Five-year outcomes of an oropharynx-directed treatment approach for unknown primary of the head and neck.

PURPOSE: Squamous cell carcinoma of unknown primary (SCCHNUP) is commonly treated with comprehensive radiation to the laryngopharynx and bilateral necks. In 1998, we established a departmental policy to treat SCCHNUP with radiation directed to the oropharynx and bilateral neck.

METHODS

From 1998-2011, 60 patients were treated - N1: 18%, N2: 75% and N3: 7%. 82% underwent neck dissection. 55% received IMRT and 62% underwent concurrent chemoradiotherapy.

RESULTS

At median follow-up of 54months, 5 patients failed regionally and 4 emerged with a primary (tongue base, hypopharynx and thoracic esophagus). Five-year rates of regional control, primary emergence, distant metastasis, disease-free survival and overall survival were 90%, 10%, 20%, 72% and 79%, respectively. The 5year rate of primary emergence in a non-oropharynx site was 3%.

CONCLUSION

This is the first demonstration that an oropharynx-directed approach yields low rates of primary emergence in SCCHNUP with excellent oncologic outcomes.