Five-year survival outcomes from CRES ³ T: S-1 plus cisplatin with concurrent radical-dose radiotherapy followed by surgery for superior sulcus tumor.

8064 Background: CRES 3 T is a multicenter, single-arm, confirmatory trial of S-1 plus cisplatin and concurrent radical-dose thoracic radiotherapy (TRT) followed by surgery in patients with superior sulcus tumor (SST). The 3-year overall survival (OS) and progression-free survival (PFS) rates were 73% (95% confidence interval [CI]; 60–83%) and 53% (95% CI; 40–65%), respectively. The primary endpoint, 3-year OS rate, was met. We report the exploratory analyses of survival outcomes approximately 5 years after the last patient was enrolled. Methods: Patients with SST (pathologically proven non-small cell lung cancer that directly invades the chest wall, including the first rib or further cephalad, subclavian artery, or subclavian vein according to computed tomography or magnetic resonance imaging) received induction therapy comprising three cycles of S-1 plus cisplatin with concurrent TRT (66 Gy in 33 fractions) followed by surgery. S-1 was administered orally at 40 mg/m 2 twice daily for 14 days along with an intravenous infusion of cisplatin (60 mg/m 2 ) on day 1. The treatment cycles were repeated every four weeks. The 5-year OS, 5-year PFS, and patterns of postoperative recurrence were analyzed. Prognostic factors of OS were analyzed in patients who underwent surgical resection using Cox proportional hazard model. Results: The median follow-up duration for 60 eligible patients was 67.1 months. The 5-year OS and PFS rates were 66.3% (95% CI; 52.8–76.8) and 48.1% (95% CI: 35.0–60.0), respectively. The median follow-up duration for 49 patients with surgical resection was 71.0 months. The 5-year OS and PFS rates were 71.0% (95% CI; 56.0–81.7) and 52.8% (95% CI: 37.9–65.6), respectively. Age was the only significant prognostic factor for OS ( P = 0.01, HR 1.1, 95% CI; 1.02–1.20). Sex, smoking status, clinical T stage, clinical N stage (cN0 versus cN1/ipsilateral supraclavicular cN3), symptoms associated with brachial plexus involvement, histology, preoperative serum CEA and CYFRA levels, pathological complete response, and major pathological response had no significant prognostic impacts on OS. Twenty (41%) patients developed postoperative relapse. The patterns of postoperative relapse were locoregional only in one (2%), distant metastasis only in 16 (33%), and both in three (6%) patients. Conclusions: Better 5-year survival outcomes of CRES 3 T compared to those in the pivotal studies (5-year OS: 56% in JCOG9806 and 44% in SWOG9416/INT0160) indicated that induction therapy using S-1 plus cisplatin and concurrent radical-dose TRT followed by surgery could be a new standard treatment for patients with SST. Clinical trial information: s031180401 .