Paclitaxel plus cisplatin in cancer of unknown primary site (CUP)

Abstract

2123 Cancer of unknown primary site (CUP) consists of a heterogeneous group of tumors that have acquired the capacity to metastasize before the development of a clinically evident primary lesion. They represent about 5–10% of all malignancies. This study was designed to evaluate the efficacy and toxicity of paclitaxel / cisplatin combination chemotherapy in patients with CUP. The rationale for choosing this combination is based on available clinical data that paclitaxel and cisplatin have shown considerable clinical activity in various common malignant tumors including lung, breast, stomach, esophagus, ovary and head/neck cancer. From January 2001 to September 2003, 37 patients with CUP received 21-day cycles of paclitaxel 175 mg/m2 i.v. and cisplatin 60 mg/m2 i.v. on day 1. 31 patients had adenocarcinoma subtypes. The patients received a total of 138 cycles of chemotherapy. The median number of cycles of chemotherapy per patient was 4. The median age of the patients was 53 (range, 21–71) years. The male to female ratio was 1:2.1. Initial presentations were cervical lymphadenopathy, peritoneal carcinomatosis, liver mass, pelvic mass, metastatic bone tumor and pleural effusion. Of these patients, 36 patients were evaluable for efficacy and toxicity. Of the evaluable and measurable 26 patients, complete response was in 1 patient, and partial response was in 10 patients. The overall response rate was 42% (95% C.I., 23–61%). Stable disease was seen in 6 patients, progressive disease in 9 patients. Median time to progression was 4 (95% C.I., 1.3–6.8) months. Median overall survival was 11 (95% C.I., 8.3–13.5) months. No prognostic factor was identified in univariate analysis. However, patients with good performance status and patients with normal CEA level showed marginal progression-free survival benefits (good PS vs poor PS; 5.2 vs 2.7 months, p=0.065) (normal CEA vs abnormal CEA; 5.2 vs 1.9 months, p=0.066). The major toxicities were neuropathy and neutropenia. Grade 4 neutropenia occurred in 10 cases, but febrile neutropenia was seen in 4 cases. Our data suggests that this paclitaxel/cisplatin combination regimen is well tolerated with an encouraging level of activity for patients with CUP. No significant financial relationships to disclose.