Long-term Survival in Non–Small Cell Lung Cancer Patients with Metachronous Brain-Only Oligorecurrence Who Underwent Definitive Treatment

PURPOSE: Metachronous brain-only oligorecurrence in patients with non–small cell lung cancer (NSCLC) is a rare event with favorable prognosis, but the clinical outcome has not been fully determined. We retrospectively analyzed clinical outcomes and prognostic factors in metachronous brain-only oligorecurrence in patients with NSCLC who underwent definitive treatment. MATERIALS AND METHODS: We reviewed 4,437 NSCLC patients without oncogenic driver mutations who underwent definitive treatment between 2008 and 2018. Among them, we identified 327 patients who developed 1 to 5 brain metastases with or without systemic metastasis. Of the 327 patients, 71 had metachronous brain-only oligorecurrence without extracranial progression and were treated with local therapy to the brain. Overall survival (OS), progression-free survival (PFS), and prognostic factors affecting OS were analyzed. RESULTS: The median OS was 38.9 months (95% confidence interval [CI], 21.8 to 56.1 months) in 71 patients. The 2-year OS rate was 67.8% and the 5-year OS rate was 33.1%. The median PFS was 25.5 months (95% CI, 12.2 to 14.4 months). The longest surviving patient had a survival period of 115 months. Through multivariate analysis, Eastern Cooperative Oncology Group ≥ 1 (hazard ratio, 5.33; p=0.005) was associated with poor survival. There was no significant difference in OS between patients with local therapy and those with local plus systemic therapy (18.5 months vs. 34.7 months, p=0.815). CONCLUSION: Metachronous brain-only oligorecurrence NSCLC patients who underwent definitive treatment experienced long-term survival with local therapy, highlighting the unique patient population. The role of systemic chemotherapy in this patient population requires further investigation.