Carcinoma of an unknown primary site: A chemotherapy strategy based on histological differentiation - results of a prospective study

Background: To evaluate the efficacy and toxicity of a chemotherapy strateg y based on histological differentiation, for patients with carcinoma of unk nown primary site. Patients and methods: Forty-eight patients were prospectively included in t he trial. Thirty patients with poorly-differentiated carcinoma or poorly-di fferentiated adenocarcinoma (group A) received a combination of cisplatin a nd etoposide. Patients with a responsive or stable disease after two cycles received the same regimen plus bleomycin, ifosfamide and G-CSF. Eighteen p atients with well- or moderately-differentiated carcinoma (group B) receive d cisplatin, continuous infusion 5-fluorouracil (5-FU) and alpha -interfero n. Treatment was maintained in case of response or stable disease for up to six cycles. Results: The overall response rate (RR) for the entire group is 43% (95% co nfidence interval (CI): 35.9%-50.1%): seven CR and five PR in group A (RR = 40%) and six CR and two PR in group B (RR = 44%). Grade 4 leucopenia was o bserved in 22 (46%) patients and sepsis in 3 (6%). Median survival is 9.4 m onths (range 5-13.7 months) and 16.1 months (range 11.8-20.3 months), respe ctively. Conclusions: This chemotherapy strategy is one way to achieve high response rates, particularly for patients with well- or moderately-differentiated a denocarcinoma usually considered poorly chemosensitive.