Dr. Odunsi is a leading expert in the development of vaccine-based treatments for gynecologic cancers (e.g., cervical and ovarian cancers).

Dr. Odunsi earned his medical degree from the University of Ife in Nigeria and his Ph.D. from the Weatherall Institute of Molecular Medicine at Oxford University. He completed additional training in obstetrics and gynecology, first at the University of Cambridge, and then at Yale. He also completed a fellowship in gynecological oncology at Roswell Park. He joined the staff there in 2001. Currently, he is the Chair of Gynecological Oncology, the Executive Director of the Center for Immunotherapy, and holds professor positions at both Roswell Park and the Medical School of the University of Buffalo.

Family history of ovarian cancer is still the most accurate predictor of who will go on to develop the disease, emphasizing the importance of genetic factors. Mutations in BRCA1 and/or BRCA2 are strongly associated with breast and ovarian cancer, with a number of specific variants identified that predict risk and treatment success. However, while we know a lot about BRCA1/2-associated ovarian cancers, only a small fraction of affected women fall into this category. The majority are thought to arise “spontaneously,” by some other mechanism.

In a recent paper, Dr. Odunsi and colleagues took advantage of Roswell Park’s Familial Ovarian Cancer Registry, which has been collecting data since 1981. It has been noticed that the sisters of a woman with ovarian cancer are at higher risk than their mother. In this paper, the authors argue that this could be explained if the cancer-causing mutation is coming from the father: they studied 3,500 grandmother-granddaughter pairs with ovarian cancer, and showed that the granddaughters were twice as likely to get ovarian cancer if the father’s mother had ovarian cancer than if the mother’s mother had ovarian cancer. Women who inherited the cancer from the paternal grandmother also tended to develop cancer at a younger age.

This phenomenon can be explained by the existence of a dominant risk-factor gene on the X chromosome. Women inherit a copy of the X chromosome from each parent, while men inherit an X chromosome from mom and a Y chromosome from dad. Thus, one of the granddaughter’s two X chromosomes must come from her father’s mother. The paternal grandmother has a 50% chance of passing on the X carrying the cancer-causing mutation to her son, who must pass it along to all of his daughters (total: 50% chance of granddaughter getting cancer). In contrast, the maternal grandmother has a 50% chance of passing a cancer-causing mutation to her daughter, but the daughter also has a 50% chance of passing it on to the granddaughter (total: 25% chance).

By looking at a large number of families, they were able to identify a possible gene on the X chromosome that might be responsible for this pattern of ovarian cancer inheritance.