Radiation Therapy With or Without Cisplatin in Treating Patients With Stage III-IVA Squamous Cell Carcinoma of the Head and Neck Who Have Undergone Surgery

PRIMARY OBJECTIVES: I. To evaluate the disease-free survival (DFS) of patients with stage III-IV squamous cell carcinoma of the head and neck (SCCHN) and disruptive p53 mutations after primary surgical resection followed by postoperative radiotherapy (PORT) alone or PORT with concurrent cisplatin. SECONDARY OBJECTIVES: I. To evaluate the DFS of patients with stage III-IV SCCHN and non-disruptive p53 mutations after primary surgical resection followed by PORT alone or PORT with concurrent cisplatin. II. To evaluate the DFS of patients with stage III-IV SCCHN and p53 wild type after primary surgical resection followed by PORT alone or PORT with concurrent cisplatin. III. To evaluate toxicities of PORT alone or PORT with concurrent cisplatin. IV. To evaluate p53 mutation as a predictive biomarker of survival benefit given post-operative concurrent radiation and cisplatin. V. To identify potential genomic alterations in addition to TP53 mutations that may be developed to a novel treatment approach. OUTLINE: Patients are randomized to 1 of 2 treatment arms. ARM A: Patients undergo intensity-modulated radiation therapy (IMRT) once daily (QD) 5 days a week for 6 weeks in the absence of disease progression or unacceptable toxicity. ARM B: Patients undergo IMRT QD 5 days a week and receive cisplatin intravenously (IV) over 1-2 hours weekly for 6 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 6 months for 3 years and then every 12 months for 7 years.