Accuracy of the BRCAPRO model among women with bilateral breast cancer.
BACKGROUND
The likelihood of identifying a BRCA mutation was often calculated using the BRCAPRO model. A previous study suggested that this model may overestimate the chance of detecting a BRCA mutation among women diagnosed with bilateral breast cancer. Studies also suggested that few patients with bilateral breast cancer whose age at first diagnosis is >40 years were mutation carriers. The objectives of this study were to determine the accuracy of the BRCAPRO model among women with bilateral breast cancer and to determine whether their mutation status was dependent on their age at first diagnosis.


METHODS
A retrospective chart review was performed. Women who were diagnosed with bilateral or unilateral breast cancer and who had undergone comprehensive BRCA1 and BRCA2 genetic testing at M. D. Anderson Cancer Center between 1997 and 2006 were included in the study.


RESULTS
For individuals with pre-test carrier probabilities >31%, the proportion of positive tests was significantly lower than predicted by the BRCAPRO model (P < .05). In addition, the carrier rate of BRCA mutations was significantly higher (P = .002, Fisher exact test) in women with bilateral breast cancer whose age at first diagnosis was <or=40 years compared with those diagnosed >40 years.


CONCLUSIONS
The BRCAPRO model was overestimating the relative contribution bilateral breast cancer had on the likelihood of detecting a BRCA1 or BRCA2 mutation. Bilateral breast cancer did not appear to be a good indicator of mutation status, particularly for women whose age at first diagnosis is >40 years.
Ready
Kaylene J
KJ
University of Texas M. D. Anderson Cancer Center, Department of Breast Medical Oncology, Unit 1354, P.O. Box 301439, Houston, TX 77230-1439, USA. kready@mdanderson.org
Vogel
Kristen J
KJ
Atchley
Deann P
DP
Broglio
Kristine R
KR
Solomon
Kimberly K
KK
Amos
Christopher
C
Lu
Karen H
KH
Hortobagyi
Gabriel N
GN
Arun
Banu
B
D000328:Adult; D000368:Aged; D019313:BRCA1 Protein / Q000235:genetics*; D024682:BRCA2 Protein / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000601:surgery; D003198:Computer Simulation; D005260:Female; D007839:Functional Laterality; D005817:Genetic Counseling; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006801:Humans; D008875:Middle Aged; D015233:Models, Statistical; D009154:Mutation / Q000235:genetics*; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult
D019313:BRCA1 Protein; D024682:BRCA2 Protein