Phase II Clinical Trial of De-Intensified Therapy in Human Papilloma Virus (HPV) Associated Oropharyngeal Squamous Cell Carcinoma

Inclusion criteria

• Histologically confirmed or suspected HPV associated squamous cell carcinoma of the oropharynx.
• p16 immunohistochemistry is the surrogate marker for HPV positivity and will be scored as positive if there is strong and diffuse nuclear and cytoplasmic staining present in greater than 70% of the tumor specimen. (A negative result excludes the patient from the trial)
• In the case of equivocal p16, High Risk HPV (HR HPV), In-Situ Hybridization (ISH) / Polymerase Chain Reaction (PCR) may be performed to determine HPV positivity
• AJCC TNM 7th edition stage T1-T3, N0-N2b (or AJCC TNM 8th edition stage T1-T3 N0-N1) disease.
• Staging will be based on cross sectional imaging investigations and clinical exam.
• Patients who initially have an unknown primary but subsequently have a primary site identified on pathology after surgical resection may be included in the study.
• Multidisciplinary team decision to treat with primary transoral resection and neck dissection.
• Patients considered fit for surgery and adjuvant therapy.
• Aged 18 or over.
• Written informed consent provided.

Exclusion criteria

• HPV negative squamous cell carcinomas of the head and neck
• T4 and/or T1-T3 tumors where transoral surgery is considered not feasible or there is a high likelihood of positive margins.
• AJCC TNM 7th edition N2c-N3 nodal disease (or AJCC TNM 8th edition N2-N3 nodal disease) or high likelihood of gross extranodal extension.
• Patients for whom transoral surgery and neck dissection is not considered the primary treatment modality.
• Distant metastatic disease as determined by routine pre-operative staging radiological investigations e.g. CT thorax and upper abdomen or PET CT.
• Women who are pregnant or breastfeeding
• Prior history of radiation to head and neck