A phase II study of carboplatin and paclitaxel in adenocarcinoma of unknown primary

Background: Cisplatin-based combination chemotherapy is commonly used in the treatment of carcinoma of unknown primary site. Paclitaxel has shown promising activity as a single agent in a number of malignancies. This study was conducted to evaluate the efficacy and toxicity of combination carboplatin and paclitaxel in patients with adenocarcinoma of unknown primary site (ACUP). Methods: Twenty-two patients with ACUP were enrolled in the study. Patients were treated with 200 mg/m(2) paclitaxel intravenously (IV) over 3 hours followed by carboplatin IV with a targeted plasma area under the curve (AUC) of 5 mg/h/mL. Results: A total of 73 treatment courses were administered with a median of 5 courses per patient. Five of the 22 registered patients had a major response for an objective response rate of 23% (90% confidence interval [CI], 0.11-0.40) by intention-to-treat analysis. The median response duration was 4.1 months (90% CI, 3.6-7.1). The median survival time was 6.5 months (90% CI, 5.5-10.1) and the 1-year survival rate was 27% (90% CI, 0.11-0.42). The major toxicity observed was neutropenia, with grade 3-4 neutropenia occurring in 3 patients (14%). There were no treatment-related deaths. Conclusions: The combination of carboplatin and paclitaxel is a tolerable and moderately active regimen in ACUP.