29 Single network experience of the efficacy of weekly carboplatin and paclitaxel as second line treatment for metastatic thymoma and thymic carcinoma

Abstract

Introduction: Relapsed and pre-treated thymomas and metastatic thymic carcinomas represent a rare sub-group with a poor prognosis for which there is limited evidence to support advanced lines of treatment. The 3-weekly carboplatin and paclitaxel (CP) regimen has shown clinical activity although it yields significant toxicity. Weekly CP was proposed as an alternative for pre-treated patients with potentially less toxicity and possibly greater efficacy. We report outcomes of 4 patients with advanced thymic tumours treated with weekly CP. Methods: We conducted a retrospective review of the efficacy and toxicity profile of weekly carboplatin (AUC2) and paclitaxel (80mg/m2) for metastatic thymoma in the second line setting at 2 cancer centres. Treatment was administered weekly for 3 weeks until disease progression or unacceptable toxicities. Results: We identified 4 patients, 3 female and 1 male, and median age was 59.5 (range 37 70). Histology included 2 Type-B3 thymomas, 1 B1 thymoma and 1 thymic carcinoma. Previous chemotherapy included platinum combinations with either cylopshophomide and adriamycin or etoposide. 1 patient also received radiotherapy followed by erlotinib. The median number of cycles of CP received was 5.5 (range 4 6). 3 partial responses and 1 disease stabilisation were reported, accounting for an overall disease control rate of 100%. Median progression free survival was 5.5 months. 3 patients had grade 3 4 toxicities requiring dose reductions, mainly involving myelosuppression and neuropathy. Treatment was discontinued due to toxicity in 1 patient, due to disease progression in another and due to severe myasthenic crisis in the 3rd. 2 patients had progressive disease shortly after completing chemotherapy. Conclusion: Weekly CP achieved clinical responses in this small group of aggressive thymic tumours with acceptable toxicity. Recently sunitinib has also demonstrated efficacy in patents without C-kit mutations. Further prospective studies are needed to evaluate the efficacy of CP in this pre-treated population and to validate our preliminary observations.