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

- Squamous cell carcinoma of unknown primary (SCCHNUP) is challenging to treat.
- Treatment often involves comprehensive radiation (RT) to the laryngopharynx & neck.
- We established a policy to treat SCCHNUP with RT to the oropharynx & bilateral neck.
- At median follow-up of 54 months.
- The 5 yr rates of regional control & primary emergence were 90% & 10%, respectively.
- The 5 yr rates of distant metastasis & overall survival were 20% & 79%, respectively.
- The 5 year rate of primary emergence in a non-oropharynx site was 3%.
- Oropharynx-directed RT yields low rates of primary emergence in SCCHNUP.

PurposeSquamous 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.MethodsFrom 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.ResultsAt median follow-up of 54 months, 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 5 year rate of primary emergence in a non-oropharynx site was 3%.ConclusionThis is the first demonstration that an oropharynx-directed approach yields low rates of primary emergence in SCCHNUP with excellent oncologic outcomes.