A multicenter prospective study of carboplatin and paclitaxel for advanced thymic carcinoma: West Japan Oncology Group 4207L.

Abstract

7529 Background: Thymic carcinoma (TC) is a rare malignant tumor originated within the thymus gland and is associated with a poor prognosis, differing from thymoma which is the most common type of thymic malignant neoplasm. No results of clinical trials focusing on TC have been reported. This single-arm study evaluated carboplatin and paclitaxel (CbP) in previously untreated patients (pts) with advanced TC. Methods: Pts with Masaoka’s stage III to IVb TC, ECOG PS 0 to 1, and more than 20 years old were eligible. The study treatment consisted of carboplatin (AUC 6) and paclitaxel (200 mg/m2) every 3 weeks for a maximum of 6 cycles. The primary endpoint was objective response rate (ORR) by extramural assessment. Secondary endpoints included overall survival (OS), progression-free survival (PFS), and safety. All pts were followed-up until 24 months (mo) after last enrollment. Based on the SWOG 2-stage design, the planned sample size of 40 pts was determined to reject the ORR of 20% under the expectation of 40% with a power of 0.85 and a type I error of 0.05. Results: From May 2008 to November 2010, 40 pts were enrolled from 21 centers. Of 39 evaluable for analysis, the median age was 62 years (range, 36–84); 23/16 males/females; 3/10/26 with Masaoka’s stage III/IVa/IVb; 9/11/19 with squamous cell carcinoma/poorly differentiated neuroendocrine carcinoma/other types. The median number of cycles was 6. There was 1/13 complete/partial responses with an ORR of 36% (95% confidence interval [CI], 21-53%; P = 0.031). The median PFS was 8.1 mo (5.4-13.1 mo) while OS did not reach the median value. The 1-year and 2-year survival rates were 85% (95% CI, 69-93%) and 71% (95% CI, 54-83%), respectively. Major adverse event was grade 3-4 neutropenia in 34 pts (87%). Two cases (5%) of grade 3 febrile neutropenia, neuropathy, and arthralgia were observed, respectively. There was no treatment-related death. Conclusions: CbP showed higher efficacy in advanced TC as compared with anthracycline-based chemotherapy which is the current standard for the treatment of thymoma. Our results established that CbP, one of the standard treatments for non-small cell lung cancer, also serves as a key chemotherapy regimen for TC. Clinical trial information: UMIN000001358.