Epidermal growth factor receptor targeted therapy in stages III and IV head and neck cancer

What are the benefits associated with the use of anti-epidermal growth factor receptor (anti-EGFR) therapies in squamous cell carcinoma of the head and neck (HNSCC)? Anti-EGFR therapies of interest included cetuximab, gefitinib, lapatinib, zalutumumab, erlotinib, and panitumumab.

Head-and-neck cancer includes malignant tumours arising from a variety of sites in the upper aerodigestive tract. The most common histologic type is squamous cell carcinoma, and most common sites are the oral cavity, the oropharynx, the hypopharynx, and the larynx. Worldwide, HNSCC is the sixth most common neoplasm, and despite advances in therapy, long-term survival in HNSCC patients is poor. Primary surgery followed by chemoradiation, or primary chemoradiation, are the standard treatment options for patients with locally advanced (stages III-IVB) HNSCC; however, meta-analytic data indicate that the benefit of concurrent platinum-based chemotherapy disappears in patients over the age of 70 years. Cetuximab is a monoclonal antibody approved for use in combination with radiation in the treatment of patients with untreated locally advanced HNSCC and as monotherapy for patients with recurrent or metastatic (stage IVC) HNSCC who have progressed on platinum-based therapy. Given the interest in anti-EGFR agents in advanced HNSCC, the Head and Neck Cancer Disease Site Group (DSG) of Cancer Care Ontario's Program in Evidence-Based Care (PEBC) chose to systematically review the literature pertaining to this topic so as to develop evidence-based recommendations for treatment.

Outcomes of interest included overall and progression-free survival, quality of life, tumour response rate and duration, and the toxicity associated with the use of anti-EGFR therapies.

The medline, embase, and Cochrane Library databases, the American Society of Clinical Oncology online conference proceedings, the Canadian Medical Association InfoBase, and the National Guidelines Clearinghouse were systematically searched to locate primary articles and practice guidelines. The reference lists from relevant review articles were searched for additional trials. All evidence was reviewed, and that evidence informed the development of the clinical practice guideline. The resulting recommendations were approved by the Report Approval Panel of the PEBC, and by the Head and Neck Cancer DSG. An external review by Ontario practitioners completed the final phase of the review process. Feedback from all parties was incorporated to create the final practice guideline.

The electronic search identified seventy-four references that were reviewed for inclusion. Only four phase iii trials met the inclusion criteria for the present guideline. No practice guidelines, systematic reviews, or meta-analyses were found during the course of the literature search. The randomized controlled trials (RCTS) involved three distinct patient populations: those with locally advanced HNSCC being treated for cure, those with incurable advanced recurrent or metastatic HNSCC being treated with first-line platinum-based chemotherapy, and those with incurable advanced recurrent or metastatic HNSCC who had disease progression despite, or who were unsuitable for, first-line platinum-based chemotherapy.

These recommendations apply to adult patients with locally advanced (nonmetastatic stages iii-ivb) or recurrent or metastatic (stage IVC) HNSCC. Platinum-based chemoradiation remains the current standard of care for treatment of locally advanced HNSCC. In patients with locally advanced HNSCC who are medically unsuitable for concurrent platinum based chemotherapy or who are over the age of 70 years (because concurrent chemotherapy does not appear to improve overall survival in this patient population), the addition of cetuximab to radical radiotherapy should be considered to improve overall survival, progression-free survival, and time to local recurrence.Cetuximab in combination with platinum-based combination chemotherapy is superior to chemotherapy alone in patients with recurrent or metastatic HNSCC, and is recommended to improve overall survival, progression-free survival, and response rate.The role of anti-EGFR therapies in the treatment of locally advanced HNSCC is currently under study in large randomized trials, and patients with HNSCC should continue to be offered clinical trials of novel agents aimed at improving outcomes.

Chemoradiation is the current standard of care for patients with locally advanced HNSCC, and to date, there is no evidence that compares cetuximab plus radiotherapy with chemoradiation, or that examines whether the addition of cetuximab to chemoradiation is of benefit in these patients. However, five ongoing trials are investigating the effect of the addition of EGFR inhibitors concurrently with, before, or after chemoradiotherapy; those trials should provide direction about the best integration of cetuximab into standard treatment. In patients with recurrent or metastatic HNSCC who experience progressive disease despite, or who are unsuitable for, first-line platinum-based chemotherapy, gefitinib at doses of 250 mg or 500 mg daily, compared with weekly methotrexate, did not increase median overall survival [hazard ratio (hr): 1.22; 96% confidence interval (ci): 0.95 to 1.57; p = 0.12 (for 250 mg daily vs. weekly methotrexate); hr: 1.12; 95% ci: 0.87 to 1.43; p = 0.39 (for 500 mg daily vs. weekly methotrexate)] or objective response rate (2.7% for 250 mg and 7.6% for 500 mg daily vs. 3.9% for weekly methotrexate, p > 0.05). As compared with methotrexate, gefitinib was associated with an increased incidence of tumour hemorrhage (8.9% for 250 mg and 11.4% for 500 mg daily vs. 1.9% for weekly methotrexate).