Document VjXrOg5g4ka9xpbEKpGV5nO6w

CANCERS OF THE RESPIRATORY SYSTEM 385 pational cancers of the lung in man and with spontaneous and experimental pulmonary tumors of mice suggest that the advent of new and powerful exogenous carcinogenic agents at the end of the last century might be pre supposed, if the increase in the frequency of pulmonary malignancy would have been accompanied by a shift of the manifestation time into younger age groups. On this point the following information is available in the literature. In a series of 44 cases observed by Ask-Upmark, between 1890 and 1930, the age range for men with lung cancer was 30-76 years (average 51 years) and for women 43 to 66 years (average 56.5 years). In.the series of 60 carci nomas seen between 1923 and 1933, of which 74.5 per cent occurred in males, Haintz reported an age range of 36 to 70 years (average 56 years). A more detailed analysis of the age distribution of their 202 cases, observed between 1922 and 1926, was given by McCrae, Funk and Jackson. Their data are presented in the following table: Years 16-30 Cases Percentage 6 3 31-40 29 15 41-50 49 26 51-60 65 35 61-70 34 18 70 and more 6 3 In connection with his survey of lung cancer among the American veterans, Matz published the table on page 386 compiled from the data of 8 investigators reporting 1,814 cases. ' The age correlation in Matz's own series of 138 cases, occurring between 1927 and 1937 in American war veterans, showed a definite shift toward younger age groups. He attributed this fact to the younger average age of the veterans compared with that pf the civilian population. He anticipated an increasing incidence of pulmonary malignancy among the veterans in the coming years as they approach the higher age groups. Years Percentage Age Incidence of Bronchiogenic Carcinoma-Matz 20-29 3~39 4~49 5~59 60-69 1.4 25.4 48.6 18.8 5.1 70 and over 0.7 The data, contained in the collective statistics of Matz, are in general agreement with those obtained by Simons on an even larger series of cases (2,786). Simons observed that 22.4 per cent of them were found in the age group 41-50 years, 34 per cent in the age group 51-60 years, and 24 per cent in the age group 61-70 years. In all, 80 per cent occurred in persons between 40 to 70 years old, and only 14 out of 5,217 cases were younger than 20 years. The data available do not supply any reliable and comprehensive informa tion from which a chronological analysis of the age distribution of lung cancer, during the last five decades, can.be made. No conclusion can be drawn regard ing the question as to whether or not pulmonary cancer in recent years became manifest more often at an earlier age than in former times.