PROGRAM AREA REPORTS

ANALYTICAL EPIDEMIOLOGY PROGRAM

The main program emphasis of the Analytical Epidemiology Program Area was directed toward the comparative epidemiology of cancer in the U.S. and Japan and a mutual program in approaching data on the occurrence and risk factors of childhood cancer in Japan and the U.S. Special emphasis was placed on the desirability of comparison of county maps for cancer mortality between two countries to develop hypotheses for the cause of certain types of cancer.
A U.S. biostatistician from the National Cancer Institute (NCI) was sent to Japan to observe the situation of biostatistics in cancer research in Japan. The manpower needs in biostatistics and epidemiology were stressed.
Epidemiologists and clinical etiologists from Japan and the United States attended a seminar in Orlando, Florida, in December 1975. This seminar was mainly concerned with priority cancer sites and problems in the U.S.-Japan Cooperative Cancer Research Program with special emphasis on the collection of data on “precious cases” for cancer epidemiology.
A “Workshop on Cancer Epidemiology” was held in Tokyo in October 1976. The participants were from various areas of cancer research, epidemiology, and statistics. As a result of the exchange of morbidity and mortality tables and charts, a monograph on Comparative Epidemiology of Cancer in the U. S. and Japan: Mortality was edited by Dr. Hirayama. The monograph showed the comparison of cancer mortality by age, sex, and anatomic site among the Japanese, American whites, and American blacks.
Some of the highlights observed by this comparison included: (1) a similar downward trend of cancer of the stomach and cervix in Japan and the U.S., although striking differences exist in the levels of rates; and (2) a rapid increase in death rates in Japan for cancer of the colon, pancreas, lung, breast, corpus uteri, ovary, prostate, testis, urinary organs, thyroid, multiple myeloma, and leukemia.
Topics that were discussed at the October 1976 Workshop in Tokyo were the review of recent developments in the etiology of childhood cancer with special reference to mortality rates by type in Japan, and discussions on the contrast in origins of leukemia, bladder cancer, and uterine cervical cancer. The discussion on the contrast of the etiologies of these cancers revealed different modes of origin, and new approaches were suggested on laboratory, chemical, and epidemiologic research in the future.
The exchange of selected scientists has been particularly productive during 1976 and 1977. From Japan, researchers in the field of clinical oncology, chemical carcinogenesis, and viral carcinogenesis were sent to the U.S. with the task of studying selected problems of epidemiologic interest (e.g., relationship with herpes type-2 and cervical cancer or mutagenesis of cigarette smoke condensate).
An American biostatistician spent several weeks in Japan and proposed closer coordination between biostatisticians and epidemiologists in Japan. As a result, a meeting is to be held in Hiroshima in May 1978 to discuss this matter in depth. It is expected fields of mutual interest will be found and will hopefully serve as the basis of increasing manpower, especially in statistical-epidemiologists, who are in extreme shortage in Japan.
Future program plans include a meeting on biostatistics being planned for May 1978, at which invited mathematicians, statisticians, and epidemiologists will discuss the present status and future needs for studies on cancer epidemiology, with special reference to the value of application of newly developed statistical methods. Problems related to manpower, education, training, and also desirable job structure in both countries will also be discussed.
The publication of a monograph Comparative Epidemiology of Cancer in the U.S. and Japan: Morbidity, which is a sequel to the previous publication Mortality, is in progress. Differences in the incidence pattern of sites of cancer in Japan and in the U.S. will be summarized. These differences may be due to environmental factors and nutritional patterns. Such analysis will be fruitful for the study of etiologic factors of each site of cancer.