Monday, April 19, 2010

Do former smokers get more lung cancer?

The anti-smoker brigade issues press releases on a regular basis. Over the last couple of years, for example, they've announced a series of studies which purported to show that smoking bans immediately reduce hospital admissions for cardiovascular disease.

Widely distributed and highly publicized by the press, these studies, more often than not, are rather quickly shown to be sadly lacking in scientific integrity. But, the criticisms of these studies by knowledgeable experts are seldom reported in the mainstream media. So, the anti-smoker fanatics are free to continue their campaign of deceit and deception without fear of censure in the press.

For a prime example of what I'm talking about, check out this blog entry by anti-smoking activist Dr. Michael Siegel and his critique of the latest miracle study from Toronto, Canada. And, you can read more about these miracle studies on my Dec 10, 2009 blog entry.

But, let's look at some other facts about smoking and smoking related deaths that will never make headlines. Like the analysis critical of the smoking ban miracle studies, they're hidden away on obscure websites and blogs and scientific journals which the general public seldom reads.

For instance, an organization called the Lung Cancer Alliance claims that over 60% of all new lung cancer cases are among former smokers and those who have never smoked. “Over 60% of new cases are never smokers or former smokers, many of whom quit decades ago.”

In fact, they have a nice little chart on their page which breaks it down. It claims that current smokers account for 35% of new lung cancer cases, former smokers 50% and never smokers 15%.

Imagine. More former smokers are being diagnosed with (and presumably dying from) lung cancer than current smokers. I say “presumably dying” because, according to the Lung Cancer Alliance: “The majority of lung cancer patients are being diagnosed so late that they will die within a year.”

That's quite a startling revelation. It's easy to understand why the anti-smoker crowd and their allies in the press corps would hesitate to make that information available to the general public. Because it suggests that quitting the habit is no defense against lung cancer. In fact, if 50% of new lung cancers are found in former smokers, that, in turn, suggests that former smokers are at greater risk of developing lung cancer than smokers.

The same website claims there are over 40 million smokers in the US and over 45 million former smokers. And, if 50% of new lung cancer cases are among the 45 million who quit, and only 35% of new cases are among the 40 million who continue to smoke, well . . . you don't have to be a math major to figure it out.

Let's assume that the number of new lung cancer cases will correlate to actual lung cancer deaths. This is not an unreasonable assumption since only 15% of lung cancer patients survive more that five years, and as noted by the Lung Cancer Alliance “The majority of lung cancer patients . . . will die within a year.”

There are approximately 160,000 deaths from lung cancer every year in the US. If 35% of lung cancer deaths are among current smokers, that's 56,000 lung cancer deaths. There would be 80,000 deaths among former smokers (50% of 160,000). Therefore, former smokers are at a higher risk of developing lung cancer and dying from that dread disease than current smokers.

These are not precision numbers, but I believe they are sufficiently accurate to illustrate my point. And, to re-emphasize my point, according to the figures provided by Lung Cancer Alliance, more former smokers than current smokers will contract lung cancer and eventually die from that disease.

But, the anti-smoker crowd has been telling us for decades that the only way for smokers to escape lung cancer and other smoking related diseases, is to quit using the foul smelling weed. So, what gives?

Up here in the Great White North, Health Canada is very careful about disclosing the number of smokers, former smokers or non-smokers who die from lung cancer. Instead, they claim that 88.6% of lung cancers among males, and 62.5 among females, are attributed to smoking. Is there some legitimate reason that Health Canada lumps them all together, obscuring the number of smokers and former smokers allegedly dying from lung cancer?

I know what you're thinking. Does it really matter if more former smoker than current smokers die from lung cancer? After all, if you add up the numbers, that still means that 85% of lung cancers are caused by smoking.

And, if you believe the statistics from the anti-smoker crowd, you'd be correct. Unfortunately, I've become very cynical about all statistics provided by the fanatics. When it comes to smoking, they seem to ignore even the most basic principles of science and statistical analysis.

In this case, it's something called “reversible association”. In other words, if the ``cause'' is removed (e.g. people stop smoking) the proportions contracting the disease should reduce. And, smoking rates have been declining steadily for the past 45 years, while lung cancer rates have been mysteriously increasing.

Don't you just love a mystery?

5 comments:

Anonymous said...

Simply, we have alot more former smokers than we have current smokers due to the fact that a lot of the former smokers started during the earlier eras when the smoking population was much larger. It just proves how long lasting the damage done is. Basically, you have, as a smoker, started a dna damage chain reaction that will very likely come back to bite you in the ass hard. But hey, live it day by day, death doesnt hurt. the only dreadfull thing about it is thinking about it.

The Old Rambler said...

Anonymous

Some valid points. But . . . there are a few flaws in the argument.

First, “a lot of the former smokers started during the earlier eras when the smoking population was much larger." Using data from Health Canada's latest SAMMEC tables, you can calculate that, in the age group between 15 and 19, there are 333,569 current smokers and 279,768 former smokers. To suggest that, if those former smokers die of lung cancer at 70, 80, 90 years of age, their death was due to smoking borders on the insane.

It's a statistical illusion passed off as truth.

Second, “You have, as a smoker, started a dna damage chain reaction that will very likely come back to bite you in the ass hard.” That claim is simply not supported by the evidence. Since less than 1 in 10 smokers will actually die from lung cancer, you'll have to explain why over 90% of smokers do not develop, or die from, the disease.

The more factual statement might be: A few smokers (less than 1 in 10) may start a DNA damage chain, which, possibly in synergy with other carcinogenic exposure (asbestos, radiation, radon gas, or a dozen or more other risk factors), may develop into lung cancer and at some point (20 to 70 years or more) following exposure to tobacco smoke may cause death, whether they have given up smoking during that time or not.

Lastly, “death doesn't hurt. the only dreadful thing about it is thinking about it.” Your sarcasm is wasted on this old ramblin' man. I can't claim to know if death itself “hurts”. But, I do know that the manner of death, including lung cancer, can be very painful. I've seen it more times than I care to recall. But, in case you haven't heard the rumour, man was born to die. And, sometimes the manner of death can be very ugly indeed.

Your comment does contain one element of truth. “The only dreadful thing about it [death] is thinking about it.” So, stop wasting precious time worrying about something you can't change. Get on with living life your way, and let others do the same.

monkeyDluffy said...

Smoking is by far the function of crucial factor in lung cancer. More than 8 out of 10 diagnoses of lung cancer is thought to the significance of smoking. The longer a cigarette paper has been, and more packs per day smoked, the higher the risk. If a person stops smoking before cancer develops, lung tissue slowly returns to normal. Quitting smoking at any age reduces the risk of Lung Cancer.

Anonymous said...

Unfortunately monkeyDluffy, statistically speaking that just not the case. As I believe the writer was trying to point out, there are far more cases of former smokers getting lung cancer than current smokers. Also lung tissue never returns to normal, at best your looking at only a 2 to 5% increase to lung cancer, from the 8% you have as a full fledged smoker. So sad as it may sound being a current and/or former smoker leaves you a higher risk for the disease and depending on your genetic makeup, which is what most likely makes the difference anyway as 15% of lung cancer's diagnosed are by non-smokers. I just pray people stop judging the smokers and start trying to take the disease of lung cancer more seriously instead of judging someones "crutch" as we all have one and they are all harmful to your health.

Cabral said...

formers msokers are more likely to have a more significant smoking history, given that most people smoke for many years before quitting, whereas, any person that "currently smokes" is considered a "current smoker" regardless of whether they started a year ago or yesterday. Such person is considered a former smoker even though he or she has not smoked for a very long period of time and, therefore, has not caused himself or herself enough damage to develop lung cancer