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/etoposidecontinuous infusion chemotherapy for cancer of unknown primary site inTaiwan, a region with a high prevalence of endemic viral infections.METHOD: Between April 1994 and February 1996, 20 patients with a diagnosisof CUPS were treated, including 15 males and five females, of average age63.3 years (range 41-83 years). Continuous intravenous infusion ofetoposide 80 mg/m2 and cisplatin 25 mg/m2 was given for 3 days every 3weeks. Pretreatment tumor marker and viral serology studies were performedfor baseline evaluation. Nearly two-thirds of the patients had poorlydifferentiated carcinoma. The average number of metastatic sites was 2.65(range 1-4), with liver and lymph node involvement predominating. RESULTS:The overall response rate was 25% (95% CI 17.7-32.3%); 30.7% for poorlydifferentiated cancers and 25% for well differentiated cancers. Mediansurvival was 4 months (range 1-12 months), 4.8 months for patientsattaining partial response. Toxicity was moderate, grade 3 and 4neutropenia occurred in 55% and grade 3 and 4 thrombocytopenia in 40%;other toxicities were mild. CA125 and CA199 were elevated in more than 50%of patients. Viral serology studies were not significantly different fromthose of the indigenous population. CONCLUSION: Etoposide and cisplatincombination chemotherapy has modest activity in patients with extensiveCUPS and, at the schedule and dosage given, it is associated with moderatetoxicity.