The term breast-ovarian cancer (BOC) refers to families in which individuals have suffered from breast cancer and ovarian cancer (either one individual suffered from both, or several individuals in the pedigree suffered from one or the other disease). Physicians, and especially genetic counselors use the term hereditary breast-ovarian cancer (or HBOC) to refer to a family in which they suspect a hereditary factor to cause the pattern of breast and ovarian cancer occurrences in the family.
In these kind of families, two genes have been found, in which mutations can cause this pattern of inherited breast and/or ovarian cancer. These genes are BRCA1 and BRCA2. However, not in all families in which HBOC is suspected, a mutation in either BRCA1 or BRCA2 can be found.