PROGRAM AREA REPORTS

METASTASIS PROGRAM

The Metastasis Program Area has continued to make efforts to acquaint American and Japanese scientists active in this specialized field of cancer research with current research activities. Accomplishments during this two-year period include very productive seminars which led to exchange visits among leading scientists from both countries.
A program initiated “Workshop on Metastasis” was held in Kona, Hawaii, in May 1976, with eight Japanese and ten American scientists participating. The purpose of this Workshop was to conduct a broad survey of the field of metastasis from both the basic and clinical levels. The practical and theoretical efforts of the Japanese in this field were appreciated as were some novel experimental approaches on the part of the Americans. This may have been due, in part, to the heterogeneous backgrounds of the participants; more cell biologists among the Americans and more pathologists and clinicians among the Japanese.
The proceedings, Cancer Metastasis: Approaches to the Mechanism, Prevention, and Treatment, were published as GANN monograph No. 20, 1977. Some highlights of the report include: biological backgrounds of metastasis, such as preferential tissue trapping of tumor cells, factors involving cell separation and cell adhesion; in vitro and in vivo experimental models for study of metastasis; host defense mechanisms, such as immune and thromboplastic reaction; experimental and clinical inhibition of metastasis by sulfated polysaccharides; treatment of metastasis by lipid emulsions or liposomes including anticancer agents; effects of radiation and chemotherapy on metastasis; treatment of lung metastasis by sulfated polysaccharides; and other novel combined methods of treatment of metastasis.
Throughout the meeting, new concepts regarding the metastatic process and new approaches to investigate metastasis emerged. In addition, it was decided at this meeting to include some of the noted Japanese presentations at the International Workshop on Metastasis to be held in New York in late 1976.
Through the communication channels of such activities under the U.S.-Japan Cooperative Cancer Research Program, Japanese investigators were invited as active participants to the “International Workshop on Cancer Invasion and Metastasis: Biologic Mechanisms and Therapy,” held in New York on November 29 to December 1, 1976, and sponsored by the Sloan-Kettering Cancer Institute, Mario Negri Institute (Milano), and the National Cancer Institute. Japanese scientists who participated in this workshop were sponsored by the Division of Cancer Research Resources and Centers (DCRRC), NCI. The proceedings were published as Volume 5 in the series Progress in Cancer Research and Therapy (Raven Press, 1977).
A particularly notable event that occurred during this two-year reporting period was the visit by two American scientists to eight research centers and medical institutions in Japan. The purpose of their visit was to critically review present programs and to propose future programs. They actively participated in the lectures, seminars, and informal discussions and reported that most professional staff working on metastasis research in Japan are either surgeons or pathologists who carry out research in an informal situation with very few technicians. Much of their work is still published only in Japanese journals and does not receive the full publicity it deserves. The two American scientists felt that communication among the Japanese scientists was a problem and they even spent some time modifying several English-language draft manuscripts to facilitate submission to American cancer journals. The American visitors reported that the Metastasis Program Area did provide a useful vehicle for information exchange between the researchers of the two countries. After considering the substantial body of work available in both countries, it was proposed that a future workshop should concentrate on such a specific topic as “New Approaches to Therapy of Established Metastasis,” focusing on “adequate animal models.” This proposal has been considered by the program coordinators, and a seminar for 1978 is being planned along this line.
Because of the obvious success of the two American scientists’ visit to Japan, and the personal influence to the scientists of their counterpart country, exchanges such as this are enthusiastically encouraged.
Future plans include a seminar on the “Fundamental and Clinical Basis for Treatment of Micrometastasis” to be held in Nara, Japan, in October 1978.