Fluorescence in situ hybridization of ductal lavage samples identifies malignant phenotypes from cytologically normal cells in women with breast cancer

Abstract

BACKGROUND. Ductal lavage (DL) does not routinely identify cytologically malignant cells. For this study, the authors asked whether molecular analyses of DL specimens from women with cancer would identify abnormal cells, even if they appeared cytologically normal. METHODS. DL was performed and yielded fluid in 29 of 45 consenting women who were undergoing breast cancer surgery. Array comparative genomic hybridization (CGH) was performed on the corresponding tumor tissue from 14 women. There was no single, common alteration; thus, bacterial artificial chromosome‐specific fluorescence in situ hybridization (FISH) probes were selected based on CGH alterations. RESULTS. FISH copy number changes were detected in tumor sections in 9 women. In the corresponding 9 DL samples, 1 sample was clearly malignant on cytology, 1 showed marked atypia, 1 showed mild atypia, and the rest were benign. Five of the 9 DL samples had epithelial cells that showed genetic changes identical to those observed in the tumor by FISH. The remaining 4 of 9 DL samples that did not show molecular changes were probably (N = 1) or possibly (N = 3) from the same duct as the tumor. CONCLUSIONS. Although only 11% of the DL samples were identified as malignant cytologically, 55% showed molecular changes that were identical to those observed in the tumor. FISH was more sensitive for finding tumor in DL specimens than cytology. However, the ductal system in which the tumor was located did not always yield fluid, limiting the sensitivity of DL. The results from this study showed that genetic changes can be detected in the absence of morphologic changes in cytologically benign cells, but the application will be limited without a better approach for acquiring cells and a common set of probes for detecting molecular abnormalities that are found in breast malignancies. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.

Ductal Lavage of Cancerous and Unaffected Breasts

“…In fact, prior publications with higher rates of suspicious or malignant cells contained greater percentages of women with DCIS. 21,23 At least 2 groups have shown that random FNA (rFNA) is associated with greater success with respect to cellular adequacy and cell yield. 24,25 Ozanne and Esserman 26 have demonstrated that rFNA is less costly than DL while others have shown rFNA to be very tolerable.…”

Status of Intraductal Therapy for Ductal Carcinoma in Situ

“…Although only 11% of cytology samples were characterized as malignant, 55% of samples showed biomarker changes that were identical to those found in the primary surgical specimen. This study clearly demonstrated the increased sensitivity of molecular probes over cytology for detection of malignancy in ductal lavage samples [32]. …”

“…The authors concluded that FISH-based detection of chromosomal aneuploidy could potentially be used as an adjunct to cytologic evaluation in confirming both benign and malignant diagnoses [31]. Adduci et al [32] utilized array-based comparative genomic hybridization (CGH) in primary surgical specimens then tested matched ductal lavage specimens with region-specific FISH probes to determine whether similar chromosomal alterations were present in both specimens. Although only 11% of cytology samples were characterized as malignant, 55% of samples showed biomarker changes that were identical to those found in the primary surgical specimen.…”

Breast Cytology: Current Issues and Future Directions

“…A sufficient amount of RNA can be made available from RPFNA samples for quantitative polymerase chain reaction (PCR) for 6 to 12 biomarkers [103] Recently, it has been shown that quantitative evaluation of DNA hypermethylation using methylation-specific PCR can be readily preformed on NAF and DL samples [104] These authors observed that methylation of CCND-2, p16, RAR-beta, and RASSF-1a was significantly more prevalent in tumor than in normal tissue specimens. In another study, using fluorescent in situ hybridization, chromosomal alterations identified in DL specimens obtained from women who underwent breast cancer surgery matched those identified in the corresponding resected breast cancers using comparative genomic hybridization [105]. Interestingly, only 10% of the DL samples were identified as malignant cytologically, whereas over half of the DL samples showed molecular changes characteristic of the tumor.…”