In 1969, Li with Joseph F. Fraumeni, Jr. identified 24 families with a high risk of cancer throughout generations of family members. Their research and discovery in the abstract of Li and Dr. Fraumeni's paper described their method and results as, "A search of the Cancer Family Registry of the NationalCancer Institute revealed 24 kindreds with the syndrome of sarcoma, breast carcinoma, and other neoplasms in young patients. Cancer developed in an autosomal dominant pattern in 151 blood relatives, 119 of whom were affected before 45 years of age. These young patients had a total of 50 bone and soft tissue sarcomas of diverse histological subtypes and 28 breast cancers. Additional features of the syndrome included an excess of brain tumors, leukemia, and adrenocortical carcinoma before age 45 years. These neoplasms also accounted for 73% of the multiple primary cancers occurring in 15 family members. Six of these patients had second cancers linked to radiotherapy. The diversity of tumor types in this syndrome suggests pathogenetic mechanisms which differ from hereditary cancers arising in single organs or tissues. The syndrome is presently diagnosed on clinical grounds; laboratory markers are needed to identify high-risk individuals and families and to provide insights into susceptibility mechanisms that may be shared by a wide variety of cancers." Following these families for twenty years along with the 1990 discovery of inherited p53 gene mutations led to these mutations as being linked to causing Li-Fraumeni Syndrome. The p53 gene is known as the tumor suppressor gene.
Research Interests
of Hereditary Cancers
In his bio on the Harvard T.H. Chan School of Public Health website, Dr. Li said about his interests and work that "recent data have established that the basic molecular defects in cancer are genetic changes that result in loss of normal cellularcontrol mechanisms. Some of these mutations can be inherited through the germline. I have been studying inherited susceptibility of cancer through affected families. The goal is to identify genes that are involved in cancer development. I was attracted to studies of cancer families because epidemiological studies show that virtually all cancers manifest a tendency to aggregate in families. Close relatives of a cancer patient are at increased risk of that neoplasm, and perhaps other forms of cancer. The excess site-specific cancer risk is exceptionally high for carriers of certain cancer genes, in whom the attack rate can approach 100 percent. In candidate cancer families, the possibility that clustering is on the basis of chance must be excluded through epidemiological studies that establish the presence of an excess cancer risk. Predisposed families are candidates for laboratory studies to identify the inherited susceptibility factors. These investigations have led to the identification and isolation of human cancer genes, the tumor suppressor genes. These cancer genes are among more than 200 single-gene traits associated with the development of cancer. Approximately a dozen inherited susceptibility genes have been definitively identified, and many more are being sought. From studies of retinoblastoma and other rare cancers, important new information was generated about the fundamental biology of cancers that arise in many patients. Isolation of an inherited cancer susceptibility gene provides opportunities for presymptomatic testing of at-risk relatives. However, testing of healthy individuals also raise important issues regarding informed consent, confidentiality and potential for adverse psychological, social and economic effects...My colleagues and I are using families with inherited mutations in the p53 gene, which predisposes to breast cancer and diverse childhood cancers, as a model for developing a genetic testing program."