Prognostic Impact of Central Nervous System Recurrence After Surgery in Patients With Epidermal Growth Factor Receptor Mutation-positive Non-small-cell Lung Cancer

Abstract

Background/aim: Adjuvant therapy using third-generation tyrosine kinase inhibitors (TKI) demonstrated improved central nervous system (CNS) disease-free survival after surgery in patients with epidermal growth factor receptor (EGFR) mutation-positive lung cancer. However, the prognostic impact of CNS recurrence in surgical patients remains unknown. We evaluated the effect of CNS recurrence on post-recurrence survival (PRS) in patients with postoperatively recurrent NSCLC.

Patients and methods: We assessed the prognostic impact of CNS recurrence using a cohort from a prospective observational study (Kyushu University Lung Surgery Group Study 2: KLSS-2). Based on data from 340 patients in whom EGFR mutations were assessed among 498 total patients in the KLSS-2 cohort, factors related to CNS recurrence and prognosis after postoperative recurrence were analyzed.

Results: We noted no marked differences in the presence of EGFR mutations (p=0.14) between patients with CNS recurrence and those without CNS recurrence. Among the patients tested for EGFR mutations with stage IV recurrences (n=219), survival analysis of patients with EGFR mutations showed that the CNS group had a significantly poorer PRS than the no-CNS group (MST: 36.8 vs. 43.9 months, p=0.035). In multivariate survival analysis of stage IV EGFR mutation-positive cases, recurrence in multiple organs and recurrence of brain metastases were independent poor prognostic factors (hazard ratio=2.2, p=0.029; hazard ratio=3.2, p=0.0006, respectively).

Conclusion: Postoperative CNS recurrence was associated with a poor prognosis among patients with EGFR mutation-positive lung cancer in the period when third-generation EGFR-TKIs were not available. In EGFR mutation-positive lung cancer, prevention of CNS recurrence after surgery may improve post-recurrence prognosis.

Keywords: Non-small cell lung cancer; central nervous system; epidermal growth factor receptor mutation; post-recurrence survival; postoperative recurrence.