LUNG CANCER IN DOGS

To the Editor:— Dr. Joseph Berkson's letter inThe Journal, Feb. 27, 1960, page 967, prompts me to report a little item relating to the controversy over cigarette smoking in relation to lung cancer. I am reporting in narrative form, without specific documentation or figures. In the summer of 1956, while in Moscow, I visited the Academy of Medical Sciences. There, at luncheon with Prof. V. N. Chernigovsky and Prof. V. V. Zakusov, I asked about the incidence of disease in Russia. They said that it was about the same as in the United States. I then asked about the incidence of lung cancer. Their reply was that an increase in the incidence of lung cancer in the large cities of Russia has been noted but no significant increase in the incidence of lung cancer in rural areas has occurred. I then asked what was thought to be the cause