A Phase II Clinical Trial of Neoadjuvant Concurrent Chemoradiotherapy for Locally Advanced High-Grade Thymic Tumors.

INTRODUCTION

Optimal management of locally advanced thymic tumors remains controversial. We conducted a clinical trial (ChiCTR-TNC-10001204) to investigate the safety and efficacy of neoadjuvant concurrent chemoradiotherapy in patients with locally advanced thymic tumors.

METHODS

The trial was conducted at the Shanghai Chest Hospital in patients with potentially unresectable high-grade thymic tumors. Induction consisted of chemotherapy (docetaxel and cisplatin) and concurrent radiation (40 Gy). The primary end point was objective response rate (ORR).

RESULTS

A total of 33 patients were accrued, including 11 with thymomas, 20 with thymic carcinomas, and two with neuroendocrine thymic tumors. ORR was 48.5%, with 16 patients having partial response. The other 17 had stable disease (SD). Thymomas had higher ORR (63.6%) than carcinomas (40.9%). A total of 13 patients (39.4%) experienced grades 3 to 4 toxicity. Surgical resection was feasible after induction in 23 patients (69.7%), among which 19 (82.6%) had complete resection. A higher rate of surgery (87.5% versus 52.9%,  = 0.057) and a significantly higher rate of R0 resection rate (81.3% versus 35.3%,  = 0.024) were observed in patients with partial response than in those with SD. Five-year overall survival and progression-free survival for the whole group were 63.5% and 44.9%, respectively. Patients with thymomas had significantly higher 5-year progression-free survival than the others (81.8% versus 25.6%,  = 0.012). Cumulative incidence of progression was significantly lower in patients with surgery than in those without (5-y CIP: 38.2% versus 80.0%,  = 0.045).

CONCLUSIONS

Neoadjuvant concurrent chemoradiotherapy is well tolerated and effective for patients with potentially unresectable high-grade thymic tumors, especially for patients with thymomas. Effective induction chemoradiation may help increase the chance of surgical resection and prolonged disease control. Future studies are in need to find more effective treatment approaches for patients with thymic carcinomas.