P2.06-037 A Feasibility Study of Concurrent Chemoradiation Followed by Surgery for Pathologically-Proven Clinical IIIA-N2 Non-Small Cell Lung Cancer: Topic: Radiotherapy, TT Fields

Abstract

The standard treatment for stage IIIA-N2 non-small cell lung cancer (NSCLC) is definitive chemoradiotherapy. However, the strategy for resectable IIIA-N2 disease remains controversial. This phase II multi-institutional trial (WJOG5308L) was designed to evaluate the feasibility for neoadjuvant chemoradiotherapy followed by surgery (tri-modality) in patients with pathologically-proven N2 NSCLC. Patients with resectable IIIA-N2 (pathologically proven N2) were eligible. Neoadjuvant chemotherapy consisted of weekly paclitaxel (40mg/m2) plus carboplatin (AUC 2) for 5 weeks. Concurrent radiotherapy (RT) was prescribed with 50 Gy in 25 fractions to the mediastinum and primary tumor. Patients underwent surgical resection, unless PD disease, followed by two courses of paclitaxel plus carboplatin consolidation chemotherapy. The primary endpoint was complete resection (R0) rate. Secondary endpoints were progression-free survival, overall survival, response rate, protocol completion rate and morbidity/mortality. From December 2011 to November 2013, 40 patients were enrolled. The median follow-up time was 33.97 (7.2-46.3) months. The radiological responses to neoadjuvant chemoradiotherapy were as follows: no complete response, 23 (57.5%) partial response, 16 (40.0%) stable disease and one (2.5%) progression. 34 of 40 patients underwent surgery. Reasons for not receiving surgery were radiation pneumonitis (n=4), PD (n=1) and delay of protocol (n=1). Of 34 resections, twenty-eight were lobectomies, three were bilobectomies, two were pneumonectomies, and one was exploratory thoracotomy. Six patients underwent sleeve lobectomy, without any complication. Thirty-two patients achieved the primary endpoint, complete resection (R0) rate 80% (32/40). Pathological complete response (PCR) rate was 30.3%. Finally, 20 patients (50%) completed all planned tri-modality treatment. The 2-year progression-free and overall survival rates for all patients were 62.5% and 75.0%, respectively. The 2-year recurrence-free survival for patients who received R0 was 61.5%. Neutropenia was the main grade 3/4 morbidity and tolerable. 30-days mortality rate was 0%. Two treat-related deaths (late bronchial fistula) occurred. Sites of first disease recurrences were mediastinal lymphnodes (n=9, 22.5%), lung (n=8, 20%), and brain (n=4, 10%). Tri-modality treatment, neoadjuvant chemoradiotherapy followed by surgery, for resectable IIIA-N2 NSCLC seems feasible and promising.