Smoking & Cancer

Smoking & Cancer Doctors studying the seeming connection between smoking and lung cancer need more facts before they can firmly answer such questions as: Is it just coincidence? Does smoking cause the cancer? If so, how? From a few hundred cases studied in the U.S. and Britain have come suggestive leads, but nothing more. Last week the British Medical Journal reported on a massive study which goes a long way toward answering some of the inquiring physicians' basic questions, and also raises some new ones.

There is a definite relationship between smoking and lung cancer, conclude two statisticians working for Britain's Medical Research Council. Dr. Richard Doll and Professor A. Bradford Hill checked the life histories of 1,465 patients with lung cancer (1,357 men, 108 women), and compared their accounts with those of an equal number of men & women of the same ages who were in the same hospitals but with different ailments. To rule out local variations, they spread their work over five British cities and two rural counties.

Of the men with lung cancer, only half of one percent were nonsmokers; 25% were "heavy smokers" (25 or more cigarettes a day, or the equivalent in pipe tobacco, for ten years or longer). Of the male non-cancer patients, 4 1/2% were non-smokers and only 13 1/2% were heavy smokers. The death rate from lung cancer among non-smokers aged 45-64 was negligible; among heavy smokers it ran from 6% to 10% for the same age span. There was a puzzling contrast in the figures for women: among them, 37% of lung-cancer patients were nonsmokers.

The British researchers found no notable difference between smokers who inhale and those who don't. Pipe smokers seem less likely to get lung cancer than cigarette smokers, and using a filter or holder with cigarettes seems to afford a little protection. Heavy smokers in the Dorset hills suffer less from lung cancer than their city cousins. This, say the researchers, may be because something in cigarette smoke, combined with something in city air, is a more powerful stimulator of lung cancer than either factor alone.

In sum, they say, "the association between smoking and carcinoma of the lung is real." But they do not go so far as to say that smoking is the sole cause of the increased death rate, or even that it is a factor in every case. There is still much to be learned about how it works.

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