Post-operative Concurrent Chemo-radiotherapy Versus Post-operative Radiotherapy for Cancer of the Head and Neck

Two in every 3 Australians will be affected by skin cancer over their lifetime. The prevalence of skin cancer will continue to increase due to the ageing population and represents a significant problem in our community. Cure of early (T1-2) de novo cutaneous squamous cell carcinoma (CSCC) treated with either curative intent surgery or radiotherapy is 85-100%. However, the cure rate for locally advanced, recurrent, or metastatic disease to regional nodes following surgery alone are much lower, in the order of 20-70%. Metastatic CSCC is the most common malignancy of the parotid region in Australia. The 5 year loco-regional control with surgery alone is in the order of 40%-45%. The addition of post-operative radiotherapy improves loco-regional control by 15-20%, and is therefore considered the standard of care in this group of patients.

Recent data have shown that synchronous post-operative chemo-radiotherapy is superior to post-operative radiotherapy alone in "high-risk" mucosal head and neck squamous cell carcinoma (HNSCC). However, to date, there is no evidence from randomised trials that such a benefit exists in CSCC of the head and neck. At present there is little consensus amongst clinicians in Australia as to who should receive post-operative chemo-radiotherapy in CSCC. Although tumour control rates may be improved, the addition of chemotherapy may also significantly increase treatment related toxicity. Nonetheless, some centres have adopted the use of post-operative chemo-radiotherapy in selected patients with CSCC based on extrapolation from mucosal sites. This has resulted in a wide variability in practice for this disease.

Australia is uniquely placed to perform such a trial comparing post-operative chemo-radiotherapy to post-operative radiotherapy alone in high-risk CSCC due to the high rate of skin cancer. Currently there are limited data to guide management of patients with resected CSCC who are at high risk for recurrence. While it is reasonable to hypothesize that concurrent chemotherapy in this setting will confer a similar benefit to that seen in mucosal HNSCC, this can only be established by a randomized trial as proposed. If the addition of chemotherapy is shown to be beneficial and safe, then these results are likely to be translated into standard practice both nationally and internationally quite rapidly. On the other hand, if the treatment is found to be ineffective then patients will be spared the unnecessary toxicity and inconvenience associated with the addition of chemotherapy. A further important aspect of this trial will be the assessment of patient-related outcomes using a validated quality of life questionnaire. It will be important to ascertain whether any improvement in locoregional control due to the addition of chemotherapy, is also associated with improvement in quality of life compared to the control arm.

Inclusion criteria

• Histologically proven SCC
• Patients have undergone either:

• Resection of the primary lesion
• Any type of parotidectomy (superficial, total, partial, etc.)
• Any type of neck dissection(s)
• High risk feature(s); Advanced primary disease or high risk nodal disease

High Risk Nodal Disease

• Intra-parotid nodal disease (any number or size, with/without extracapsular extension, with/without an identifiable index lesion)
• Cervical nodal disease with a synchronous index lesion or previously resected cutaneous primary tumour (<5 years) within the corresponding nodal drainage and a mucosal primary has been excluded with at least a CT +/- MRI and panendoscopy* *For cervical nodal disease to be eligible there must be at least one of the following criteria:

• > 2 nodes
• largest node > 3 cm
• Extracapsular extension

Advanced Primary Disease (TNM 6th Edition 2002) (Appendix 1)

• T3-4 primary disease (cartilage, skeletal, muscle, bone involvement, > 4 cm) of the head and neck including lip, nose and external auditory canal with or without nodal disease
• In transit metastases (metastases between the primary site and the adjoining nodal basin)

• Age > 18 years
• Written informed consent
• ECOG <= 2
• Absolute neutrophil count > 1.5 X 10^9/L, platelet count > 100 X 10^9/L, and haemoglobin > 10 g/dL (pre-radiotherapy blood transfusion to elevate the haemoglobin > 10 g/dL is permissible)
• Calculated creatinine clearance (Cockcroft-Gault) >= 40 mL/min
• Available for follow-up for up to 5 years
• Life expectancy greater than 6 months

Exclusion criteria

• Intercurrent illness that will interfere with either the chemotherapy or radiotherapy such as immunosuppression due to medication or medical condition
• Metastasis(es) below the clavicles
• Previous radical radiotherapy to the head and neck, excluding treatment of an early glottic cancer greater than or equal to 2 years ago and superficial radiotherapy to cutaneous SCC or Basal cell carcinoma
• High risk for poor compliance with therapy or follow-up as assessed by investigator
• Pregnant or lactating women
• Patients with prior cancers, except: those diagnosed > 5 years ago with no evidence of disease recurrence and clinical expectation of recurrence of less than 5%; or successfully treated Level 1 cutaneous melanomas or early glottic cancer > 2 years ago; or non-melanoma skin cancer; or carcinoma in situ of the cervix.
• Low risk cervical nodal disease* without advanced primary disease

*Low risk cervical nodal disease is defined as the presence of all of the following criteria:

• single nodal metastasis
• greater then or equal to 3cm,
• no extracapsular extension