In Scotland and Northern Ireland the deaths among the male population from lung cancer reached 150 per 100,000 in the late 1980’s. To the credit of health promotion bodies the death rate from lung cancer in these areas has actually decreased in recent years. However, there is an epidemic of lung cancer occurring in women in the late twentieth century. The epidemic in the female population lags that in the male by approximately 30 years. The postulated reason for this is that the modern habit of chain smoking cigarettes was taken up by males after World War I, whereas women did not take up smoking in large numbers till after the second World War. Lung cancer now kills more women in Western Europe and the United States of America than breast cancer.

Lung cancer is highest in areas where smoking is most prevalent. It is therefore more common in inner city urban areas and in social classes 4 and 5. Clusters of increased incidence also occur in areas where there is high environmental exposure to other carcinogens. This may explain some cases in inner cities. Shipyards, naval installations, power stations and other sites where asbestos exposure is common may also have an increased risk to their personnel.

The peak in incidence is in the 6th and 7th decades of life as the risk is proportional to the total exposure to carcinogens in inhaled smoke. However, with more smokers starting the habit earlier in their teen years, cancers are being found in younger patients. The true incidence may be underestimated as many elderly patients unfit for any radical therapy have not in the past been referred for full diagnostic procedures.