Neck lymph node metastases from an unknown primary tumor retrospective study and review of literature.

Background and Purpose: Up to 10% of all neck lymph node metastases present without a known primary site. The optimal treatment strategy for these patients is still undefined. The purpose of this retrospective analysis is to assess the outcome in patients with neck metastases from an unknown primary tumor (CUP). Furthermore, prognostic factors and treatment modalities are discussed.
Patients and Methods: From 1984 to 2003, 28 patients with squamous cell neck metastases from a CUP were treated at the authors' institution. In 17 patients, neck dissection (twelve radical, five modified radical) was performed. In that case, adjuvant radiotherapy was carried out with a mean of 56.7 Gy. In eleven patients, only biopsies were done. These patients received definitive radiotherapy with a mean of 66.8 Gy. In summary, 25 patients received extended radiotherapy including both sides of the neck and potential mucosal primary sites. Additional chemotherapy was administered to five patients.
Results: The duration of follow-up was 4.1-189.5 months (median 45.1 months). After this period of time, ten patients (36%) remained alive. 5-year overall survival was 40.1%, neck control rate 72.7%. No subsequent primary could be detected. Extracapsular extension and surgery had significant influence on prognosis. Grade 3 toxicity (mucositis or skin reactions) was seen in three patients; no hematologic toxicity > grade 2 was observed. 19 patients suffered from grade 2 xerostomia.
Conclusion: With radical surgery followed by radiotherapy good survival rates in patients with neck metastases from a CUP can be obtained. Whether limited radiotherapy might be equal to extended irradiation and can reduce side effects, must be shown in ongoing clinical trials.