I was all for snus. but i read something that it has been proven to cause pancreatic cancer. that kind of worried me a little bit. But one thing that made me feel a little better. they said out of i think 10 thousand or 20 thousand snus users, 9 of those will get pancreatic cancer from snus. and four of them will get pancreatic cancer from not using any tobacco products at all. So i guess the correlation is weak at besT?
You are thinking of the research project published in The Lancet, Volume 369, Issue 9578, Pages 2015 - 2020, 16 June 2007. It was a statistical examination of the comparative medical history of male Swedish construction workers who used snus for a long time and never smoked vs. those who neither smoked nor snused. It did not conclude snus was "proven to cause" pancreatic cancer. The authors suggested that snus might be "added to the list of tentative risk factors" which may, or may not, be associated with some increased risk for it, pending further investigation. There are some things about that study of epidemiological data which are anomalous (peculiar or inconsistent) both internally and in contrast with other data. They found a small statistical increase in pancreatic cancer among one of the several age groups, but both younger and older cohorts did not show the same evidence of increased incidence of pancreatic cancer. Further, it has been contradicted by other, more comprehensive data from studies such as those in
THIS THREAD, and the construction worker data suggesting some possibility of this risk has not been replicated elsewhere.
I have not spent much time carefully considering these issues, as they aren't my main motivation for using this stuff, and I am not any sort of expert, but for what it's worth this is how I personally evaluate this information:
1. Given that any particular type of cancer is a randomly occurring low probability event (even low probability among lifelong heavy smokers for example, and also randomly occurring among people with no risk factors at all for no particular reason) it is notoriously difficult to measure probability of risk, because a relatively few random individual cases can skew the small percentages one way or another so easily. Given the internal inconsistency among the groupings in the Lancet published data, and given the fact that other data contradicts it, it seems most probable to me, but not certain, that there is not an increased risk of pancreatic cancer. But, one could not say with certainty that there is absolutely zero increased risk of this particular cancer, even though other data from other samples in other studies did not show statistical evidence of a risk.
2. Other forms of cancer were found not to be significantly associated with long term snus use in any of the academic studies I have found, including the anomalous construction worker sample.
I have no opinion on how any of this might compare to cancer risk of e-cig vapor, and nobody else can either, since most cancer generally has a very long gestation period, and an association with cancer could not become known for decades. If I began intake of a powerful carcinogen today, it is unlikely that it would have time to develop an actual cancer before I die of other unrelated routine complications of old age first within about 25 years. A recent publication of some experimental results produced evidence to support a new hypothesis that people with certain kinds of lesions already existing in their mouth could possibly have an increased risk of mouth cancer from exposure to pure nicotine alone as occurs with using nicotine vapor, but it is a hypothesis (theory) of a mechanism of action which might (or might not) be a way for cancer to start, and there is at this time no data from human users to show whether inhaling nicotine alone does actually result in an increased probability of that kind of cancer actually occurring via that experimentally observed process, and if so how significant any such increase in risk might be.
That was all a long winded way of saying no, that study did not demonstrate pancreatic cancer can be caused by snus, but unlike the other studies it failed to rule it out as a possibility; and that nobody will really know anything about nicotine in vapor form & any associated cancer risk for a long time because it hasn't been around long enough, regardless of what testing or study is or is not performed on it for other things.
