Squamous cell carcinoma from an unknown head and neck primary site: a "selective treatment" approach.

OBJECTIVE To assess the efficacy of limiting treatment to the involved neck by way of neck dissection and adjuvant radiotherapy and reserving other therapies for salvage in the management of metastatic cervical squamous cell carcinoma from an unknown head and neck primary site. DESIGN Retrospective study of patients whose clinicopathological data had been prospectively collected in a comprehensive head and neck database. SETTING A tertiary referral university hospital. PATIENTS The study population comprised 70 patients with metastatic cervical squamous cell carcinoma from an unknown head and neck primary site. INTERVENTIONS Neck dissection alone in patients with pN1 disease confined to the lymph node. All remaining patients received neck dissection and adjuvant postoperative irradiation of the involved (dissected) neck. MAIN OUTCOME MEASURES Incidence of primary, regional, and distant recurrence and disease-specific and overall survival. RESULTS Nodal stage was pN1 in 5 patients (7%); pN2a in 13 (19%); pN2b in 30 (43%); pN2c in 4 (6%); and pN3 in 18 (26%). Neck dissection alone was performed in 10 patients (14%), while 60 patients (86%) underwent neck dissection and adjuvant irradiation. Median follow-up was 45 months. The primary tumor site emerged in 8 patients (11%). The 5-year control rates were 84% in the ipsilateral (dissected) neck and 93% in the contralateral (undissected) neck. The 5-year disease-specific and overall survival rates were 62% and 56%, respectively. Macroscopic extracapsular spread was the only statistically significant adverse prognostic factor (P < .001). CONCLUSIONS The results of our selective treatment approach compare favorably with the results of other reported protocols using comprehensive irradiation or concurrent chemoradiation. However, patients with extracapsular spread and pN2 or pN3 disease were at high risk of treatment failure and may benefit from adjuvant chemoradiation. Although our protocol spares patients of potentially morbid therapies, salvage is rarely successful.