0.0412).