Cancer of unknown primary (CUP) of the head and neck: retrospective analysis of 81 patients.

The treatment of patients with cervical lymph node metastases without detectable primary tumor remains an important challenge, until today, no standard therapy is available. The present study investigated the multimodal treatment of patients with head and neck CUP syndrome (HNCUP) and their follow-up retrospectively. 81 patients with cervical lymph node metastases without a primary tumor were treated at the Departments of Otorhinolaryngology as well as Radiotherapy and Radiation Oncology at the University of Saarland in Homburg, Germany in the period between 1991 and 2013. All patients received routine work-up consisting of CUP panendoscopy and imaging. Neck dissection was then performed in 77% of the patients. The most common histology was squamous cell carcinoma (80%). Ten percent of the patients had distant metastases. All patients underwent primary or adjuvant radiation therapy, or simultaneous radiochemotherapy. After a median follow-up of 3.5 years, the 5-year survival rate was 30%. There was a local recurrence that was known in 20/63 patients (31%) and distant metastases were documented in 19/61 M0 patients (31%). Higher grade late toxicity (grade 3-4) was observed in 12% of patients. Neck dissection and radiation therapy remains an integral part of HNCUP therapy, while the use of chemotherapy could be considered in selected cases. Prospective multicenter randomized trials would be necessary to identify the best target volume and to clarify the role of chemotherapy.