Detection of microsatellite alterations in nipple discharge accompanied by breast cancer

Analysis of nipple aspirate fluid for diagnosis of breast cancer: an alternative to invasive biopsy

Over 40,000 women in the USA will die this year of breast cancer. Current generally accepted techniques to detect breast cancer are limited to breast examination and mammography. Abnormalities found by these techniques require an invasive needle or surgical biopsy to determine if cancer is present. The author's ultimate goal is to determine if a woman has breast cancer without the need for invasive biopsies, and do this before the abnormality is detectable by standard screening techniques. Herein, the technology is reviewed as it was, as it is today, and its future potential is discussed.

The intraductal approach to the breast: raison d'être

Opportunities for the detection, prediction, and treatment of breast cancer exist at three biological levels: systemically via the blood, at the whole organ level, and within the individual ductal lobular structures of the breast. This review covers the evaluation of approaches targeted to the ductal lobular units, where breast cancer begins. Studies to date suggest the presence of 5 to 12 independent ductal lobular systems per breast, each harboring complex cellular fluids contributed by local and systemic processes. New techniques for accessing and interrogating these systems offer the potential to gauge the microenvironment of the breast and distill biological risk profiles.

Genotoxicity of steroidal estrogens

The molecular mechanisms underlying the development of breast cancer in general, and estrogen-associated breast carcinogenesis in particular, are not completely understood. There are three mechanisms considered responsible for the carcinogenicity of estrogens in the human breast: (i) receptor-mediated hormonal activity, which stimulates cellular proliferation, resulting in more opportunities for accumulation of the genetic damage that leads to carcinogenesis; (ii) a cytochrome P450-mediated metabolic activation, which elicits direct genotoxic effects by increasing mutation rates; and (iii) the induction of aneuploidy by estrogen. In this article, we concentrate on discussing the role of estrogen receptors and the metabolic activation of 17beta-estradiol (E(2)) as mechanisms of breast cancer initiation.

A Review of Mammary Ductoscopy in Breast Cancer

Breast carcinoma and hyperplasia are thought to start in the lining of the breast duct. Mammary ductoscopy is an emerging technique allowing direct visual access of the ductal system of the breast through the nipple. This article reviews and discusses the utility of mammary ductoscopy. Abnormalities can be identified successfully by mammary ductoscopy, and intraductal biopsy can be used when the tumor is a polypoid type. Ductal lavage using microcatheters is effective in identifying malignant cells in high-risk women and this has stimulated interest in exploring the role of mammary ductoscopy in breast cancer screening. Mammary ductoscopy combined with ductal lavage may have a role in the management of patients with nipple discharge, the guiding of breast-conserving surgery for cancer, and in screening for high-risk women. The addition of molecular and genetic analysis of cells obtained by mammary ductoscopy are likely to enhance the use of this technique. Mammary ductoscopy techniques are safe and appear useful for detecting abnormalities in the breast. The additional molecular biologic study or ductal lavage may enhance the ability to direct and limit subsequent surgery when removing the offending lesions.

Estrogen and its metabolites are carcinogenic agents in human breast epithelial cells

Estrogens play a crucial role in the development and evolution of human breast cancer. However, it is still unclear whether estrogens are carcinogenic to the human breast. There are three mechanisms that have been considered to be responsible for the carcinogenicity of estrogens: receptor-mediated hormonal activity, a cytochrome P450 (CYP)-mediated metabolic activation, which elicits direct genotoxic effects by increasing mutation rates, and the induction of aneuploidy by estrogen. To fully demonstrate that estrogens are carcinogenic in the human breast through one or more of the mechanisms explained above it will require an experimental system in which, estrogens by itself or one of the metabolites would induce transformation phenotypes indicative of neoplasia in HBEC in vitro and also induce genomic alterations similar to those observed in spontaneous malignancies. In order to mimic the intermittent exposure of HBEC to endogenous estrogens, MCF-10F cells that are ERalpha negative and ERbeta positive were first treated with 0, 0.007, 70 nM and 1 microM of 17beta-estradiol (E(2)), diethylstilbestrol (DES), benz(a)pyrene (BP), progesterone (P), 2-OH-E(2), 4-hydoxy estradiol (4-OH-E(2)) and 16-alpha-OH-E(2) at 72 h and 120 h post-plating. Treatment of HBEC with physiological doses of E(2), 2-OH-E(2), 4-OH-E(2) induce anchorage independent growth, colony formation in agar methocel, and reduced ductulogenic capacity in collagen gel, all phenotypes whose expression are indicative of neoplastic transformation, and that are induced by BP under the same culture conditions. The presence of ERbeta is the pathway used by E(2) to induce colony formation in agar methocel and loss of ductulogenic in collagen gel. This is supported by the fact that either tamoxifen or the pure antiestrogen ICI-182,780 (ICI) abrogated these phenotypes. However, the invasion phenotype, an important marker of tumorigenesis is not modified when the cells are treated in presence of tamoxifen or ICI, suggesting that other pathways may be involved. Although we cannot rule out the possibility, that 4-OH-E(2) may interact with other receptors still not identified, with the data presently available the direct effect of 4-OH-E(2) support the concept that metabolic activation of estrogens mediated by various cytochrome P450 complexes, generating through this pathway reactive intermediates that elicit direct genotoxic effects leading to transformation. This assumption was confirmed when we found that all the transformation phenotypes induced by 4-OH-E(2) were not abrogated when this compound was used in presence of the pure antiestrogen ICI. The novelty of these observations lies in the role of ERbeta in transformation and that this pathway can successfully bypassed by the estrogen metabolite 4-OH-E(2). Genomic DNA was analyzed for the detection of micro-satellite DNA polymorphism using 64 markers covering chromosomes (chr) 3, 11, 13 and 17. We have detected loss of heterozygosity (LOH) in ch13q12.2-12.3 (D13S893) and in ch17q21.1 (D17S800) in E(2), 2-OH-E(2), 4-OH-E(2), E(2) + ICI, E(2) + tamoxifen and BP-treated cells. LOH in ch17q21.1-21.2 (D17S806) was also observed in E(2), 4-OH-E(2), E(2)+ICI, E(2)+tamoxifen and BP-treated cells. MCF-10F cells treated with P or P+E(2) did not show LOH in the any of the markers studied. LOH was strongly associated with the invasion phenotype. Altogether our data indicate that E(2) and its metabolites induce in HBEC LOH in loci of chromosomes 13 and 17, that has been reported in primary breast cancer, that the changes are similar to those induced by the chemical carcinogen (BP) and that the genomic changes were not abrogated by antiestrogens.

Detection of chromosomal aneusomy by fluorescence in situ hybridization for patients with nipple discharge

BACKGROUND

Breast carcinoma and precancer are believed to start in the lining of the milk duct or lobule. Ductography and fiberoptic ductoscopy (FDS) are used to identify abnormal intraductal lesions, although it is difficult to distinguish malignant from benign cases. Therefore, we studied the clinical usefulness of fluorescence in situ hybridization (FISH) analysis of a numerical aberration of chromosomes (aneusomy) using ductal lavage from patients with nipple discharge.

METHODS

We applied ductography and FDS to 90 women who had nipple discharge. Ductal lavages obtained from patients with positive ductography and/or FDS findings were subjected to cytology and FISH analysis using centromere probes for chromosomes 1, 11, and 17. Patients with samples that showed aneusomy in at least one of the three chromosomes were diagnosed as positive.

RESULTS

Histologic evaluation revealed 54 benign lesions and six malignancies. The sensitivity, specificity, and diagnostic accuracy were 33.3%, 88.9%, and 83.3%, respectively, for cytology and 100%, 100%, and 100%, respectively, for FISH.

CONCLUSION

The results demonstrated that FISH has a diagnostic accuracy comparable to cytology. This technique has 100% specificity is making a definitive diagnosis of malignancy in patients with indeterminate cytologic results, suggesting that FISH diagnosis can be a good adjunct to cytology.

A utility of ductography and fiberoptic ductoscopy for patients with nipple discharge

BACKGROUND

Breast carcinoma and precancer are thought to start in the lining of the milk duct or lobule. While ductography has been advocated as the main procedure in patients with nipple discharge, fiberoptic ductoscopy (FDS) is an emerging technique allowing direct visual access to the ductal system of the breast through nipple orifice exploration.

METHODS

We applied ductography and FDS to 65 women who had nipple discharge, and compared their utility.

RESULTS

Intraductal lesions occurred in the segmental duct and the first, second, third, fourth, fifth, and sixth branches in decreasing frequency with ductography and FDS screening. The detection rates of intraductal abnormal lesions by ductography and FDS and the their combination were 89.1 (37 patients), 97.4 (38 patients), and 97.5% (39 patients) respectively. Ductal washings performed during FDS were effective to obtain representative exfoliated ductal cells which could be evaluated (sensitivity 50%, specificity 94.3%, and diagnostic accuracy 89.7%). As a result, we diagnosed 35 cases of benign lesions and four cases of malignant lesions by cytological or/and histological examination.

CONCLUSION

Ductography and fiberoptic ductoscopy are useful procedure in guiding subsequent breast surgery in the treatment of nipple discharge.