Effect of Prophylactic Cranial Irradiation on Overall Survival in Metastatic Small-Cell Lung Cancer: A Propensity Score-Matched Analysis

Abstract

The role of prophylactic cranial irradiation (PCI) in metastatic small-cell lung cancer (SCLC) is controversial. Using the National Cancer Database we show that patients treated with PCI have improved survival outcomes. In light of conflicting randomized trials, this study adds information to help guide physician and patient decision-making about the utility of PCI in metastatic SCLC. Introduction: Patients with small-cell lung cancer (SCLC) have a high incidence of occult brain metastases and are often treated with prophylactic cranial irradiation (PCI). Despite a small survival advantage in some studies, the role of PCI in extensive stage SCLC remains controversial. We used the National Cancer Database to assess survival of patients with metastatic SCLC treated with PCI. Patients and Methods: Metastatic SCLC patients without brain metastases were identified. To minimize treatment selection bias, patients with an overall survival (OS) < 6 months were excluded. Cox regression identified variables associated with OS. Patients were propensity score-matched on factors associated with receipt of PCI or OS. The effect of PCI on OS was examined using Kaplan–Meier estimates. Results: In the overall cohort (n = 4257), treatment with PCI (n = 473) was associated with improved survival (hazard ratio, 0.66; 95% confidence interval, 0.60-0.74; P < 9 months (median: 15.3 vs. 12.9 months; P