Clinical outcome of node-negative oligometastatic non-small cell lung cancer

The concept of "oligometastasis" has emerged as a basis on which to identify patients with stage IV non-small cell lung cancer (NSCLC) who might be most amenable to curative treatment. Limited data have been available regarding the survival of patients with node-negative oligometastatic NSCLC.

Consecutive patients with advanced NSCLC who attended Kindai University Hospital between January 2007 and January 2016 were recruited to this retrospective study. Patients with regional lymph node-negative disease and a limited number of metastatic lesions (≤5) per organ site and a limited number of affected organ sites (1 or 2) were eligible.

Eighteen patients were identified for analysis during the study period. The most frequent metastatic site was the central nervous system (CNS, 72%). Most patients (83%) received systemic chemotherapy, with only three (17%) undergoing surgery, for the primary lung tumor. The CNS failure sites for patients with CNS metastases were located outside of the surgery or radiosurgery field. The median overall survival for all patients was 15.9 months, with that for EGFR mutation-positive patients tending to be longer than that for EGFR mutation-negative patients.

Cure is difficult to achieve with current treatment strategies for NSCLC patients with synchronous oligometastases, although a few long-term survivors and a smaller number of patients alive at last follow-up were present among the study cohort. There is an urgent clinical need for prospective evaluation of surgical resection as a treatment for oligometastatic NSCLC, especially negative for driver mutations.