CARCINOMA OF THE LUNG: THE CHANGING PATTERN OF MORTALITY IN ONTARIO

Study of the mortality rates for carcinoma of the lung in men in Ontario between 1931 and 1959 reveals a rise from 3.7 in the early 1930's to 26.7 per 100,000 in the late 1950's. Analysis of age-specific mortality rates in five-year cohorts (groups of men born within five-year periods) shows that (1) mortality rates in each cohort rise rapidly after the age of 40, ascending in the later years of life almost as a straight line; (2) each succeeding cohort experiences an appreciably higher mortality rate than the preceding one. Mortality rates in individual cohorts in Ontario are compared with those in England; the shape of the cohort curves, and the rate of the increase in mortality from cohort to cohort, are almost identical. However, the picture in Ontario appears to be lagging some 10 years behind. The mortality rates for men in Ontario born around the year 1890 are almost identical with those shown by men born in England around 1880. The rates for carcinoma of the lung will almost inevitably continue to rise in Ontario for at least the next 10 to 20 years.