Clinical significance of bifocal treatment for synchronous brain metastasis in T1-2 non-small-cell lung cancers: JNETS0301

Objectives The treatment of patients with brain metastases associated with non-small-cell lung cancer (NSCLC) is frequently challenging. Starting in 2003, we conducted a phase II study of surgery for patients with clinical T1-2N0-1 NSCLC with oligometastasis. The aim of this subset study was to assess the clinical significance of bifocal treatment for synchronous brain metastases in T1-2N0-1 NSCLC using prospectively collected data. Methods In this phase II study of clinical T1-2N0-1 NSCLC patients with oligometastasis, 47 patients were enrolled from December 2003 to December 2016. Among them, 18 NSCLC patients with synchronous brain metastases were investigated in this subset analysis. Results Fourteen patients underwent complete resection, and 4 underwent incomplete resection of the primary lung cancer. The number of synchronous brain metastases was one in 14 and multiple in 4 patients. After surgery for the primary lung cancer, 12 of 18 patients underwent treatment for their brain lesions, including stereotactic radiosurgery (SRS) in 10, surgical resection in 1, and SRS followed by surgical resection in 1. In 5 of the 18 patients (28%), the brain lesion was diagnosed as benign on follow-up radiological imaging. The 5-year overall survival rate after enrollment was 31.8% for all 18 patients and 35.2% for the 13 patients with brain metastases. Univariate analysis showed that having multiple brain lesions was a significant factor related to a worse prognosis. Conclusion For patients with suspected brain metastases associated with NSCLC, bifocal local treatment could be an acceptable therapeutic strategy, especially for solitary brain metastasis.