Ask the Physician: Dr. Nadine Tung, MD
Question from Len in Newton, MA
"Is '1 in 40' the average likelihood of having a BRCA gene mutation for Ashkenazi Jews? Neither my wife nor I have any known family history of the associated cancers. Does that mean our odds are lower than 1 in 40? If someone does have a family history of certain types of cancers, I would assume their odds are higher. True?"
Response from Dr. Nadine Tung, MD
Director, Breast Medical Oncology
Beth Israel Deaconess Medical Center
"That is true. One in forty is an average. If someone has a family history of breast cancer or ovarian cancer, for example, the risk would be higher. Likewise, for someone who has no family history the likelihood might be lower. It is worth remembering though, that the larger a family is, with more women on both sides of the family, the more a lack of family history of cancer is meaningful. However, unless someone has an extremely large family, it is hard to be completely reassured by a lack of cancer in the family. Several studies have shown that for Jewish men and women, half of the BRCA mutations detected are in individuals who did not think they had a family history of breast or ovarian cancer. That may be due to small families, or lack of knowledge about family history."
Submit your questions for this column to firstname.lastname@example.org