Saturday, August 18, 2007

Lung cancer & capitalism

I have been reading some quasi-medical literature on lung cancer and emphysema. The Wikipedia entry here, despite some wiki-criticism, seems to me an excellent start to the subject of lung cancer. The graph above I pinched from this survey. It shows nicely the 20 year lag between smoking and the contracting of lung cancer in the US and complements an earlier picture I provided due to Weiss. The survey also contains reference to a fascinating paper by Witschi (2001) ‘A Short History of Lung Cancer’.

I have for the past few months been scouring the pre-1950s literature for early medical insights into the connection between cancer and smoking – I knew, for example, that Adolf Hitler was very anti-smoking and, yes, it is true – many of the earliest recognitions of the connection (e.g. MĪ‹ller (1940)) were medicos from Germany who published in German. Robert Proctor has written a book eulogising the role of the Nazis in recognising the threat from cigarettes!

Some American environmentalists of the 1960s, like Rachel Carson – who emphasised the role of environmental chemicals in causing cancer - never mentioned tobacco smoke. This is a major oversight. Tobacco smoke is the most important carcinogen in the environment and the one that can be completely controlled. Recognising its existence has simple implications - don’t smoke and do not allow yourself to be exposed to secondary tobacco smoke.

Lung cancer describes a condition where tissue cells in the lung grow out of control. It is the major cause of cancer-related death among men and the second-greatest among women. It is more than 90% caused by inhaling tobacco smoke. There are various ways lung cancer can be treated (surgery, chemotherapy, radiotherapy) but it is one of the nasty cancers – it kills 86% within 5 years. The death that results from lung cancer is, in the words of one leading surgeon, ‘horrible’. Not in any sense a painless exit.

The changes made in cigarettes over recent decades have altered the types of lung cancers generated in humans. In early studies tar from cigarettes was painted onto the shaved backs of animals, like mice, and shown to produce cancers. With the advent of low-tar, low-nicotine cigarettes people smoke harder. They consequently do not reduce their cancer risks at all – the tobacco industry and medical authorities refer to this as compensation. Compensated cigarette smoking activates a new set of carcinogens in tobacco smoke – 'tobacco specific nitrosamines' and volatile carcinogens in the gas phase. These produce a distinct range of cancers - 'adenocarcinomas' rather than 'squamous cell carcinomas'. Passive smoking also produces its own range of tumors.

Cigarette products when consumed as intended have about a 0.2 chance of killing a smoker from these types of cancer outcomes alone. A smoker's overall health risks from smoking can be summarised by saying that they have a 1 in 2.5 chance of prematurely dying from a smoking-related disease. That this is not new news does not make it less than true.

That cigarette companies have continued to provide addictive products that they have known for 50 years have these devastating consequences makes me somewhat despondent about the human condition.

To say that issues of smoking are primarily questions of individual choice seems to me close to an outright lie. It is universally known that it is mainly young, immature kids who initiate this disastrous habit.

On the other hand creates puzzles for people such as myself. The smoking debate brings into question many of the basic issues I have accepted in my 35 years of work as an economist.

The case for letting people choose and the consequent 'gains-from-trade’, the notion that a profit-seeking firm would not find it in their self-interest to produce a product that they knew produced harm are both brought into question. Moreover there are a myriad of widely-discussed externalities (e.g. passive smoking) and much-less-discussed (though more important) issues of internalities (information failures and irrational choices that mean people make stupid decisions).

Related to the positive issues of trying to limit the harm from smoking are profound ethical issues about why societies have allowed things to continue to this point.

The tobacco smoking debate provokes uncomfortable and pessimistic thoughts.

5 comments:

Anonymous said...

Harry,

There needs to be an education campaign for pre-adolescents making them aware that great changes to the brain occur with the onset of adolescence and that when smoking appears be an option to improve confidence, a drug to regulate neurotransmitters would be a better idea.

As we have both observed, a carcinogen in tobacco smoke is reponsible for the regulation (indirectly) of consciousness modifying neurotransmitters.It seems to me that in advertising and in the media young adults could be portrayed (positively)as resorting to a kind of prescribed non carcinogenous "soma" in place of fags in order to help them overcome social awkwardness.

I know this seems a bit like the milkbar scenes of "A Clockwork Orange" but the drugs on tap there were necessarily fictitious for dramatic purposes.

Even if an education program did not advocate a "soma" it could still warn pre-adolescents that smoking tobacco will not help them with the approaching turmoil their brains will experience during puberty.

Steve said...

Harry,

Regarding the history of smoking, somewhere in the house I have a copy of a Paul Johnson column (from The Spectator, I think) about changing public attitudes to it. His basic claim, as I recall, was that it did have its critics as a filthy habit centuries ago, and it wasn't until the 20th century that the indoor habit of smoking really took off. (I wonder if it was only then, too, that the "benefits" of smoking were promoted to women - helps you stay slim, etc.)

It was an entertaining read, maybe not especially relevant to your post, but if I can tract it down I'll let you know.

hc said...

dany, My reading on youth smoking suggests that in addition to presenting smoking as an uncool activity it is good to emphasise then salient costs (athletic performance, loss of attractiveness) it is good to emphasise quitting risks. Youth underestimate risks of being unable to quit. The DeFranza studies referred to suggest these are large after only a few cigarettes.

Generally I wish I had been advised of the turmoil of adolescence. I agree a good move.

Steve, I have been reading these histories of smoking. There are several book-length treatments.

Cigarettes were not around in great numbers before 1880 and as the graph suggests were not very popular prior to 1920. There were early critics but lung cancer was very rare until 1900 - even then uncommon until the 1930s as graphs make clear.

Smokes were promoted to women as a slimming aid for sure - 'Have a Lucky (Strike) not a sweet' was popular in the late 1920s. It was accurate too - nicotine puts you off sweet food.

Anonymous said...

I've seen this graph before and I always wonder why it does not extend further than the 70's. Surely the data exists for it to be extended another 20 years?

I'd be interested to know if the graph tracked as nicely going forward.

hc said...

Steve, Lung cancer rates are still falling for men (though slightly different types of cancers) as are smoking rates so, yes, it goes forward. I'll try to dig up a better graph and post it.

By the way consumption per smoker is increasing as smokers switch to low nicotine brands - this could have impact on health response.

I am also interested in trends for earlier periods.