Docetaxel and carboplatin combination chemotherapy as outpatient palliative therapy in carcinoma of unknown primary: a multicentre Hellenic Cooperative Oncology Group phase II study.

INTRODUCTION: Taxane/platinum combinations exhibit synergistic cytotoxicity and activity against a broad range of solid tumours. We sought to optimise the regimen as a suitable outpatient palliative treatment for cancer of unknown primary (CUP). PATIENTS AND METHODS: Eligible CUP patients with adenocarcinoma or poorly differentiated carcinoma, performance status of 0-2, adequate organ function and assessable disease were treated with docetaxel 75 mg/m(2) and carboplatin at an area under the concentration time-curve (AUC) of 5, both as 30-minute intravenous infusions, every three weeks. Patients with isolated axillary adenopathy, squamous cell cervical or inguinal adenopathy and PSA or germ-cell serum tumour markers were excluded.
RESULTS: Forty-seven patients entered the trial, 24 with predominantly nodal disease or non-mucinous peritoneal carcinomatosis (favourable risk) and 23 with visceral metastases (unfavourable risk). A median of 6 cycles of chemotherapy were administered, with relative dose intensities of both drugs >90%. Response rates were 32% (46% in favourable risk, 17% in unfavourable), comparable to the activity of paclitaxel/platinum regimes, though complete remissions were seen only in favourable risk patients. Granulocyte-colony stimulating factor support was used in a third of treatment cycles. Toxicity was mild and manageable, with grade 3-4 neutropenia in 26% of patients, febrile neutropenia in 7% and severe non-hematologic side-effects in less than 8% of patients. No toxic deaths or severe neurotoxicity were seen. Median time to progression (TTP) and overall survival (OS) were 5.5 and 16.2 months respectively. Survival was driven mainly by favourable-risk patients (22.6 months), as those with visceral metastases had a poor median survival of only 5.3 months. Good performance status and low-volume disease predicted for superior outcome, while docetaxel relative dose-intensity was a positive prognosticator only in favourable-risk patients.
CONCLUSIONS: One-hour docetaxel/carboplatin is a convenient, safe and effective outpatient palliative treatment for CUP patients, providing meaningful survival prolongation only in favourable-risk patients. Insights in the molecular biology of CUP are needed for the development of targeted therapeutic manipulations of malignant resistance and progression.