The chief difficulty of determining the relative frequency of carcinoma in different parts of the globe is due to the extraordinary deficiency of trustworthy observations. In many instances our sole information upon the subject is derived from the general impressions of some explorer more or less versed in medical matters, while in not a few cases dogmatic inferences have been drawn from the experiences of a single individual extending over a very limited period. Thus it is the custom to state that cancer of the stomach is very rare in Vera Cruz, because Heinemann happened to see only one example of the complaint during a residence of six years in that city; while its supposititious infrequency in Japan has been founded upon the equally limited experience of Schulze. When one considers how many medical men in the rural districts of England, and even in London, must fail to meet with a case of gastric cancer during the first six years of practice, it appears almost incredible that such worthless statements should ever have been regarded as worthy of notice.
As far as our present knowledge extends, carcinoma may be said to exist among all the civilised nations of the globe. In Great Britain, France, Spain, Germany, Austria, Italy, Russia, and Norway, it is not only rife but increasing in frequency. In Denmark it appears to be especially prevalent, and the same remark applies in a lesser degree to Switzerland. In Turkey and Greece it is said to be less common (Rigler, Roser), while in Iceland it is described as rare (Finsen). Speaking generally, Continental statistics indicate a much greater frequency of gastric carcinoma than those of Great Britain. The United States and Canada exhibit an ever-increasing mortality from cancer, and there is evidence to show that it is by no means infrequent in South America (Bey, Gayraud and Domec, Jourdanet).
Northern Africa, including Egypt, Tunis, Algiers, and Abyssinia, is supposed to enjoy a special immunity from the complaint ; but south of the Zambesi it is stated by competent authorities to be extremely frequent. Syria, Persia, and Arabia, like other countries where accurate observations are lacking, are said to be comparatively free from cancerous diseases (Polak, Palgrave), while in most parts of India the reverse is the case. According to Hobson, carcinoma in all its forms is frequently met with in China; but medical missionaries who have travelled in the interior of that country have assured us that cancer of the stomach is very rare.1 Its prevalence in Australia and New Zealand has already been commented upon.