A pilot-study of Paclitaxel in previously treated patients with metastatic unknown primary carcinomas

We enrolled 12 patients in a pilot phase II study to evaluate the efficacy and toxicity of paclitaxel as a single agent in the salvage treatment of patients with metastatic unknown primary carcinoma (UPC). Patients were given 175 mg/m(2) of paclitaxel as a three-hour infusion. One patient was enrolled into the study with a diagnosis of poorly differentiated carcinoma but was found after another biopsy to have a soft tissue sarcoma and was therefore not included in this study. All patients had progressive disease after receiving at least one prior chemotherapy regimen containing cisplatin. Two patients had also received radiation therapy. Seven patients had adenocarcinomas, two patients had poorly differentiated adenocarcinomas and two had poorly differentiated carcinomas (PDC). Four patients experienced grade IV granulocytopenia and two patients experienced grade II nausea and vomiting. No responses were observed, and the study was terminated without enrolling more patients. At the dose level used in this study, paclitaxel was inactive in the treatment of patients with UPC whose cancer was resistant to cisplatin.