O3–088 - Additional Analysis of WJTOG0105 Comparing Second and Third-Generation Regimens with TRT in Unresectable Stage III NSCLC

Abstract

Background: The WJTOG0105 study was conducted to compare third-generation regimen (irinotecan/carboplatin [IC], paclitaxel/carboplatin [PC]) and second-generation regimen (mitomycin/vindesine/cisplatin [MVP]) with concurrent thoracic radiotherapy (TRT) in patients with unresectable stage III non-small-cell lung cancer (J Clin Oncol. 2010; 28: 3739-45). We conducted an additional analysis by the histological type (Squamous [Sq] vs. Non-squamous [Non-sq]) to closely examine differences of efficacy between more frequent radiosensitizing doses and systemic doses of chemotherapy. Materials and Methods: Patients received the following treatments: MVP, mitomycin (8 mg/m2 on day 1, 29), vindesine (3 mg/m2 on day 1, 8, 29, 36), and cisplatin (80 mg/m2 on day 1, 29) with concurrent TRT (60 Gy), followed by 2 courses of MVP; IC, weekly irinotecan (20 mg/m2)/carboplatin (AUC 2) for 6 weeks with concurrent TRT (60 Gy), followed by 2 courses of irinotecan (50 mg/m2)/carboplatin (AUC 5); PC, weekly paclitaxel (40 mg/m2)/carboplatin (AUC 2) for 6 weeks with concurrent TRT (60 Gy), followed by 2 courses of paclitaxel (200 mg/m2)/carboplatin (AUC 5). Overall survival (OS), progression free survival (PFS), and patterns of initial failure were compared by the histological type. Results: The median OS and PFS were 20.3, 9.0 months in Sq and 20.5, 8.1 months in Non-sq. The Hazard ratio (HR) for OS and PFS in Non-sq were 0.996 (P = 0.973) and 1.199 (P = 0.079). Although there was no statistically significant difference between Sq and Non-sq, the out-field recurrence rate in Non-sq (51.1%) was higher than Sq (26.1%) and the PFS in Sq tended to be longer than Non-sq. The efficacy of PC was compared with MVP in each histological type. For Sq, the median OS and PFS were 22.0, 10.4 months in PC and 19.7, 9.3 months in MVP. The HR for OS and PFS in PC were 0.957 (P = 0.822) and 0.871 (P = 0.459). For Non-sq, the median OS and PFS were 21.3, 8.1 months in PC and 21.8, 7.6 months in MVP. The HR for OS and PFS in PC were 1.083 (P = 0.662) and 0.996 (P = 0.984). Therefore no statistically significant difference was found between PC and MVP in each histological type. Furthermore, the patterns of initial failure were similar between PC and MVP. Conclusions: Weekly PC with concurrent TRT showed similar efficacy to MVP with concurrent TRT, with no relation to the histological type.