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

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.