Carcinoma of unknown primary site - Long term follow-up after treatment with paclitaxel, carboplatin, and etoposide

BACKGROUND. The long term survival and toxicity associated with the chemoth erapy combination of paclitaxel, carboplatin, and extended-schedule etoposi de used for the treatment of patients with metastatic carcinoma of unknown primary site were evaluated. METHODS. Seventy-one patients were treated between March 1995 and November 1996 with paclitaxel, carboplatin, and oral etoposide every 21 days. Stable or responding patients received four to eight courses of therapy. The foll owing histologies were represented: well differentiated adenocarcinoma (34 patients); poorly differentiated adenocarcinoma or poorly differentiated ca rcinoma (30 patients); poorly differentiated neuroendocrine carcinoma (6 pa tients); and squamous cell carcinoma (1 patient). RESULTS. Forty-eight percent of assessable patients had major responses to therapy (95% confidence interval, 39%-55%), and 10 patients (15%) had compl ete responses. There were no response differences among the major histologi c types. The median survival for all 71 patients was 11 months, and the 1-y ear, 2-year, and 3-year survival rates were 48%, 20%, and 14%, respectively . The minimum followup period was 34 months (range, 34-50 mos). The regimen was tolerated well with no treatment-related deaths and only 12 hospitaliz ations for neutropenia and fever. There was no serious long term toxicity. CONCLUSIONS, In this large Phase II trial, the combination of paclitaxel, c arboplatin, and oral etoposide produced major responses or stable disease s tatus in nearly 80% of patients who had carcinoma of unknown primary site. The median survival and 1-year, 2-year, and 5-year survival rates were note worthy. The current study obtained similar or superior results to those see n with chemotherapy for many other groups of patients, such as those who ha d well defined advanced malignancies, those who were considered to have res ponsive tumors, and those who had obtained substantial benefits from cytoto xic therapy. Although the regimen reported in the current study can become an attractive option for many patients with carcinoma of unknown primary si te, there remains a need for further clinical trials. Cancer 2000;89:2655-6 0. (C) 2000 American Cancer Society.