Postoperative Radiotherapy and Panitumumab in High-Risk Salivary Gland Malignancies

Standard therapy for high-risk or locally advanced salivary gland malignancies is surgery followed by postoperative radiation therapy. Studies have shown the superiority of combined modality therapy compared to surgery alone. Despite the addition of postoperative radiation therapy, the five-year survival for locally advanced salivary gland malignancies is poor (less than 60%). In salivary gland malignancies, the epidermal growth factor receptor (EGFR) is expressed in 25-85%; in certain histological types, like salivary duct carcinomas, the expression is higher. EGFR is a promising target of anticancer therapy. In squamous cell carcinoma of the head and neck, a phase III trial utilizing cetuximab added to radiation therapy improved both locoregional control and overall survival compared to radiation alone. Panitumumab is a novel, human, IgG2 EGFR monoclonal antibody that may be better tolerated and more efficacious than cetuximab. Here, the investigators hypothesize that the addition of panitumumab to standard radiotherapy in locally advanced salivary gland malignancies will improve recurrence-free survival (RFS).