Playing With Numbers

"The American Cancer Society projects that lung cancer will be diagnosed in 213,000 Americans in 2007 and kill 160,000."

That's an almost 75% fatality rate, though it's probable that some or most of the newly diagnosed will not die within the year - the number of fatalities being a combination of people diagnosed this year & those diagnosed in previous years. Still it's sobering, especially if you or somone you know is one of the 213,000.

The article discusses the result of a recent survey & the statistics gathered from it, but I feel it is a bit misleading when it comes to the details. The headline reads:

"Many lung cancer cases in nonsmokers: study"

But in the first paragraph you'll find this:

"Up to 20 percent of women who develop lung cancer have never smoked, U.S. researchers found in a study that suggests secondhand smoke may be to blame."

It could just be me but the headline seems to imply that smoking isn't the cause of lung cancer that it's been labeled as being while the opening paragraph shifts the blame to the dreaded elusive second hand smoke.

The study quoted in the story deals with 1 million people surveyed but it does not mention any controls to look at second hand smoke as a factor. It has other problems as well:

"This would translate to about 20 percent of female lung cancer patients having been nonsmokers and 8 percent of males, they said. That compares with
American Cancer Society estimates of about 10 percent to 15 percent for all lung cancer patients.
'That estimate has been thrown about without any hard data to support it. This data sort of supports it,' Wakelee said.
Chang said that because more men smoke than women, women may be more likely to be exposed to secondhand smoke, even when they are classified as never-smokers.
'We know that secondhand smoke does increase the risk of lung cancer so it's likely that a lot of these cases we observe are attributable to that,' she said in a statement." (emphasis mine)

So an estimate that has been thrown around for years now finally has a study to back up its claims. Kind of at least. But then note that it's mentioned as a fact that second hand smoke plays a part in lung cancer development in non-smokers & a conclusion is made that since non-smokers obviously don't smoke that it must be second hand smoke which is giving them lung cancer. Oh, & that men are to blame for exposing non-smoking women to second hand smoke.

But don't worry - another study is on the way:

"Weill Cornell Medical College last week said it was starting a lung cancer study of 5,000 people working in industries with a high degree of secondhand smoke exposure, such as flight attendants, restaurant workers and entertainers."

Note that the sample is only 5,000 compared to 1 million in the study that the article focused on. Also I see some problems with the focus groups. Flight attendants have had a smoke free working environment for over 10 years (if I recall correctly) so it might be useful to compare the younger flight attendants (who never had a smoking environment) to the older ones (who have had a smoking environment) but it'd take some time for the youngin’s to age sufficiently to compare the two groups. Restaurant workers would probably be a little more problematic as the turn-over rate in that industry is very high, with most folks working in that field for a limited amount of time before moving on to something else.

Entertainers - the majority of them I know &/or know of smoke so finding a significant number of non-smokers in that field would be difficult. I can tell you that anecdotally more entertainers die of drug overdoses & other intoxicant-related problems that cancer. We just don't usually live long enough for the disease to develop. In the past few years I've lost several friends from the business. One died of liver trouble, another of heart failure, another of an overdose & another died when she crashed her car into a tree after drinking heavily. The one who died of heart failure was the only one who didn't smoke & his death was due to a rapid weight loss program he was on & the surgeries that accompanied it. It just strained his heart too much & it gave out on him.

That's only 4 people in a few years. Going back further I could name more but it'd still be a minority of the musicians I know I know a few musicians in the 70's & 80's. They've never smoked & do not appear to be having any cancer related problems. The musicians I know that have passed recently have all been in their 30's & 40's. Going back further than the past few years it opens to the 50's & early 60's at the top end. None have died of any form of cancer despite the majority of them having been smokers & the minority being exposed to smoke.

So while this is all based on my experience with entertainers & is by no means a comprehensive examination of that particular group. I don't think a larger sample would bear out much differently. I certainly don't think it would be supportive of any theories regarding second hand smoke as causing cancer.

I don't have much faith in studies for some of the reasons outlined above. They can be useful in predicting general trends IF the methodology is done correctly, but they should never be relied on to prove an antequent consequent relationship. This article tosses numbers about in a seemingly factual way & that'd be well & good, but when it attempts to make conclusions from those numbers then it loses credibility with me.

For the record I have always thought that cancer is genetic. Any external influences only serve to modify an existing condition. In other words smoking or being around second hand smoke will not cause cancer. What it will do is speed up the process of cancer that was encoded in your DNA from conception.

& from my experience cancer is not that big a concern for entertainers. Even if genetically an entertainer is at greater risk of developing some form of cancer over his/her life they usually don't live long enough to see it materialize. Drug addiction, alcohol addiction, a generally unhealthy lifestyle usually get most entertainers before cancer has a chance to do its thing. At least that's what I've tentatively concluded from my experience in the field, with the subset of entertainers that frequent the bar scene (musicians & dancers mainly). I'm open to being proven wrong, it'll just take something more solid than stats to convince me (like an explanation of how certain chemicals contained in smoke mutate healthy cells into cancer without having any predisposition for cancer in that cell's make up).

Posted by Publicola at February 9, 2007 07:40 PM | TrackBack