Adenocarcinoma of unknown primary origin: impact of chemotherapy on survival.

Seventy-seven cases of adenocarcinoma of unknown origin were studied retrospectively. Pain was the most common presenting symptom and lymphadenopathy was the most common finding on physical examination. Tumor involved several organs in two thirds of the patients, the lung being the most frequently involved. Complete surgical resection was possible in only four of 27 patients with single organ involvement. All four patients had lymph node dissections and remain free of disease after one to three years. Four patients with tumor confined to the liver received infusion of antitumor agents through the hepatic artery which resulted in objective tumor regression in all, and regression of greater than 50% in two. Forty-three trials of systemic intravenous chemotherapy were administered to 38 patients with nonresectable tumor resulting in greater than 50% tumor regression in eight. Responses were more frequent with regimens containing adriamycin plus either cyclophosphamide or cis-platinum. Median survival of all patients in the study was 31 weeks. Patients who received chemotherapy survived significantly longer (median 41 vs 26 weeks, P = 0.005). Similarly, patients who responded to chemotherapy survived significantly longer than nonresponders (median 54 vs 27 weeks, P less than 0.02). Our results indicate that early treatment of patients with adenocarcinoma of unknown origin improves their prognosis.