Smoking does not cause cancer.

[Update 10-Deember-2007 @ 17:38, since this post went up 3 days ago, I have had a few search engine hits using the keyword smoking on this post. To dispel any possible confusion: the title is ironic. Smoking increases the risk and incidence of cancer. So do oral contraceptives. However, both also have positive side effects. Smoking appears to reduce the incidence of Alzheimer's. Researchers are currently looking into a nicotine like compound found in a marine creature as a possible treatment for Alzheimer's (why they don't look at tobacco, I don't know - probably because it would not be politically correct). Oral contraceptives reduce the incidence of certain rare forms of cancer, however, the sum of cancers prevented and cancers caused show an overall increase in the number of cancer cases.]

I am still in an anti-spinning mood.

Eleven years ago or so, the Ottawa Citizen ran a front page article on the pill. The headline (in the biggest font I ever recall seeing) was something like “PILL DOES NOT CAUSE CANCER”.

The lead-in paragraph went something like:

After more than 30 years, women all over world can breath a collective sigh of relief as an extensive study proves that the pill does not cause cancer.

Of course, buried deeper in the article was a short throw away paragraph stating that women on the pill do experience increased incidence of cancer, but 10 years after stopping use the rate drops similar levels as women who have never used the pill.

I think the report all this was based on is "Evidence-guided prescribing of combined oral contraceptives: Consensus statement" from the September 1996 issue of the journal Contraceptive. However, I have never read it, although, I was tempted yesterday to pay $30 to get a copy (after subscribing to the site), but I still prefer to read it for free - so, if anyone has a copy they would like to send me, I would be much obliged. Anyway ...

I immediately made the connection with smoking because research shows that 10 years after you quit your risk of cancer drops to levels similar to that of a non-smoker. Whenever I mention this to people they immediately respond that I am confusing two separate things and should leave the heavy thinking to the experts (ok, maybe I infer that last part).

So, I abstract it for them: "If I tell you that consumption of substance S results in an increased incidence of cancer. Is substance S a carcinogen?"

The answer back is always, "Yes, but I still think you are confusing things."

For the extra curious:

Oral contraceptives increase the risk of breast (1.3x), cervical (1.5x - 2.5x) and liver cancer. It is always referred to as "slight increase". They reduce the risk of ovarian (0.4x - 0.8x) and endometrial (0.5x) cancer. It is always referred to as "significant decrease".

Lung cancer rates among non-smokers is 0.5%. Heavy smoking increases the risk 20-fold to 10% (or spun the other way, heavy smokers have a 90% chance of NOT developing lung cancer).

Demographic studies show that people over the age of 90 have a 1 in 9 chance of developing lung cancer. The moral? Living to extreme old age is a greater risk factor for lung cancer than smoking.

I love information, it can be presented in so many interesting ways and still be accurate.


ghee said…
so,i should not stop smoking at all?

Happy weekend!
Richard said…
Despite the title of my post, smoking does cause cancer. I am simply complaining about the way information is presented to people. Oral contraceptives cause cancer too, however, the information is presented in such a way as to dismiss it (10 years after stopping, your risk drops to the same level as a non-user).Well, with this kind of argument, tobacco companies could argue that "while there is an elevated risk of cancer while smoking, the risk disappears 10 years after quitting".

Sorry, but that is disingenuous spin.
KayMac said…
I still plan on living past 90...wink!
Richard said…
kaymac: I hope you do. I was listening the other day to an interview on CBC radio with a man 103 years old - he was clear, lucid and sharp. He was 13 when a huge explosion rocked through halifax in 1917. Yuo can about it here.

I fear my prospects for living that long are pretty slim. On both sides of my family, male relatives have tended to die before age 70 (usually of stroke). The oldest blood relative I know was my father's mother who died in her late 90s.
tin-tin said…
ate ghee, don't stop. hehehe. joke!!!

but ate ghee, try to think of those around you. who doesn't smoke but might get cancer also coz of second hand smoking.

i am sorry richard coz this is a reply to ate ghee's comment but i think my reply is my comment also. hehehe ;p
b said…
All this spinning makes me very dizzy! And even your conditional argumentation is lost on these people? I always find it interesting when people agree to the logic of your statement but then throw in an (usually) unsubstantiated disclaimer like "but I still think you are confusing things."
aCey said…
i think you'll make a good journalist, richard. my writing teachers (who are, by the way, journalists) say that people who love information and presenting them are fit for the job... or something like that. :)

i'm curious about contraceptives now (although i won't need them yet. haha!).
Richard said…
tin-tin: you are right, your comment is a comment. Aside fromthe health risks, smoking is also smelly.

breal: people don't want to believe what they don't want to. My earliest memory is regarding Star Wars. I was interested in seeing it because I was already a big sci-fi junkie and reruns of Star Trek can only take you so far. When I declared that I did not like it, people replied, "You didn't see Star Wars." Of course I did, but since I was contradicting them and the whole phenomena surrounding it, clearly I had to be wrong. Simplest explanation was to deny I had seen the movie.

This happens quite frequently, the two pack a day smoker who insists they smoke much, much less. The gambler who denies they are in trouble. The person in an abusive relationship who knows their partner really, truly loves them. The slave holder who sees no humanity in their slaves.

Reality, I find, for most people is a lot less rooted infacts and truth than in what is conventionally accepted (whether true or false). I wonder how many people in the US would claim they were never initially for the war in Iraq (conveniently ignoring that they were in favour 6 years ago)?

It is alot like the Indian rope trick (where a rope rises up, a boy climbs the rope, the angry fakir climbs up after him, chops him up and throws down the body parts, reassmbles them and then reanimates the boy). Many have claimed to have seen it, yet, Penn and Teller were unable to substantiate any claims. They posit that people see bits and pieces of it, but collectively lie or decieve themselves into believing they have seen the whole thing from beginning to end.

Human memory is extremely plastic. So are beliefs.

acey: I am not sure I would make a good journalist. I took a freelancing course this past year (given by a journalist). It was a practical course and we were expected to write an article. All my proposals were turned down (suitable as an encyclopedia entry I was told, but not as an article with focus).

Even in this blog, I try not to tell people things, I just like to say, "Hey! Have you thought about it from this perspective?"
carra said…
Statistics are always twisted the convenient way. I love reading things like that. I am a smoker and not worried about getting cancer,in fact I love smoking and don't intend to quit any time soon.Yet I agree smoking is bad for me but so is the pill, what is worse getting a cancer by avoiding unwanted babies or getting one while spending late evenings writing chain-smoking, I choose latter. However smoking kills. But one thing is for sure, you don't have to be a smoker or take the pill to get cancer, there is more to it. My brain has retired and so should I.
Richard said…
carra: unrepentant aren't you? Yes, the odds are in your favour of not acquiring cancer from smoking. However, you odds in your favour that you will die of coronary or heart disease caused by smoking.
carra said…
So be it Richard I am not going to drive myself crazy that my one and only harmful habit may kill me. I am going to die anyway, maybe tomorrow I'll be hit by a car, worrying about it or staying at home for the rest of my life is not a solution is it?
Richard said…
carra: worrying about it is not going to solve anything. I accept that people engage and indulge in all sorts of irrational behaviours - which can include eating too much and not exercising enough (did you know that the definition of obesity was changed more than a decade ago? Making the threshold lower.)
ingrid said…
Smoking has many other affects other than cancer. This includes:
*increased blood pressure
*hardened blood vessels etc etc.

I think that this argument is also about morbidity and quality of life. Not just risk of death.
Richard said…
ingrid: I am in no way trying to be an apologetic for smoking. The general detriment it poses to life is pretty well established.

My main gripe was about the Ottawa Citizen headline years ago about the pill not causing cancer and applying the same line of argument about smoking not causing cancer

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