Outcomes with non-small cell lung cancer and brain-only metastasis.

Background: We evaluated outcomes in non-small cell lung cancer (NSCLC) patients who presented with brain-only metastatic (BOM) disease overall and by EGFR/ALK mutation status.

Methods: We analyzed clinico-demographic, treatment and survival data for all NSCLC patients who presented to our center between 2014 and 2016 with BOM as their first presentation of metastatic disease. Differences in overall survival (OS) were evaluated using log-rank tests for NSCLC wildtype (NSCLCwt NSCLC with an ALK-rearrangement/EGFR-mutation (NSCLCmut+).

Results: Of 109 patients with BOM, median age was 68 years; 51 % were female; 69 % Caucasian; 76 % ever-smoker; 76 % adenocarcinoma; and 25 % NSCLCmut+. While 41 patients (38 %) had subsequent brain-only progressive disease (PD), 22 (20 %) developed extracranial metastases. A higher proportion of NSCLCmut+ ( -wt) subsequently progressed outside the brain (37 % vs 15 %, p = 0.03). Median time-to-first-extracranial-metastases was 8.5 (NSCLCmut+ 21.0 months (NSCLCwt; p = 0.23).With 17.7 months median follow-up, median-OS was 15.9 months [95%CI: 11.5-21.3; all patients]; 12.3 [7.4-18.4; NSCLCwt] and 38.9 [21.3-not reached (NR); NSCLCmut+] (p = 0.09). In 33 of 80 patients with BOM, the primary tumor was treated with surgery or radiotherapy. In patients with NSCLCwt, there was no OS benefit associated with local lung tumor treatment (p = 0.68), whereas in NSCLCmut + pts, local lung tumor treatment correlated with greater OS (median-OS NR vs 21.5 months; p = 0.05).

Conclusion: In patients with NSCLCwt with BOM, we observed a -predominant pattern of brain-only secondary progression, however patients with NSCLCmut + more often progressed extracranially. In patients with NSCLCmut+ and BOM, definitive primary tumor treatment correlated with improved survival.