Whole brain radiotherapy (WBRT) for leptomeningeal metastasis from NSCLC in the era of targeted therapy: a retrospective study

BACKGROUND AND PURPOSE: Leptomeningeal metastasis (LM) is a rare but detrimental complication in patients with non-small cell lung cancer (NSCLC). Although whole brain radiotherapy (WBRT) is used to eliminating cancer cells or microscopic foci, it is becoming less favorable due to the concerns over neurocognitive toxicity. This study aimed to re-evaluate the role of WBRT in the setting of modern targeted therapy. MATERIALS AND METHODS: From December 2014 to March 2019, 80 NSCLC patients with cytologically and/or radiologically proven LM diagnosis were retrospectively analyzed. RESULTS: The median OS (mOS) after diagnosis of LM was 8.0 (95%CI: 4.4 to 11.6) months, and the one-year OS was 39.4%. The mOS for EGFR-mutated LM patients was 12.6 (3.0 to 22.2) months versus only 4.1 (2.8 to 5.4) for patients with wild-type EGFR (P < 0.001). Younger patients (< 53.5 yrs.) appeared to have a better OS than older patients (≥53.5 yrs.) (12.6 vs. 6.1, P = 0.041). No survival benefits were found in EGFR-mutated patients who received WBRT (P = 0.490). In contrast, mOS was significantly prolonged in wild-type EGFR patients with WBRT versus non-WBRT (mOS: 8.0 vs. 2.1, P = 0.002). Multivariate analysis indicated that WBRT (P = 0.025) and younger age (P = 0.048) were independent prognostic factors that predicted prolonged survival for wild-type EGFR LM patients from NSCLC. CONCLUSION: Our study demonstrated that WBRT has clear survival advantages for patients with wild-type EGFR, and molecular biological stratification of LM patients for WBRT is highly recommended.