BRCAPAP: Feasibility of clinical BRCA testing on liquid-based cervical cytology: Implications for biomarker development

Abstract

Objective: The study was designed to test the feasibility that lower genital tract cytology is a compatible medium for robust germ line genetic analyses. Method: BRCA1 and/or BRCA2 gene mutational analysis was done on DNA isolated from liquid-based cervical or vaginal cytology taken from 17 consenting women (age 29-65 years) who previously had genetic counseling followed by BRACAnalysis (Myriad Genetics, Salt Lake City, UT) blood analyses. Eleven women had known mutations in either BRCA1 or BRCA2 (cases) and six had no identified mutations (controls) on entry into the study. Anonymized cytology samples were sent to Myriad Genetics with a request for testing that was limited to the degree of genomic testing previously done on the blood samples. Results: One cervicovaginal specimen from a test-positive woman had inadequate cellular content that precluded gene sequencing and therefore was excluded from this analysis. For the 16 women with adequate cytologic specimens, there was 100% concordance for BRCA mutation test results between blood and genital tract cytology (κ = 1.0; 95% confidence interval, 0.51-1.0). Conclusion: We have shown the feasibility of using liquid-based genital tract cytology as an alternative biospecimen to blood for germ line genetic analysis using a clinical approved assay. It needs to be emphasized that any type of testing for BRCA1 or BRCA2 mutation genotype should only be done in the setting of pretest and posttest counseling.