Phase II study of docetaxel (T), carboplatin (C), and gemcitabine (G), in advanced tumors of unknown primary site

Abstract

12028 Background: Treatment of tumors of unknown primary site is still a challenge nowadays. D, C and G have shown high activity in solid tumors. We designed this study to evaluate activity and toxicity profile of a combination of these three drugs, according a protocol previously tested in lung cancer (Pectasides D, et al. J Clin Oncol 1999). Methods: Patients with histological diagnosis of solid tumor of unknown primary site, age ≥ 18 years old, ECOG PS ≤ 2 and adequate bone marrow, renal, hepatic and cardiac functions, were included. Treatment consisted in (d1): C AUC = 5 and G 800 mg/m2 IV; and d8): D 75 mg/m2 and G 800 mg/m2 IV, with G-CSF support. Courses were repeated every 28d for a maximum of 8 cycles, unless progression, unacceptable toxicity or consent withdrawal, whichever comes first. Results: Sixty-three patients have been included: median age was 66 years old (28–90), 89.6% of patients had ECOG PS 0–1. Tumor histology included adenocarcinoma (65.1%), undifferentiated (17.5%) and carcinoma (7.9%) or large-cell carcinoma (1.6%). Main metastatic sites were lung (49%), liver (44%), lymph nodes (41%) and bone (25%). Previous treatments included surgery (20.6%), chemotherapy (1.6%) and radiotherapy (12.7%). Treatment: 296 cycles (median 6, range 1–11) were administered. Median relative dose intensity was 96% for D, C and G. Efficacy: 8 patients achieved CR and 15 PR, resulting in an overall response rate of 36.5% (95% CI: 24.6–48.4%). Main grade III/IV toxicity per patient were asthenia (19%), diarrhea (18%), mucositis (11%), vomiting (10%), nausea (6%), thrombocytopenia (38%), neutropenia (24%), leucopenia (19%) and anemia (13%). Febrile neutropenia was observed in 2 patients (3%). Fourteen patients (22.2%) experienced severe toxicity: 9 of them were dropped out and 5 were toxic deaths (2 sepses, 2 pancytopenia and 1 pulmonary thromboembolism). Median time to treatment failure was 6.0 months (95% CI: 4.8–7.1), median TTP was 10.8 months (95% CI: 8.6–13.0) and median OS was 11.8 months (95% CI: 9.4–12.3), with a median follow up of 10.8 months. Conclusions: Despite the combination of D, C and G shows high activity in tumors of unknown primary site, its toxic death rate is > 5%. Thus, our group is working no longer with such a triplet combination. No significant financial relationships to disclose.