Abstract: The historical perspective and the treatment of breast cancer are the oldest indications of its metastatic origin. The experimental background of the metastatic view comes from our chemically induced rat renal nephroblastoma and liver hepatocarcinoma tumors. The implantation of tumor cells of cell lines established from these primary tumors resulted in a kidney capsule – parathymic lymph node (PTN) metastasis model. India ink implantation also proved the lymphatic connection between the primary tumor of the kidney and PTNs. 18F-FDG glucose analog distribution in different organs provided evidence that the primary sites of tumor progression are PTNs. Tumor growth was also followed by staining sections of biopsies of normal, tumorous kidneys and PTNs. Tumor invasion turned to disruptions in the renal tissue, releasing cancer cells into the peritoneal cavity. Transdiaphragmatic channels drained tumor cells into thoracal lymphatics entering anterior mammary and parathymic lymph nodes. The kidney capsule-PTN complex is reflecting a so far unknown mechanism of tumor development and contributes to the understanding of tumor development in mammary lymph nodes. The model provides a reasonable explanation for breast cancer formation, that is viewed as a metastasis, rather than a primary tumor.

Brief biography of the speaker:
Gaspar Banfalvi has received his MS and PhD degrees from the School of Medicine, Szeged, Hungary, his D.Sc. from the Institute of Medical Chemistry, Semmelweis University Medical School, Budapest (1989), Venia Legendi in Biology at the University of Science, Szeged (1994), and Venia legendi in Medicine at the Semmelweis University, Budapest,1994. He has worked as Visiting Scientist and Associate Professor at Harvard Medical School, Boston, MA (1983-84, 1987-88) and Harvard University, Cambridge, MA (1994) on discontinuous DNA replication. At the Leiden University he was visualizing individual replicons by fluorescent immunfluorescent staining and confocal microscopy. He was a research faculty at the National Center for Toxicological Research working on replication and repair checkpoints (1996), as Meyerhof Visiting Professor in the Weizmann Institute, Rehovot, Israel doing research on base excision repair and chromatin condensation. In the first semester of the 2003/2004 academic year as a Visting Professor he was lecturer at the Teikyo University, Maastricht, the Netherlands. In 2000 as a professor he moved to Debrecen University. Recently he is working at the Department of Microbial Biotechnology and Cell Biology. His research involves permeabilization and regeneration of membranes, nucleic acid structure and function, mechanism of chromatin condensation, genotoxic effects related to replication, repair, mutation, apoptosis, malignant transformation. Recently his group has established several tumor cell lines after chemical tumor induction and is using the kidney capsule-parathymic lymph node complex as a suitable metastatic model.