[3] Lynch was the chairman of preventive medicine at Creighton University School of Medicine in Omaha, Nebraska and held the Charles F. and Mary C. Heider Endowed Chair in Cancer Research.
[6] He persisted, compiling data and statistics that demonstrated patterns of "cancer syndromes" through multiple generations of families.
He defined the necessary criteria for a genetic cancer: early age of onset of the disease, specific pattern of multiple primary cancers, and Mendelian patterns of inheritance in hundreds of extended families worldwide.
[6] Under his leadership Creighton also hosts a High Risk Registry, part of the Early Detection Research Network sponsored by the National Cancer Institute.
[7] The Registry allows the Network to educate individual patients about their genetic risk status.