The Analog Potential in Cancer Chemotherapy in the United States and Japan S. K. Carter Northern California Cancer Program, 1801 Page Mill Road, Building B, Suite 200, USA - Palo Alto, CA 94304 The bilateral collaborative program in cancer research between Japan and the United States is one of the oldest programs of this type. It is sponsored in the United States by the National Cancer Institute [1], while in Japan the sponsoring organization is the Japan Society for the Promotion of Science. Annual symposia concerning treatment have been held and in recent years they have been published [2, 3]. Drug development in both Japan and the United States has evolved over the years to an increasing emphasis on second generation compounds. This has come about as a result of the initial successes of chemotherapy development. Many active structures have been uncovered and the armamentarium of the medical and pediatric oncologist has grown dramatically. The uncovering of an active structure provides an opportunity for analog synthesis and attempts at elucidating structure-activity relationships. It is hoped that the therapeutic index of active structures can be improved so as to achieve superior clinical results.

The scientific collaboration between the United States and Japan in the field of cancer goes back many years. In this successful international collaboration cancer chemotherapy has been one of the most productive areas. Pioneers such as YOSHIDA, UMEZAWA, SHEAR, and GOLDIN established firm links of mutual trust and respect in the period after the Second Great War. Japanese drugs, such as mitomycin C and bleomycin have become mainstays of clinical oncology in the U. S. and throughout the world. Many drugs developed in the U. S. have become established in Japanese cancer therapy. Within the cancer chemotherapy field the antitumor antibiotics rank as one of the most important groups. In the U . S. -J apanese collaboration this group of drugs has taken the paramount role. The Japanese, under the leadership of U mezawa, are considered to be among the most innovative and productive in this area which has also had great emphasis in the United States as part of the National Cancer Institute's drug development program and in the pharmaceutical industry. This extended collaboration in general oncology, and chemotherapy in particular, has received increased impetus by and support from the official U . S. -J apan Joint Agreement on cancer research, which was established in 1974 between the National Cancer Institute and the Japanese Society for the Promotion of Science. One of the subsections of this agreement is cancer therapy with emphasis on chemotherapy.