OA07.07 PFS and OS Beyond 5 Years of NSCLC Patients with Synchronous Oligometastases Treated in a Prospective Phase II Trial (NCT 01282450)

There is increasing interest in the treatment of synchronous oligometastases of NSCLC. Two randomized studies demonstrated an increased PFS by adding a radical local treatment to systemic therapy in responding patients, but long-term data are lacking. We previously reported a median PFS of 12 months and a median OS of 13.5 months in 39 radically treated patients with synchronous oligometastases in a prospective study (De Ruysscher J Thorac Oncol 2012). As the minimal follow-up is now exceeding 6 years, we here report the long-term PFS and OS. Prospective single-arm phase II trial. The main inclusion criteria were pathologically proven NSCLC stage IV with less than five metastases at primary diagnosis, amendable for radical local treatment (surgery or radiotherapy). No previous response to systemic treatment was required. Forty patients were enrolled, 39 of whom were evaluable (18 men, 21 women); mean age was 62.1 ± 9.2 years (range, 44-81). Twenty-nine (74%) had local stage III; 17 (44%) brain, seven (18%) bone, and four (10%) adrenal gland metastases. Thirty-five (87%) had a single metastatic lesion. Thirty-seven (95%) of the patients received chemotherapy as part of their primary treatment. Median overall survival (OS) was 13.5 months (95% CI 7.6-19.4); 1-, 2-, 3-, 4-, 5, 6-year OS was 56.4%, 23.3%, 12.8 %, 10.3 %, 7.7 %, 5.1 % (2 patients), respectively. Median progression-free survival (PFS) was 12.1 months (95% CI 9.6-14.3); 1-, 2-, 3-, 4-, 5, 6-year PFS was 51.3%, 13.6 %,12.8 %, 7.7 %, 7.7 %, 2,5 % (1 patient), respectively. Of the 3 patients with a PFS after 5 years, 1 had a squamous cell cancer T2N2 with a single pathologically proven bone metastasis in the sternum, 1 had a NSCLC-NOS T4N0 with a single adrenal metastasis, and 1 a T1N2 adenocarcinoma with a pathologically proven contralateral lung metastasis. The latter patient is still free of disease. Two patients developed a second primary cancer: 1 tongue carcinoma after 70 months and 1 an adenocarcinoma in the contralateral lung after 71 months. Both patients died of their second cancer. Three patients (7.7 %) had a local recurrence, all in the PTV of their primary tumor. Only one patient was treated with a TKI (gefitinib) at progression. After radical treatment of oligometastases, approximately 8 % of the patients achieve a PFS after 5 years. Entering patients in trials combining local therapy with novel systemic agents (e.g. chemo-immunotherapy) remains mandatory.