Sixty-four patients (25 females, 39 males) with 108 lesions were identified. Mean age was 62 years (SD: 12.10). Thirty-one patients (48.4%) had T1/T2 stage and 41 patients (64%) presented a N2/N3 stage. Not counting the metastatic sites, 45 patients (69%) presented a thoracic stage 3 disease. Thirty-eight patients (59%) had one metastatic site (17 patients (26%) and 9 patients (14%) had 2 and >3 metastatic sites, respectively). Main metastatic sites were: brain (34/64 patients, 53% of patients), bone (19/64 patients, 29%) and lung (4/64, 6%).
Most patients (84%) received platinum-based chemotherapy. Primary thoracic tumor was managed with concurrent chemo-radiation in 53 patients (83%), stereotactic body radiotherapy (SBRT) in 8 patients (12%) and surgery in 3 (5%).
The treatment of the metastatic sites was SRS in 21/64 patients (33%), surgery followed by post-operative SRS in 11/64 patients (17%), SBRT in 10/64 patients (15%) and conformal RT in 14/64 patients (21%).
The median follow-up was 27 months [range: 4-132 months]. The median OS was 36.6 months [CI95% : 23.5-50.2] and 1-, 2- and 5-years OS rates were respectively of 95%, 65% and 31%. The median PFS was 10.5 months [CI95%: 8.6-14.7] and 1-, 2- and 5-years PFS rates were respectively of 44%, 23% and 15%. The median time to initiation of a novel systemic therapy was 28.13 months [95% CI: 26.2-not reached].
The multivariate analysis suggested that the T stage (T1-2 versus T3-4) was an independent predictor of OS (HR= 1.03, IC95% :1-1.08 p= 0.02), whereas the thoracic stage (stage I-II versus III-IV) was an independent predictor on PFS (HR= 1.04, CI95%:1.003-1.07, p=0.05). Among the 54 patients who relapsed, 39 were oligo-recurrent, and 24 of them (24/39, 62%) subsequently received a subsequent local treatment only.