Nasopharyngeal Carcinoma

Abstract

Nasopharyngeal carcinoma (NPC) is unusual in several ways. Its epidemiology, associated with ethnicity, genetic predisposition, viral, and environmental dietary exposure, is unique in itself. In addition, the predilection for certain geographic areas, with relative sparing of adjacent regions is noteworthy. Unjustly perhaps, NPC poses a formidable public health hazard to countries that are relatively compromised in their ability to provide the technical diagnostic and therapeutic approaches considered to be necessary for optimal management today. However, what sets it apart from most diseases is the anatomic challenge it presents to the oncology team because of the proximity of the nasopharynx to critical anatomic structures and the high predilection for distant metastasis once the primary and regional lymph‐node areas are extensively involved, which is all too frequent. In this chapter we discuss prognostic factors of importance in the management of NPC using the classification proposed earlier in this book. Factors will be considered by whether they relate to the disease itself, the patient (or host ), or the environment which influences the opportunity for optimal treatment and diagnosis. The classification may not always apply since, in the case of NPC, there may be overlap among factors and arbitrary placement of factors may be necessary. We will also attempt to categorize the available evidence into factors which are essential to our ability to treat the disease ( essential factors), those which add valuable information about the disease but do not affect treatment decisions ( additional factors), and finally those that are being described and may provide important understanding of disease behavior and therapeutic approaches in future years. In the interest of relevance to the treatment of the disease, and for brevity, the discussion of the final group of factors (those termed new and promising ), will be restricted to experience of patient outcome. Therefore, preclinical studies will not receive attention. Special attention to the classification of stage of disease will be given. This is because for NPC anatomic features are so important that a relevant and reproducible system of classification merits attention above other prognostic factors. In fact, few diseases received the same level of attention in the preparation of the 5th edition (TNM) stage classification of the International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC). A major revision of the NPC stage was accomplished by a substantial collaborative consultation among radiation oncologists in Southeast Asia, with support from diagnostic radiologists, pathologists, and surgeons there and elsewhere.