[Carcinoma of unknown primary site. Apropos of 100 patients treated at the Montpellier regional center of cancer prevention].

PURPOSE: Carcinomas of unknown primary site are frequent neoplasms which raise diagnostic and therapeutic problems in clinical practice.

METHODS: Clinical records of 100 patients with carcinoma of unknown primary site whose clinical management took place at the Centre Regional de Lutte Contre le Cancer de Montpellier were retrospectively reviewed. Initial clinical and biological characteristics, pre-treatment evaluation, therapies and outcome were recorded.

RESULTS: Three main histological types were observed: adenocarcinoma (66 patients), poorly differentiated carcinoma (19 patients), epidermoid carcinoma (11 patients). Bone, lung, lymph nodes and liver were the most frequently involved metastatic sites. Analysis of the investigations aimed at identifying the primary site (none of which being positive) showed 68 different combinations in 100 patients. Anemia (< 100 g/L) was observed in 10 patients, while serum alkaline phosphatase was increased in 42 patients. Seven patients died before any therapy. Chemotherapy or radiotherapy was advocated in 70 and 59 patients, respectively. Thirty-six patients had concomitant chemoradiotherapy. Chemotherapy included a platinum derivative in 53 patients. The median number of cycles was four. Nine objective responses were observed, six of which occurred in patients who were receiving platinum-based chemotherapy. Ninety-six deaths were encountered, 95 due to the disease progress and one due to an intercurrent cause. The median survival was 9 months. Univariate analysis identified two prognostic factors: the number of metastatic sites and the serum alkaline phosphatase.

CONCLUSIONS: This retrospective study confirms the difficulties in the management of patients with carcinomas of unknown primary site. A literature review suggests limited diagnostic investigations in clinical practice with the aim of identifying tumors of potential prognostic (breast and ovary) or therapeutic (prostate) value. Apart from specific subgroups of patients for whom specific therapy is recommended, there is no current standard chemotherapy.