Background: Human papillomavirus – associated oropharyngeal squamous cell carcinoma (HPV+ OPC) accounts for nearly 65% of OPC in the US1. HPV+ OPC has a significant survival advantage when compared to HPV-negative OPC2 but both still undergo similar treatments which cause significant comorbidities like dysphagia and disfigurement. These comorbidities are especially prominent in the salvage treatment setting when patients have already failed primary surgery, radiation, chemoradiation or a combination of these. Given HPV+ OPC’s less aggressive phenotype, we hypothesized that a more limited salvage neck dissection in these patients could provide similar oncologic treatment with significantly less morbidity than a comprehensive multi-level neck dissection. In regional metastatic disease that is limited to a single node, superselective neck dissection (SND) has been shown to produce control comparable to that of more extensive neck dissection techniques but with significantly less morbidity3. This project aims to evaluate whether a single level SND in HPV+ OPC patients would be oncologically safe in the pre-operatively staged N1 patient.
Methods: After IRB approval was obtained, we retrospectively reviewed 515 patients from the University of Pittsburgh’s Head and Neck Tumor registry from 2000-2017. Using the electronic medical record, 87 patients met inclusion criteria. These patients all had primary oropharyngeal squamous cell carcinoma with recurrence or a second primary and underwent salvage selective neck dissection. All patients had at least two levels dissected in levels 1-4. Patient demographics, tumor staging, treatment modalities, pathology results, HPV status, survival and imaging type were collected. Sensitivity and positive predictive values of pre-operative staging compared to pathologic staging were calculated.
Results: Eight-seven patients met inclusion criteria and 42 patients were HPV+ (13 were HPV- and 32 were unknown HPV). Sixty of these patients received primary chemoradiation therapy (69%) and eleven (13%) underwent radiation alone. Sixty-seven (77%) patients underwent selective neck dissection instead of modified radical or radical neck dissections. Twenty-nine HPV+ patients had imaging recorded prior to their salvage neck dissection consisting of CT or PET/CT. Twenty-two of these patients were staged at N1 based on imaging and physical exam, On final pathology, six (27%) were downstaged to N0, six (27%) were correctly staged at N1, and ten (45%) were upstaged to an N2 stage. In pre-operatively staged N1 patients, the pre-salvage imaging and physical exam work up yielded sensitivity=37.5% and positive predictive value=50%.
Conclusions: Our aim was to determine the safety of performing SND in patients with recurrent or second primary HPV+ OPC. Forty-five percent of patients pre-operatively staged as N1 were upstaged after multi-level salvage neck dissection. Our data suggest that a comprehensive, multi-level neck dissection should be performed.
1. Plonowska KA, Strohl MP, Wang SJ, et al. Human Papillomavirus-Associated Oropharyngeal Cancer: Patterns of Nodal Disease. Otolaryngol Head Neck Surg. 2018:194599818801907.
2. Maghami E, Koyfman SA, Weiss J. Personalizing Postoperative Treatment of Head and Neck Cancers. Am Soc Clin Oncol Educ Book. 2018(38):515-522.
3. Suarez C, Rodrigo JP, Robbins KT, et al. Superselective neck dissection: rationale, indications, and results. Eur Arch Otorhinolaryngol. 2013;270(11):2815-2821.