Page 11 - Functional impairment and cues for rehabilitation of head and neck cancer patients -
P. 11
GENERAL INTRODUCTION
Head and neck cancer
Head and neck cancer (HNC), cancer of the upper aerodigestive tract above the level of the clavicles, annually affects around 3.000 people in the Netherlands with over 900 head and neck cancer (HNC) related deaths reported each year (1). The most common histopathological subtype, comprising over 90% of all HNCs, is squamous cell carcinoma, which originates from the mucosal lining of the upper aerodigestive tract. HNC is categorized by the anatomical subsite it originates from, including the oral cavity, oropharynx, larynx, hypopharynx, nasopharynx, and nasal cavity and paranasal sinuses (figure 1). The most common risk factors are alcohol and tobacco abuse. However, also viral infections with the Human Papilloma Virus (HPV) and Epstein Barr Virus (EBV) play an important role in the carcinogenesis of oropharyngeal and nasopharyngeal cancer (2, 3).
Figure 1 Schematical overview of the subsites of the head and neck area.
Treatment and functional impairment
Historically, surgery alone was the first choice for early stage HNC treatment, combined with radiotherapy for advanced disease. Some thirty years ago, organ-preserving therapy protocols, including (chemo)radiotherapy ((C)RT), emerged into clinical practice and came to play an increasingly important role in the treatment of HNC. However, it soon became clear that organ preservation was not synonymous with function preservation. Despite organ preservation, vital functions of the head and neck area (e.g., swallowing, chewing, and speaking) are often affected, not only due to the (extent of) the tumor but also due to the side effects of the treatment (4-6). One of the vital functional limitations after HNC treatment is swallowing impairment, or dysphagia. Together with the associated weight loss and feeding tube dependency, dysphagia is often referred to as the most serious and debilitating side effect, which can cause (silent) aspiration and, with that, pneumonia (5, 7-10). Impaired mouth opening, or trismus, also commonly occurs after treatment for HNC – especially when radiotherapy is used – and can interfere with daily functioning (11-16). Furthermore, voice and speech, vital in (social) communication, may get affected (17). Apart from these side effects, many patients have health
1
Introduction
9