Читать книгу Hypopharyngeal Cancer - Группа авторов - Страница 18

Betel quid/areca nut use has been common in South and Southeast Asia and the Asia Pacific region for a long time and is common among migrated communities in Africa, Europe and North America, and is estimated to be consumed by 400–600 million people worldwide [51]. Its use is socially acceptable among all sections of society, including women and quite often children. In its common form, betel quid is a combination of betel leaf, areca nut and slake lime (aqueous calcium hydroxide paste) [52]. There is a great spectrum of variation in ingredients and ways of preparing betel quid, including the addition of tobacco in many countries, but with political involvement has almost disappeared in Thailand [36]. There are several forms of areca nut (green unripe, ripe but raw, baked roasted or boiled; fermented; or, processed with sweeteners and flavours), betel (leaf or inflorescence) and ingredients consisting of spices, condiments, tobacco and lime. Chewing tobacco as well as smoking and drinking alcohol are habits that are on the rise. Chewing of areca nut alone is widely practiced mainly by women in South and South East Asian populations. Carcinogenic nitrosamines derived from areca nut are formed in the saliva and swallowed, hence its association with oral cavity, pharynx and oesophagus cancers [53, 54].

From the 1990s, the habit of chewing betel nut/areca nut has increased in Taiwan and more so among children and youth. Unlike chewers from most countries in South-East Asia, who use mature betel fruit, the Taiwanese chewer commonly used fresh, unripe betel fruit with slaked lime as an essential ingredient, and tobacco is never added to any type of chewing quid. However, cigarette smoking is also common, especially with areca/betel quid chewers, but Taiwanese with both chewing and smoking habits are rare to find [55]. However, not adding tobacco to the chewing quid has been shown to be a positive independent carcinogenic role on the pharynx and not the larynx [51].

Evidence from India has shown that bidi smoking (small hand-rolled cigarettes made of tobacco and wrapped in tendu or temburni leaf, which are plants that are native to Asia – Diospyros melanxylon), which accounts for about 60% of smoked tobacco products, is significantly related to the risks of hypopharyngeal cancer (p < 0.001), and is associated with the number of cigarettes smoked a day and the age at onset of smoking, and the duration of smoking increases the cancer risks [56].