Chapter 14 - Melanoma

Summary

Introduction

Malignant melanoma, a neoplasm of melanocytes, has a lifetime risk of 1 per 75 people in North America, and accounts for only 5% of skin cancers, but is responsible for three times as many deaths as non-melanoma skin cancers (1). Both the incidence rate and mortality from the disease have increased significantly since the 1970s, though the former may be partly attributed to increased awareness and screening (2, 3). Melanoma is primarily a disease of white people; rates are up to 20 times higher in whites than in African Americans. Major risk factors apart from race include family history of melanoma, atypical or numerous nevi, sun sensitivity, a history of excessive UV exposure, immunosuppressed states, and occupational exposure to carcinogens (1).

Staging

Melanoma is staged using the widely accepted American Joint Committee on Cancer's (AJCC) TNM staging system, which was most recently updated in 2009 (4). This system defines stage by features of the primary tumor (T), the presence or absence of tumor spread to regional lymph nodes (N) and the presence or absence of metastasis to distant sites (M) (Table 14.1). The TNM classifications are then organized into anatomic stage groupings, which dictate prognosis, treatment options and are predictive of other expected features of the disease in a given patient (Table 14.2).