CONTINUOUS-INFUSION CISPLATIN AND ETOPOSIDE CHEMOTHERAPY FOR CANCER OF UNKNOWN PRIMARY SITE (CUPS) IN TAIWAN, A REGION WITH A HIGH PREVALENCE OF ENDEMIC VIRAL-INFECTIONS

Background: To evaluate the efficacy and toxicity of cisplatin/etoposi de continuous infusion chemotherapy for cancer of unknown primary site in Taiwan, a region with a high prevalence of endemic viral infection s. Method: Between April 1994 and February 1996, 20 patients with a di agnosis of CUPS were treated, including 15 males and five females, of average age 63.3 years (range 41-83 years). Continuous intravenous inf usion of etoposide 80 mg/m(2) and cisplatin 25 mg/m(2) was given for 3 days every 3 weeks. Pretreatment tumor marker and viral serology stud ies were performed for baseline evaluation. Nearly two-thirds of the p atients had poorly differentiated carcinoma. The average number of met astatic sites was 2.65 (range 1-4), with liver and lymph node involvem ent predominating. Results: The overall response rate was 25% (95% CI 17.7-32.3%); 30.7% for poorly differentiated cancers and 25% for well differentiated cancers. Median survival was 4 months (range 1-12 month s), 4.8 months for patients attaining partial response. Toxicity was m oderate, grade 3 and 4 neutropenia occurred in 55% and grade 3 and 4 t hrombocytopenia in 40%; other toxicities were mild. CA125 and CA199 we re elevated in more than 50% of patients. Viral serology studies were not significantly different from those of the indigenous population. C onclusion: Etoposide and cisplatin combination chemotherapy has modest activity in patients with extensive CUPS and, at the schedule and dos age given, it is associated with moderate toxicity.