Other organizations and institutions with overlapping interests participate in many INCTR activities. Such participation entails joint conduct of projects, or the provision by other organizations of specific elements relevant to the INCTR program, for example training and education, the conduct of specific research, the preparation of guidebooks or training manuals, the transfer of technology, or the development of policy.

Because of its internal structure and the origin of its support, the INCTR has strong links with the International Union Against Cancer (UICC), the Institut Pasteur, Brussels, and the National Cancer Institute (NCI) of the USA. It continues to extend its professional network with other governmental agencies, including the World Health Organization (WHO), the International Agency for Research on Cancer of the WHO, with the PACT Program of the International Atomic Energy Agency, with non-governmental organizations, with universities and with the corporate world.