Swallowing outcomes following primary surgical resection and primary free flap reconstruction for oral and oropharyngeal squamous cell carcinomas: a systematic review protocol

Abstract

Review question / objective What are the swallowing outcomes of primary surgical resection with primary free flap reconstruction with or without adjuvant therapy for the treatment of oral or oropharyngeal squamous cell carcinoma? The objective of this systematic review is to investigate swallowing outcomes following primary surgical resection and free flap reconstruction for the treatment of patients with oral and oropharyngeal squamous cell carcinoma. More specifically, the objectives are to evaluate dysphagia following primary surgical resection with or without adjuvant therapy with the use of objective investigations (videofluoroscopy, fiberoptic endoscopic evaluations of swallowing, manometry, gastrostomy dependency and tracheostomy dependency) and subjective questionnaires (MD Anderson Dysphagia Inventory, University of Washington Quality of Life Questionnaire and Functional Oral Intake Score). Background There are approximately 264,000 cases of oral-cavity malignancies and 136,000 cases of pharyngeal malignancies diagnosed annually worldwide.1 The oral cavity begins at the vermillion border of the lips and extends to the junction of hard and soft palate and circumvallate papilla of the tongue. The anterior tonsillar pillars serve as the boundary between the oral cavity and oropharynx. The oropharynx is made up of the posterior and lateral pharyngeal walls, tonsillar regions, base of tongue and soft palate. The etiology of oral and oropharyngeal squamous cell carcinoma (OPSCC) has been strongly linked to the intensity and duration of smoking and alcohol use.2,3 Recently, the human papilloma virus (HPV) has been linked to the development and rise in incidence of OPSCC.4 Patients with HPV-positive disease are typically younger, non-smokers and have a favorable prognosis for long-term survival, compared with their HPV-negative counterparts.5 Therefore treatment regimens have shifted toward organ preservation techniques with the goal of improving functional outcomes such as swallowing. Head and neck cancers are staged according to the International Union Against Cancer (UICC) TNM Classification of Malignant Tumors Edition 7 or American Joint Committee on Cancer (AJCC) Staging System Edition 7.6,7 Components of both these systems include: local tumor growth (T), regional lymph node spread (N) and distant metastasize (M). The goal of the TNM staging system is to assist in planning treatment and aid in prognosis.8 Early stage (I/II) and advanced stage (III/IV) malignancies will have immensely different treatment regimens ranging from single modality treatment, multiple modality treatment to palliation. Depending on the treatment modality utilized, functional outcomes will vary greatly.9 Patients undergoing treatment aimed at palliation are more likely to have worsening dysphagia as treatment would be focused on comfort. Therefore, it is paramount to compare the swallowing outcomes of varying treatment regimens with malignancies of a similar stage. The prognosis from head and neck cancer is improving with treatment protocols utilizing surgery, radiotherapy and chemotherapy. The combination of chemoradiotherapy has been shown to improve survival outcomes; however, it is associated with increased long-term toxicity.10 The utilization of surgery to maintain disease control, in advanced stage malignancy, whilst preserving function, is a difficult task, as it typically involves mandibulotomies and defects within the head and neck.11,12 Surgical reconstruction techniques with the use of free vascularized flaps allows for improvement in functional and cosmetic outcomes.13 Free flaps can be transferred with their associated nerves, allowing for additional sensory and motor function.14 Commonly used soft tissue donor sites include the radial forearm and anterolateral thigh graft. Primary reconstructions are performed at the time of resection, whereas secondary reconstructions are performed as a separate procedure following resection. Prim