[New discoveries in experimental cancer]

This 7th International Symposium organized by the National Academy of Medicine on New directions in cancer management, was sponsored by IUCC (International Union against Cancer) and received important financial assistance from the Fritz Bender Foundation. In 1996 and 97, the first two Symposia also dealt with cancer, specifically with tumor immunology and with the relation of human breast cancer with MMTV (murine mammary tumor virus). The aim of these introductory remarks is to emphasize recent breakthroughs related to these two subjects, which are also those of my laboratory. Although with inhibitors of angiogenesis it had been possible to block neovascularization without, however, attacking the tumor, recently the addition of low but continuous chemotherapy, so-called "metronomic therapy", has led to the reabsorption of established tumors. On the other hand, MMTV homologous viral sequences are being detected in human mammary tumors along with occasional viral particles. Moreover, a correlation has been encountered between the presence of Mus domesticus and a high incidence of human breast cancer in Occident and its absence in Orient where there is a low incidence of this cancer. It is to be hoped that new breakthroughs--or even conclusions from this meeting--will keep adding data towards finding solutions to the difficult problem of cancer.