Prophylactic Cranial Irradiation for Extensive-Stage Small-Cell Lung Cancer: A Retrospective Analysis

Extensive-stage small-cell lung cancer (esSCLC) is an incurable disease and represents a therapeutic challenge because of its poor prognosis. Studies in prophylactic cranial irradiation (PCI) in esSCLC have shown a decreased incidence of symptomatic brain metastases in patients who respond to systemic chemotherapy. However, its effect on overall survival is debatable. We evaluated the benefit of PCI in patients with esSCLC in terms of overall survival, progression-free survival, incidence of brain metastases, recurrence rate, and exposure to postrecurrence therapies.

We retrospectively reviewed electronic charts from patients diagnosed with esSCLC from 2008 to 2014 at our institution. All patients had negative baseline brain imaging before chemotherapy and PCI and received at least 4 cycles of platinum-based chemotherapy in the first-line setting without progressive disease on follow-up. PCI was performed at the discretion of the treating physician. Analyses were based on descriptive statistics. Survival curves were calculated by Kaplan-Meier method.

Among 46 eligible patients, 16 (35%) received PCI and 30 (65%) did not. Compared with no PCI, PCI led to improved progression-free survival (median, 10.32 v 7.66 months; hazard ratio, 0.4521; 95% CI, 0.2481 to 0.8237; P < .001) and overall survival (median, 20.94 v 11.05 months; hazard ratio, 0.2655; 95% CI, 0.1420 to 0.4964; P < .001) as well as lower incidence of brain metastases (19% v 53%; P = .0273) and higher exposure to second-line chemotherapy (87% v 57%; P = .0479).

Careful patient selection for PCI can improve not only brain metastases control and higher second-line chemotherapy exposure but also patient survival.