Histometabolic Tumor Imaging of Hypoxia in Oral Cancer: Clinicopathological Correlation for Prediction of an Aggressive Phenotype

Answer questions and earn CME/CNE The recently released eighth edition of the American Joint Committee on Cancer (AJCC) Staging Manual, Head and Neck Section, introduces significant modifications from the prior seventh edition. This article details several of the most significant modifications, and the rationale for the revisions, to alert the reader to evolution of the field. The most significant update creates a separate staging algorithm for high-risk human papillomavirus-associated cancer of the oropharynx, distinguishing it from oropharyngeal cancer with other causes. Other modifications include: the reorganizing of skin cancer (other than melanoma and Merkel cell carcinoma) from a general chapter for the entire body to a head and neck-specific cutaneous malignancies chapter; division of cancer of the pharynx into 3 separate chapters; changes to the tumor (T) categories for oral cavity, skin, and nasopharynx; and the addition of extranodal cancer extension to lymph node category (N) in all but the viral-related cancers and mucosal melanoma. The Head and Neck Task Force worked with colleagues around the world to derive a staging system that reflects ongoing changes in head and neck oncology; it remains user friendly and consistent with the traditional tumor, lymph node, metastasis (TNM) staging paradigm. CA Cancer J Clin 2017;67:122-137. © 2017 American Cancer Society.

Oral cancer is the sixth most common cancer worldwide, with a high prevalence in South Asia. Tobacco and alcohol consumption remain the most dominant etiologic factors, however HPV has been recently implicated in oral cancer. Surgery is the most well established mode of initial definitive treatment for a majority of oral cancers. The factors that affect choice of treatment are related to the tumor and the patient. Primary site, location, size, proximity to bone, and depth of infiltration are factors which influence a particular surgical approach. Tumors that approach or involve the mandible require specific understanding of the mechanism of bone involvement. This facilitates the employment of mandible sparing approaches such as marginal mandibulectomy and mandibulotomy. Reconstruction of major surgical defects in the oral cavity requires use of a free flap. The radial forearm free flap provides excellent soft tissue and lining for soft tissue defects in the oral cavity. The fibula free flap remains the choice for mandibular reconstruction. Over the course of the past thirty years there has been improvement in the overall survival of patients with oral carcinoma largely due to the improved understanding of the biology of local progression, early identification and treatment of metastatic lymph nodes in the neck, and employment of adjuvant post-operative radiotherapy or chemoradiotherapy. The role of surgery in primary squamous cell carcinomas in other sites in the head and neck has evolved with integration of multidisciplinary treatment approaches employing chemotherapy and radiotherapy either sequentially or concurrently. Thus, larynx preservation with concurrent chemoradiotherapy has become the standard of care for locally advanced carcinomas of the larynx or pharynx requiring total laryngectomy. On the other hand, for early staged tumors of the larynx and pharynx, transoral laser microsurgery has become an effective means of local control of these lesions. Advances in skull base surgery have significantly improved the survivorship of patients with malignant tumors of the paranasal sinuses approaching or involving the skull base. Surgery thus remains the mainstay of management of a majority of neoplasms arising in the head and neck area. Similarly, the role of the surgeon is essential throughout the life history of a patient with a malignant neoplasm in the head and neck area, from initial diagnosis through definitive treatment, post-treatment surveillance, management of complications, rehabilitation of the sequelae of treatment, and finally for palliation of symptoms.