title: Loss of heterozygosity at the BRCA1 and BRCA2 loci detected in ductal lavage fluid from BRCA gene mutation carriers and controls.
abstract: Female BRCA gene mutation carriers are at increased risk for developing breast cancer. Ductal lavage is a novel method for sampling breast ductal fluid, providing epithelial cells for cytologic assessment and a source of free DNA for molecular analyses. Loss of heterozygosity (LOH) at the BRCA loci in ductal lavage fluid is a potential biomarker of breast cancer risk. The LOH rate was measured at the BRCA1/2 loci and compared with that at a control locus (APC) using free DNA from the ductal lavage fluid of BRCA carriers and predictive test negative controls. We evaluated the reproducibility of these analyses. Free DNA sufficient for PCR amplification was obtained from 33 ductal lavage samples of 17 healthy women of known BRCA status (14 BRCA carriers and 3 controls). LOH rates of 36.4% to 56.3% at the BRCA1 locus and 45% to 61.5% at the BRCA2 locus were found among BRCA carriers. The LOH rate at the APC locus was lower (18.5%). The interaliquot reproducibility for the D17S855 marker of the BRCA1 locus was 66.7%. Intraaliquot reproducibility was 90%. Although we successfully isolated sufficient free DNA from ductal lavage fluid for PCR amplification, the degree of reproducibility of these LOH studies raises questions about the robustness of this technique as a risk assessment tool in the evaluation of high-risk women. Further studies are required to evaluate the specificity and predictive value of LOH in ductal lavage fluid for breast cancer development.
authors.affiliation: The Institute of Cancer Research, London, UK. imogen.locke@icr.ac.uk
authors.forename: Imogen
authors.initials: I
authors.lastname: Locke
authors.forename: Zsofia
authors.initials: Z
authors.lastname: Kote-Jarai
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bancroft
authors.forename: Sarah
authors.initials: S
authors.lastname: Bullock
authors.forename: Sarah
authors.initials: S
authors.lastname: Jugurnauth
authors.forename: Peter
authors.initials: P
authors.lastname: Osin
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Nerurkar
authors.forename: Louise
authors.initials: L
authors.lastname: Izatt
authors.forename: Gabriella
authors.initials: G
authors.lastname: Pichert
authors.forename: Gerald P H
authors.initials: GP
authors.lastname: Gui
authors.forename: Rosalind A
authors.initials: RA
authors.lastname: Eeles
mesh_terms: D000328:Adult; D001826:Body Fluids / Q000166:cytology*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000473:pathology; D016022:Case-Control Studies; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D018095:Germ-Line Mutation; D006579:Heterozygote; D006801:Humans; D019656:Loss of Heterozygosity; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D007507:Therapeutic Irrigation
chemical_list: D004247:DNA