Smokeless Tobacco and Oral Cancer: A Review of the Risks and Determinants

Abstract

ABSTRACT:Smokeless tobacco has been associated with oral cancer for many decades. The purpose of this article is to review research relevant to this association, including epidemiologic studies, studies of putative carcinogens such as tobacco-specific nitrosamines (TSNAs) and other contaminants, and possible cancer inhibitors. Epidemiologic studies addressing this issue primarily consist of case-control studies. They show that the use of chewing tobacco and moist snuff is associated with very low risks for cancers of the oral cavity and related structures (relative risks [RR] from 0.6 to 1.7). The use of dry snuff is associated with higher RRs, ranging from 4 to 13, while the RRs from smokeless tobacco, unspecified as to type, are intermediate (RR = 1.5 to 2.8). With regard to TSNAs, historical levels in American moist snuff products were higher than those in their Swedish counterparts, but levels in contemporary products are uniformly low. TSNA levels in chewing tobacco have always been low, but levels in dry snuff have been higher, including some very high levels in current products. In general, smokeless tobacco users are not exposed to significant levels of cadmium, lead, benzo(a)pyrene, polonium-210, and formaldehyde, when compared with concentrations of these compounds in foods. Finally, low oral cancer risk from smokeless tobacco use may be influenced by the presence of cancer inhibitors, mainly anti-oxidants, in smokeless tobacco products.

Oral Squamous Cell Carcinoma and Associated Risk Factors in Jazan, Saudi Arabia: A Hospital Based Case Control Study

“…In Sweden a form of smokeless tobacco called snus is reported to have a very minimal link in causing oral cancer (Rodu and Jansson, 2004;Weitkunat et al, 2007;Lee and Hamling, 2009). But in other parts of the world such as in the African country of Sudan, it is seen that Toombak and Safa (smokeless tobacco) showed a strong association with oral cancer (Elbeshir et al, 1989;Idris et al, 1995a;1995b).…”

Smokeless Tobacco (Shammah) in Saudi Arabia: A Review of its Pattern of Use, Prevalence, and Potential Role in Oral Cancer

“…ST is used without burning the product, and can be used orally or nasally. Internationally, there are more than twenty eight types of orally used and two types of nasally inhaled ST (Kuper et al, 2002;Rodu and Jansson, 2004). Oral ST products are positioned in the mouth, cheek, or lip, and are sucked (dipped) or chewed.…”

Cancer and mortality among users and nonusers of snus

“…1 However, in view of the comparably low levels of tobacco-specific nitrosamines in snus and the idea of using snus as a way of reducing smoking dose among inveterate smokers, [2][3][4] possible health consequences of snus use is presently the topic of intense debate. Several Swedish case-control studies concluded that there was no significant association between use of snus and head and neck cancer, [5][6][7] while a significant excess risk of pancreatic cancer was reported from 2 recent cohort studies.…”