Pedigree identifies hereditary breast cancer syndromes

Clinical Question

Does a simple pedigree scoring tool identify women at increased risk of hereditary breast cancer syndromes?

Bottom Line

A simple pedigree scoring tool can identify women at increased risk of mutations of BRCA1 and BRCA2. Since this tool doesn't report the actual BRCA status, however, it is of limited use until these data become available. Nonetheless, these women should be counseled about their increased risk and their options: genetic counseling, testing, and consideration of chemoprophylaxis, prophylactic oophorectomy, prophylactic mastectomy, and so forth. (LOE = 2c)

Reference

Hoskins KF, Zwaagstra A, Ranz M. Validation of a tool for identifying women at high risk for hereditary breast cancer in population-based screening. Cancer 2006;107:1769-1776.  [PMID:16967460]

Study Design

Cross-sectional

Funding

Foundation

Setting

Outpatient (any)

Synopsis

More than 3900 women presenting for mammograms completed a questionnaire that included items to calculate a Gail score and a pedigree assessment tool score. The Gail score is based on a risk model that estimates a woman's 5-year and lifetime risk of developing breast cancer (www.cancer.gov/bcrisktool/) and is used to determine a woman's eligibility for chemoprophylaxis and as a basis for referral for genetic counseling. The pedigree assessment tool assigns points for each family member with specific criteria: breast cancer at 50 years or older (3 points); breast cancer before age 50 years (4 points); ovarian cancer at any age (5 points); male breast cancer at any age (8 points); and Ashkenazi Jewish heritage (4 points). The pedigree tool is applied to (maternal and paternal) first-, second-, and third-degree relatives. If a patient had a 5-year Gail estimate of 1.7% or higher, a lifetime risk greater than 15%, or had any family member with breast or ovarian cancer, the patient was then evaluated using a genetic risk assessment tool that classified patients as being at low or high risk of having a mutation of BRCA1 or BRCA2. The authors identified 737 women to undergo this additional risk assessment: 651 were at low risk and 86 were at high risk of BRCA1/BRCA2 mutations. The authors identified a pedigree score of 8 or higher as the optimal cutoff to identify women at high risk of genetic mutations. They were unable to identify a 5-year Gail score with acceptable performance characteristics; the only cut-off point values with more than 50% sensitivity had a maximum specificity of 10%. Based on the area under the receiver operator characteristic curve, the pedigree assessment tool correctly classified women 96% of the time compared with 39% for the 5-year Gail score and 59% for the lifetime score.