Comparison of efficacy for postoperative chemotherapy and concurrent radiochemotherapy in patients with IIIA-pN2 non-small cell lung cancer: an early closed randomized controlled trial

Abstract

Objective: The efficacy of postoperative concurrent radiochemotherapy (POCRT) on IIIA-pN2 non-small cell lung cancer (NSCLC) is still unclear. The aim of this randomized controlled trial was to compare POCRT with postoperative chemotherapy (POCT) alone in terms of survival and relapse patterns.

Methods: Patients with completely resected IIIA-pN2 NSCLC were randomized into POCRT or POCT groups. Chemotherapy consisted of paclitaxel (175 mg/m(2)) and cisplatin (60 mg/m(2)) administered intravenously for four cycles on day 1, 22, 43, and 64. Patients in the POCRT group received radiotherapy (50.4 Gy/28 fractions) concurrently with the first 2 cycles of chemotherapy.

Results: This study recruited 140 participants and was closed early because of slow accrual. Data were analyzed for 135 of them including 66 cases in the POCRT group and 69 cases in the POCT group. Patients were followed-up for a median period of 45 months. The POCRT group had a median survival (MS) of 40 months and a 5-year overall survival (OS) rate of 37.9%. The POCT group had a MS of 28 months and a 5-year OS rate of 27.5%. The hazard ratio for death in the POCRT group was 0.69 (95% CI: 0.457-1.044, P=0.073). We observed a disease-free survival (DFS) of 28 months and a 5-year DFS rate of 30.3% in the POCRT group. Likewise, we observed a DFS of 18 months and a 5-year DFS rate of 18.8% in the POCT group. The recurrence hazard ratio in the POCT group was 1.49 (95% CI: 1.008-2.204, P=0.041). Subgroup analysis revealed that POCRT significantly increased the OS rate of the patients with ≥2 pN2 lymph nodes (P=0.021). The POCRT group had a significantly lower local relapse (P=0.009) and distant metastasis (P=0.05) rates as compared to that of the POCT group. One case died of pyemia and 9 cases suffered from grade 3 and 4 acute radiation esophagitis. The two groups had similar and tolerable hematologic toxicities.

Conclusions: Compared with POCT, POCRT increased both local/regional and distant DFS rate of the patients with IIIA-pN2 NSCLC, but not the OS rate. Considering the relatively small sample size of the current study, caution should be taken when adopting the conclusions.

Keywords: IIIA-pN2; Non-small cell lung cancer; Postoperative concurrent radiochemotherapy; Surgery; Survival.