CARCINOMA OF UNKNOWN PRIMARY SITE - TREATMENT WITH 1-HOUR PACLITAXEL,CARBOPLATIN, AND EXTENDED-SCHEDULE ETOPOSIDE

Purpose: To evaluate the efficacy and toxicity of a novel chemotherapy combination that includes paclitaxel, carboplatin, and extended-sched ule etoposide in the treatment of patients with carcinoma of unknown p rimary tumor site. Patients and Methods: Fifty-five patients with carc inoma of unknown primary tumor site were treated with the following re gimen, administered every 21 days: paclitaxel 200 mg/m(2) by 1-hour in travenous (IV) infusion on day 1, carboplatin at an estimated area und er the concentration-time curve (AUG) of 6.0 on day 1, and etoposide 5 0 mg alternated with 100 mg orally on days 1 through 10. Responding pa tients received a total of four courses of treatment, The following hi stologies were included: adenocarcinoma, 30 patients; poorly different iated carcinoma (PDC) or poorly differentiated adenocarcinoma (PDA), 2 1; poorly differentiated neuroendocrine carcinoma, three; and squamous carcinoma, one, Results: Twenty-five of 53 assessable patients (47%; 95% confidence interval [CI], 33% to 61%) had major objective response s to treatment (seven complete responses). Response rates were similar in patients with adenocarcinoma versus PDC (45% and 48%, respectively ). The actuarial median survival time for the entire group was 13.4 mo nths. The regimen was well tolerated, with only seven hospitalizations for treatment of neutropenia and fever (4% of courses) and no treatme nt-related deaths. Conclusion: The combination of paclitaxel, carbopla tin, and extended-schedule etoposide is highly active and well tolerat ed in patients with carcinoma of unknown primary tumor site. Response rates and survival in this multicenter community-based trial compare f avorably with all previously studied empiric regimens. In addition, th is regimen is substantially less toxic and easier to administer than t he cisplatin-based regimens previously used in this setting. If this l evel of efficacy is confirmed, this treatment should be considered sta ndard first-line therapy in patients with carcinoma of unknown primary tumor site. (C) 1997 by American Society of Clinical Oncology.