Age

As regards the age at which gastric cancer occurs, Brinton collected 600 cases, the ages of which at death averaged 50 years. The greater part (three-quarters, or 435) of these 600 cases fell in the epoch of life between 40 and 70. Arranged in decades of years, the maximum number (two-sevenths, or 162) occurred between 50 and 60. Comparing these numbers with the number of persons living in these decades of life, an estimate of the relative liability of the corresponding ages to the malady is obtained. Brinton gives the maximum liability between 60 and 70. Up to the age of 20, the whole risk is less than one-fiftieth of what it reaches between 20 and 30. The latter liability is multiplied in the following decades of years by 3, 6, 8, and 10 respectively. The maximum then seems to sink to little more than half for the next two decades, ending at the extreme age of 100. With reference to age, Lebert gives the following figures in his statistics: Under 30 years, 1 per cent; 30 to 40 years. 17.6 per cent; 40 to 60, 60.7 per cent; 60 to 70, 16.3 per cent; above 70, 4.4 percent.

Welch's statistics of 2,075 cases of gastric cancer show the following distribution for the different ages: 10 to 20, 2; 20 to 30, 55; 30 to 40, 271; 40 to 50, 499; 50 to 60, 620; 60 to 70, 428; 70 to 80, 140.

According to all these statistics, the maximum liability of gastric cancer lies between the fortieth and sixtieth year. It is very rare before the thirtieth1 however, each mention a case in which the disease was congenital. M. Mathieu 2 has collected all the cases of gastric cancer below the thirtieth year mentioned in literature, and the number was 27. Debove3 recently published a case of gastric cancer in a young man of 24 years, and I observed a similar case in a man of 27 years two years ago. In this latter case the disease was verified by an operation.

1Heinemann: Virch. Arch., vol. 38, p. 180 year. Both Wilkinson and Wiederhoefer.

Sex

The influence of sex is far more difficult to estimate than that of age. Brinton mentions 784 cases, of which 440 were males and 344 females. Fox's4 tabulation of the statements of seven writers shows that of 1,303 cases 680 were males and 623 females. Of Welch's 2,214 cases, 1,233 were men and 981 women.

These figures show a higher percentage for men than women, but this statement is not of necessity absolutely true, for the larger percentage of cancer among men may result from the larger number of male patients treated in the hospitals from which these statistics have been obtained.

Heredity

Most writers concur that in some families several members are found to be afflicted with cancer, and are inclined to attribute this fact to heredity. Every physician has observed cases in which the father and one or two sons had been troubled with cancer. In some instances there is a history of cancer in the parents, relating perhaps to some organ other than the stomach. Cancer being such a frequent malady, however, it is quite difficult to state whether these occasionally observed facts are sufficient to prove that heredity plays an important part, or whether it is a mere coincidence. Statistical figures on this point are given by Lebert and Haeberlin. The former found an hereditary history in 7, the latter in 8 per cent. Snow found among 1,075 cases of cancer in different parts of the body, 176 cases, or 15.7 per cent, in which cancerous disease had existed in the family.

1 Cited from Eichhorst: "Lehrbuch der spec. Path, und Therapie".

2Max Mathieu: Gaz. des Hopit, 1884, p. 118.

3 Debove: Societe med. deshopit. November, 1889.

4 Fox: "The Diseases of the Stomach," London, 1872, p. 184.