Phase II Trial of Paclitaxel, Carboplatin, and Etoposide in Advanced Poorly Differentiated Neuroendocrine Carcinoma: A Minnie Pearl Cancer Research Network Study

Abstract

Purpose To evaluate the efficacy of chemotherapy with paclitaxel, carboplatin, and etoposide in advanced adult poorly differentiated neuroendocrine carcinomas. Patients and Methods Patients eligible for this multicenter, phase II trial had metastatic poorly differentiated neuroendocrine carcinoma and had received no previous treatment. Patients with a variety of known primary sites (excepting small-cell lung cancer) and patients with unknown primary site were eligible. Patients received four courses of chemotherapy with paclitaxel, carboplatin, and etoposide, administered at 3-week intervals. After completing four courses of treatment, patients with objective response or stable disease received three courses (24 weeks) of weekly paclitaxel. Results Seventy-eight patients were treated; 62% had unknown primary site. Forty-one patients (53%) had major responses (complete response rate, 15%), and five patients remain disease free from 18 to 66 months after therapy. Response rates were similar regardless of histology (small-cell v poorly differentiated carcinoma) or primary site. The median, 2-year, and 3-year survivals for the entire group were 14.5 months, 33%, and 24%, respectively. Myelosuppression was the major toxicity, as has been reported previously with this regimen. Conclusion This prospective phase II trial provides additional evidence that this family of relatively uncommon carcinomas is initially chemosensitive, with a high overall response rate to combination chemotherapy and a minority of complete responses. The three-drug regimen evaluated in this trial is moderately toxic, and has no obvious efficacy advantages when compared with standard platinum/etoposide regimens. Treatment for advanced poorly differentiated neuroendocrine carcinoma should parallel treatments used for small-cell lung cancer.