Inclusion Criteria:

- American Joint Committee on Cancer (AJCC) TNM Stage III-IVa (T3N0-T4N0, and
T1N1-T4N3) oropharyngeal squamous cell carcinoma (SCC) tumours

- Clinical multidisciplinary team decision to treat with primary curative cisplatin
chemoradiotherapy

- No previous treatment including surgery, except node biopsies or diagnostic
tonsillectomy

- Medically fit (ECOG 0, 1 or 2)

- Adequate cardiovascular, haematological, renal and hepatic function

- Age > 18 years

- Written informed consent given

- Using adequate contraception [male and female participants]. Must take contraceptive
measures during, and for at least three months after treatment.

Exclusion Criteria:

- Distant metastasis (i.e. AJCC TNM stage IVc disease)

- AJCC TNM Stage T1-2N0 disease

- Treated with primary radical surgery to the primary site (e.g. resection)

- Concurrent use of CYP3A4 inducers or inhibitors. [A standard course of dexamethasone
or aprepitant for the prevention of cisplatin-induced nausea and vomiting is
permitted]

- Serious cardiac illness or other medical conditions precluding the use of cisplatin
or cetuximab [no history of clinically significant cardiac disease, serious
arrhythmias, or significant conduction abnormalities; no uncontrolled seizure
disorder; no active neurologic disease; no neuropathy greater than grade 1]

- Patients who have p16+ tumours who also have N2b, N2c or N3 nodal disease and whose
lifetime smoking history is also more than 10 pack years (i.e. have both risk
factors).

- Pregnant or lactating

- Previous treatment for any other cancer with cytotoxics, radiotherapy or anti-EGFR
therapies

- Inadequate renal, haematological or liver functions [Absolute neutrophil count
<1,500/mm3; platelet count <100,000/mm3; WBC <3,000/mm3; haemoglobin <9 g/dL.
[Haemoglobin correction by transfusion permitted.] Bilirubin > 1.5 times upper limit
of normal (ULN); alkaline phosphatase > 2.5 times ULN; AST and ALT > 2.5 times ULN.
Creatinine > 1.5 mg/dL; Creatinine clearance < 60 mL/min]

- Patients with clinically significant hearing impairment

- Life expectancy less than 3 months

- Other malignancy within the past 3 years except basal cell skin cancer or
pre-invasive carcinoma of the cervix.