Oesophageal cancer: an overview of a deadly disease

Oesophageal cancer is the eighth most common cancer worldwide, and the sixth most common cause of death from cancer. From a worldwide perspective, one of the most striking features of oesophageal cancer is the extreme geographic variation in incidence. At a global level, a 20-fold difference is seen in offi cial statistics between high-risk and low risk areas (1). This difference becomes even more striking when one looks at specifi c high-risk areas within certain countries. For example, while the incidence annually among women in North America is close to 2 cases per 100,000 population, the incidence among women in Iran has historically been estimated to be close to 100 times higher, and the annual death rate for OC in Linxian, People’s Republic of China exceeds 100 deaths per 100,000 population (1,2). One therefore needs really to consider areas where OC is endemic separately from non-endemic areas. Those areas in which OC should be considered endemic are listed in Table 1. It should be noted that even within these “hotspots” of OC, there is extreme variation within relatively short geographic distances (1-3). The vast majority of oesophageal cancer consists of either oesophageal squamous cell carcinoma (OSCC), or adenocarcinoma (AC) (5). Other malignancies constituting less than 1% of total oesophageal malignancies include small cell carcinoma, melanoma, malignant mesenchymal tumours (including Kaposi’s Sarcoma), and lymphomas. From a global perspective, OSCC accounts for approximately 80% of OC, and is clearly the predominant type in endemic areas (1,2,4,5). OSCC tends to occur more commonly among the black population (6), while AC is increasing among the white population in nonendemic areas (7). While OC in general tends to be a male dominated disease (male:female ratio of 5-7:1), a common fi nding in endemic areas is a more evenly distributed incidence between genders, with male:female ratios of 1–2:1 (1,4,5). In many western countries, AC is increasing rapidly, and the incidence has surpassed that of OSCC. In the USA, for example, AC overtook OSCC as the predominant type in the late 1980’s and is now three times more common than OSCC, increasing at a rate of 5%-10% per year, making it the fastest growing cancer incidence rate in the country (7). One must bear in mind that the absolute numbers still remain relatively small compared to endemic areas. The overall incidence of OC continues to rise, with most of Oesophageal cancer: an overview of a deadly disease