What percentage of patients with hereditary breast and ovarian cancer (HBOC) due to BRCA1 mutations also experience ovarian cancer?

In individuals with hereditary breast and ovarian cancer (HBOC) due to BRCA1 mutations, research indicates that approximately 40% of these patients will develop ovarian cancer by the age of 70. This statistic is significant in genetic counseling as it highlights the increased risk for ovarian cancer in those with BRCA1 mutations compared to the general population. Understanding this risk is crucial for both patients and their families, as it can influence screening recommendations and decisions regarding preventive measures.

The other percentages provided in the choices either overestimate or underestimate the risk based on the latest available data from clinical studies and cohort analyses. While BRCA1 mutations are strongly associated with ovarian cancer, the calculated risk does not reach the higher figures suggested by the other choices. Therefore, the correct answer reflects current epidemiological data and aids in conveying the seriousness of monitoring and preventive strategies for individuals with BRCA1-related HBOC.