AACR Logo The link between smokeless tobacco and cancer is not new, but it is now getting an official affirmation. A team from the American Association For Cancer Research (AACR) has shown that a chemical known as (S)-N’-nitrosonornicotine, or (S)-NNN in smokeless tobacco is apparently a strong oral carcinogenic factor.

For the research, the team injected two variants of NNN called (S)-NNN and (R)-NNN into 4 sets of 24 rats. Each of the 4 groups was either given individual chemicals or a combination of both. One of the groups was administered tap water.

“(S)-NNN is the only chemical in smokeless tobacco known to cause oral cancer. This finding provides mechanistic underpinning for the epidemiologic observations that smokeless tobacco products cause oral cancer,” commented Silvia Balbo, Ph.D., research associate at the Masonic Cancer Center of the University of Minnesota in Minneapolis, Minn.

As per the observations, rats receiving (S)-NNN alone seemed to lose weight after a span of 1 year and died at the end of 17 months. Moreover, these rats suffered from oral and esophageal tumors including cancers of the tongue, soft palate, buccal mucosa and pharynx. On the other hand, only 5 and 3 of the 24 rats receiving (R)-NNN suffered from oral and esophageal tumors, respectively.

If the use of smokeless tobacco products cannot be curtailed for some reason, it is crucial to at least reduce the amounts of (S)-NNN used in the making of the same. Further clinical trials are required to comprehend the precise mechanisms involved in the use of smokeless tobacco.

The findings are presented at the AACR Annual Meeting 2012.