Although the incidence of borderline ovarian tumors may not be increased in HBOC syndrome kindreds and those who carry cancer-associated BRCA1 and BRCA2 mutations, these individuals could be susceptible to malignant transformation of borderline lesions of the ovaries and peritoneum.
These results suggest that inactivation of the BRCA1 gene may not be responsible for the development of borderline ovarian tumors and that another tumor suppressor gene, located centromeric to the BRCA1 gene, may play a role in sporadic ovarian cancer development.