Failure of high risk women to produce nipple aspirate fluid does not exclude detection of cytologic atypia in random periareolar fine needle aspiration specimens

Nipple Aspirate Fluid at a Glance

Simple Summary

Nipple aspirate fluid (NAF) is a promising source of markers for detection of breast cancer. NAF can be acquired via the nipple by aspiration using a suction device, which is well tolerated by women. Future possible applications of biomarkers for breast cancer derived from NAF could be (1) as a detection tool to identify the initiation of the cancer development process, (2) as an additional tool next to imaging (mammography and breast magnetic resonance imaging) or (3) as a replacement tool for when imaging is not advisable for women, such as during pregnancy and breastfeeding. With this paper, we present a narrative review and perspectives of NAF research at a glance.

Abstract

Nipple aspirate fluid (NAF) is an intraductal mammary fluid that, because of its close proximity to and origin from the tissue from which breast cancer originates, is a promising source of biomarkers for early breast cancer detection. NAF can be non-invasively acquired via the nipple by aspiration using a suction device; using oxytocin nasal spray helps increase yield and tolerability. The aspiration procedure is generally experienced as more tolerable than the currently used breast imaging techniques mammography and breast magnetic resonance imaging. Future applications of NAF-derived biomarkers include their use as a tool in the detection of breast carcinogenesis at its earliest stage (before a tumor mass can be seen by imaging), or as a supporting diagnostic tool for imaging, such as when imaging is less reliable (to rule out false positives from imaging) or when imaging is not advisable (such as during pregnancy and breastfeeding). Ongoing clinical studies using NAF samples will likely shed light on NAF’s content and clinical potential. Here, we present a narrative review and perspectives of NAF research at a glance.

Breast cancer risk assessment, prevention, and the future

Today breast cancer remains a major public health problem, although reducing its risk is now an achievable medical objective. Risk-assessment models may be used in estimating a woman's risk for developing breast cancer and to direct suitable candidates for preventive therapy. Researchers are attempting to enhance individualized risk assessment through incorporation of phenotypic biomarkers. Individual selective estrogen receptor modulators have been approved for breast cancer risk reduction, and other drug categories are being studied. It is critical that obstetrician-gynecologists be familiar with the evolving science of the risk assessment of breast cancer as well as interventional and surveillance strategies.

Comparison of Random Periareolar Fine Needle Aspirate versus Ductal Lavage for Risk Assessment and Prevention of Breast Cancer

Random periareolar fine needle aspiration (RPFNA) and ductal lavage (DL) are research techniques developed to (1) assess short-term breast cancer risk in asymptomatic women who are at increased risk for breast cancer and (2) track cytological response to risk reduction strategies. RPFNA and DL provide minimally invasive methods to repeatedly sample epithelial cells and research tools to investigate the biological origins of breast cancer in high-risk women. This review gives an overview of the strengths and limitations of both RPFNA and DL for risk assessment and breast cancer prevention in asymptomatic high-risk women.

Tolerability of breast ductal lavage in women from families at high genetic risk of breast cancer

BACKGROUND

Ductal lavage (DL) has been proposed as a minimally-invasive, well-tolerated tool for obtaining breast epithelial cells for cytological evaluation of breast cancer risk. We report DL tolerability in BRCA1/2 mutation-positive and -negative women from an IRB-approved research study.

METHODS

165 BRCA1/2 mutation-positive, 26 mutation-negative and 3 mutation unknown women underwent mammography, breast MRI and DL. Psychological well-being and perceptions of pain were obtained before and after DL, and compared with pain experienced during other screening procedures.

RESULTS

The average anticipated and experienced discomfort rating for DL, 47 and 48 (0-100), were significantly higher (p < 0.01) than the anticipated and experienced discomfort of mammogram (38 and 34), MRI (36 and 25) or nipple aspiration (42 and 27). Women with greater pre-existing emotional distress experienced more DL-related discomfort than they anticipated. Women reporting DL-related pain as worse than expected were nearly three times more likely to refuse subsequent DL than those reporting it as the same or better than expected. Twenty-five percent of participants refused repeat DL at first annual follow-up.

CONCLUSION

DL was anticipated to be and experienced as more uncomfortable than other procedures used in breast cancer screening. Higher underlying psychological distress was associated with decreased DL tolerability.

Ductal lavage in women from BRCA1/2 families: is there a future for ductal lavage in women at increased genetic risk of breast cancer?

PURPOSE

Ductal lavage has been used for risk stratification and biomarker development and to identify intermediate endpoints for risk-reducing intervention trials. Little is known about patient characteristics associated with obtaining nipple aspirate fluid (NAF) and adequate cell counts (> or =10 cells) in ductal lavage specimens from BRCA mutation carriers.

METHODS

We evaluated patient characteristics associated with obtaining NAF and adequate cell counts in ductal lavage specimens from the largest cohort of women from BRCA families yet studied (BRCA1/2 = 146, mutation-negative = 23, untested = 2). Fisher's exact test was used to evaluate categorical variables; Wilcoxon nonparametric test was used to evaluate continuous variables associated with NAF or ductal lavage cell count adequacy. Logistic regression was used to identify independent correlates of NAF and ductal lavage cell count adequacy.

RESULTS

From 171 women, 45 (26%) women had NAF and 70 (41%) women had ductal lavage samples with > or =10 cells. Postmenopausal women with intact ovaries compared with premenopausal women [odds ratio (OR), 4.8; P = 0.03] and women without a prior breast cancer history (OR, 5.2; P = 0.04) had an increased likelihood of yielding NAF. Having breast-fed (OR, 3.4; P = 0.001), the presence of NAF before ductal lavage (OR, 3.2; P = 0.003), and being premenopausal (OR, 3.0; P = 0.003) increased the likelihood of ductal lavage cell count adequacy. In known BRCA1/2 mutation carriers, only breast-feeding (OR, 2.5; P = 0.01) and the presence of NAF (OR, 3.0; P = 0.01) were independent correlates of ductal lavage cell count adequacy.

CONCLUSIONS

Ductal lavage is unlikely to be useful in breast cancer screening among BRCA1/2 mutation carriers because the procedure fails to yield adequate specimens sufficient for reliable cytologic diagnosis or to support translational research activities.

Facile whole mitochondrial genome resequencing from nipple aspirate fluid using MitoChip v2.0

Background

Mutations in the mitochondrial genome (mtgenome) have been associated with many disorders, including breast cancer. Nipple aspirate fluid (NAF) from symptomatic women could potentially serve as a minimally invasive sample for breast cancer screening by detecting somatic mutations in this biofluid. This study is aimed at 1) demonstrating the feasibility of NAF recovery from symptomatic women, 2) examining the feasibility of sequencing the entire mitochondrial genome from NAF samples, 3) cross validation of the Human mitochondrial resequencing array 2.0 (MCv2), and 4) assessing the somatic mtDNA mutation rate in benign breast diseases as a potential tool for monitoring early somatic mutations associated with breast cancer.

Methods

NAF and blood were obtained from women with symptomatic benign breast conditions, and we successfully assessed the mutation load in the entire mitochondrial genome of 19 of these women. DNA extracts from NAF were sequenced using the mitochondrial resequencing array MCv2 and by capillary electrophoresis (CE) methods as a quality comparison. Sequencing was performed independently at two institutions and the results compared. The germline mtDNA sequence determined using DNA isolated from the patient's blood (control) was compared to the mutations present in cellular mtDNA recovered from patient's NAF.

Results

From the cohort of 28 women recruited for this study, NAF was successfully recovered from 23 participants (82%). Twenty two (96%) of the women produced fluids from both breasts. Twenty NAF samples and corresponding blood were chosen for this study. Except for one NAF sample, the whole mtgenome was successfully amplified using a single primer pair, or three pairs of overlapping primers. Comparison of MCv2 data from the two institutions demonstrates 99.200% concordance. Moreover, MCv2 data was 99.999% identical to CE sequencing, indicating that MCv2 is a reliable method to rapidly sequence the entire mtgenome. Four NAF samples contained somatic mutations.

Conclusion

We have demonstrated that NAF is a suitable material for mtDNA sequence analysis using the rapid and reliable MCv2. Somatic mtDNA mutations present in NAF of women with benign breast diseases could potentially be used as risk factors for progression to breast cancer, but this will require a much larger study with clinical follow up.

Comparison of Ductal Lavage and Random Periareolar Fine Needle Aspiration as Tissue Acquisition Methods in Early Breast Cancer Prevention Trials

PURPOSE

Short-term phase I and phase II breast cancer prevention trials require tissue acquisition at baseline and after intervention to evaluate modulation of potential biomarkers. Currently used tissue acquisition methods include ductal lavage (DL), random periareolar fine needle aspiration (RPFNA), and core needle biopsy. The optimum method to retrieve adequate samples and the most accepted method by study participants is not known.

EXPERIMENTAL DESIGN

We compared RPFNA and DL as breast tissue acquisition methods for short-term breast cancer prevention trials by evaluating sample adequacy and tolerability in subjects who participated in two prospective phase II breast cancer prevention trials. Eighty-six women at increased risk for breast cancer were included in this study and underwent baseline DL and RPFNA. High risk was defined as having a 5-year Gail score of >1.67% or a history of atypical hyperplasia (AH), lobular carcinoma, or breast cancer.

RESULTS

Median age was 54.5 years (range, 39-75 years); 75% of the women were postmenopausal. About 51% of the women yielded nipple aspiration fluid, and breast fluid samples via DL were retrieved in 73% of these subjects. Of these samples, 71% were adequate samples (greater than 10 epithelial cells). However, when the entire cohort was considered, only 31% of the subjects had adequate samples. RPFNA was also attempted in all subjects, and sample retrieval rate was 100%. Out of these, 96% of the subjects had adequate samples. In DL samples, AH rate was 3.7% was and hyperplasia (H) rate was 11.1%. In RPFNA samples, AH rate was 12.9%, and H rate was 24.7%. Cytology findings in RPFNA samples correlated with age, menopausal status, and breast cancer risk category (previous history of lobular carcinoma in situ). Both procedures were well tolerated, and no complications occurred among participants.

CONCLUSIONS

Considering that the main end point for short-term prevention trials is the modulation of biomarkers, it is important to optimize adequate sample acquisition; therefore, RPFNA is a more practical option for future phase I and II breast cancer prevention trials compared with DL.

Patient variables that predict atypical cytology by nipple duct lavage

BACKGROUND

Nipple duct lavage (NDL) may be useful for breast cancer risk stratification. Published guidelines recommend that women with a 5-year Gail risk >/=1.7% should consider undergoing lavage for any fluid-yielding ducts, but it is not known whether increased breast cancer risk or nipple fluid production predict lavage atypia.

METHODS

One hundred fifty women unselected for breast cancer risk underwent NDL with cannulation of all nipple aspirate fluid (NAF)-producing ducts and at least 1 dry duct. This resulted in 516 lavage samples. The rate of cytologic atypia was compared for NAF-positive ducts and NAF-negative ducts and for women with 5-year Gail risks >/=1.7% and <1.7%. Ducts from breasts with cancer (N = 113) were excluded from the analysis.

RESULTS

The cytologic atypia rate was similar for the 240 NAF-producing ducts (19%) and the 163 dry ducts (15%; P = .36). No significant differences were observed when atypia was categorized as mild (13% vs 10%; P = .63) or marked (6% vs 4%; P = .53). Among the 83 patients who were unaffected by breast cancer, atypia was diagnosed in 15 of 44 patients (34%) with a 5-year Gail risk <1.7% and in 11 of 39 patients (28%) with a 5-year Gail risk >/=1.7% (P = .74).

CONCLUSIONS

Neither NAF production nor 5-year Gail risk predicted lavage atypia. Limiting NDL to fluid-producing ducts in women with a 5-year Gail risk >/=1.7% significantly reduced the sensitivity of the test for population screening.

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

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.

A descriptive study of variables associated with obtaining nipple aspirate fluid in a cohort of non-lactating women

BACKGROUND

The search for biologic endpoints and biomarkers in the study of breast cancer risk assessment and risk reduction strategies has led to an interest in obtaining cytologic information and other biomarkers from nipple aspirate fluid (NAF).

METHODS

This descriptive study examined factors associated with an increased ability to obtain NAF in a cohort of 3043 women between the ages of 15 and 89 years of age. The majority of women were between the ages of 30-49 (N = 1529/50.2%). Variables examined in relation to obtaining fluid include: age, marital status, age at menarche, menopausal status, a history of pregnancy, a history of breast-feeding, estrogen use, oral contraceptive use, endocrine disorders and tranquilizer use.

RESULTS

On average, women from whom breast fluid was obtained were younger than women from whom breast fluid was attempted but not obtained (mean = 41.9 years versus 46.5 years, p < 0.0001). In unadjusted and age-adjusted comparisons, being married, a history of pregnancy, younger age at menarche (12 years of age or younger), tranquilizer use, oral contraceptive pill (OCP) use and endocrine problems were associated with an increased ability to obtain breast fluid. Post-menopausal status and exogenous estrogen use were associated with a decreased ability to obtain breast fluid. After age-adjustment, oral contraceptive use was no longer significantly associated with an increased ability to obtain fluid and post-menopausal status was no longer associated with a decreased ability to obtain breast fluid. After multivariate adjustment, age, being married, a history of pregnancy, tranquilizer use and a history of endocrine problems remained positively associated with the ability to obtain breast fluid. In addition, menopausal women who took estrogen were less likely to yield fluid than premenopausal women.

CONCLUSION

Four variables (being married, history of pregnancy, tranquilizer use and endocrine disorders) remained positively associated with the ability to obtain NAF in all analyses. A younger age was consistently associated with a greater ability to obtain NAF in this and other studies.

Ductoscopy and intraductal vacuum assisted biopsy in women with pathologic nipple discharge

BACKGROUND

Fiberoptic ductoscopy is increasingly used to evaluate pathologic nipple discharge. A major limitation of this technique is the inability to obtain tissue samples from suspicious intraductal lesions. We present a novel technique for ductoscopic biopsy of intraluminal tumors.

METHODS

From 2002 to 2005 ductoscopy was performed in 38 women with nipple discharge using a rigid gradient index microendoscope (diameter 0.7 mm) and a special needle for intraductal vacuum assisted biopsy. Results of preoperative biopsy were correlated with the histology of the resection specimen

RESULTS

Cannulation of the discharging duct was successful in 37 of 38 patients (97%). Intraductal lesions were diagnosed in 29 women (78%). The sensitivity of ductoscopy and galactography in the detection of intraductal lesion was comparable (96% vs. 89%). Ductoscopic biopsy of intraductal lesions was technically successful in all but one case. Generally, the quality of the biopsy samples was good. Diagnostic biopsy samples were obtained in 26 of 28 patients (93%). Two samples contained necrosis and were considered to be non-representative. Histological analysis of the biopsy specimens showed 22 papilloma, 2 in situ carcinoma and 2 invasive carcinoma. Histology of the resection specimens confirmed the diagnosis in all cases, but there was one case with additional carcinoma lobulare in situ.

CONCLUSIONS

Ductoscopic vacuum assisted biopsy is a new technique for tissue sampling of intraductal breast lesions. This method may improve preoperative evaluation of pathologic nipple discharge in selected patients, but it should not be considered as a method for screening of early breast cancer.

Ductal lavage of fluid-yielding and non-fluid-yielding ducts in BRCA1 and BRCA2 mutation carriers and other women at high inherited breast cancer risk

OBJECTIVE

Nipple fluid production and atypical breast duct cells in women at high risk of breast cancer have been associated with further increased risk. Most publications on ductal lavage for cell collection report cannulating fluid-yielding ducts only. We report lavage of fluid-yielding and non-fluid-yielding ducts in women at high inherited breast cancer risk.

METHODS

A pilot breast cancer screening study including ductal lavage was conducted in 75 women at high inherited risk, 56 (74.7%) of whom had BRCA1/2 mutations. Ductal lavage was attempted in any duct identifiable with a catheter.

RESULTS

Ducts were successfully catheterized in 60 of 75 patients (80%). Successfully catheterized patients were younger (median age 41 versus 53 years, P = 0.0003) and more often premenopausal (51.7% versus 20%, P = 0.041). Thirty-one successfully catheterized patients [51.6%, 95% confidence interval (39.4-63.9%)] had non-fluid-yielding ducts only. Seventeen patients [28.3% (18.5-40.9%)] had atypical cells. Twelve of seventeen [70.6% (46.8-87.2%)] samples with atypia were from non-fluid-yielding ducts. Patients with non-fluid-yielding ducts (versus fluid-yielding ducts) were more likely to have had prior cancer (48.4% versus 17.2%, P = 0.014) or chemotherapy (45.2% versus 17.2%, P = 0.027); this was also true in patients with atypia from non-fluid-yielding ducts.

CONCLUSION

Successfully lavaged women were younger and more often premenopausal. Atypical cells can be found in non-fluid-yielding ducts in patients at high inherited breast cancer risk. Non-fluid-yielding ducts, and atypia from non-fluid-yielding ducts, are more common in patients with prior cancer and chemotherapy. Larger studies are needed to identify risk factors and prognostic significance associated with atypia and non-fluid-yielding ducts in high-risk populations, and define their role as biomarkers.

Comparison of cytomorphology in specimens obtained by random periareolar fine needle aspiration and ductal lavage from women at high risk for development of breast cancer

Ductal lavage (DL) and random periareolar fine needle aspiration (RPFNA) are both being used to harvest epithelial cells for risk assessment as well as response evaluation in chemoprevention trials. The magnitude of increase in relative risk has been defined in a prospective study for RPFNA but not for DL atypia. We attempted both procedures in 26 women at high risk for development of breast cancer. Median age was 43 (range 32-57); 15 women were premenopausal, with 6 of the postmenopausal women on HRT. Collection of nipple aspirate fluid (NAF) was attempted and, if successful, was followed by DL; RPFNA was then performed on all women. Both procedures were attempted the same day (follicular phase of menstrual cycle if premenopausal) in 24 subjects and within three months for two subjects. Twenty-three subjects produced NAF, 17 of the 23 (74%) had a successful duct cannulation as part of the DL procedure, with 16 yielding sufficient (10) ductal cells for morphologic assessment. Twenty-five of 26 (96%) subjects had a successful RPFNA procedure with adequate cellularity for morphology. There was concordance between DL and RPFNA specimens for traditional cytologic category assessment in 10/16 (63%), Masood index score in 13/16 (82%), and Consensus Panel assessment in 12/16 (75%) of specimens. We conclude that same day DL and RPFNA is feasible, with 62% and 96% of high-risk women having a successful procedure with evaluable cytomorphology. RPFNA was more likely to yield an evaluable specimen, but if a cellular DL specimen was obtained, morphology was generally similar.

Patterns of reduced nipple aspirate fluid production and ductal lavage cellularity in women at high risk for breast cancer

INTRODUCTION

Nipple aspiration is a noninvasive technique for obtaining breast fluids from the duct openings of the nipple for the evaluation of abnormalities associated with breast cancer. Nipple aspirate fluid (NAF) can be elicited from 48 to 94% of healthy women, and its production has been linked to an increased relative risk for breast cancer development. NAF production has been used in studies to guide the selection of ducts for ductal lavage, a procedure in which ducts are cannulated and flushed with saline to collect cells. In a previous multicenter trial to evaluate intraductal approaches in women at high-risk for breast cancer, NAF production was observed in 84% of the subjects. However, we observed a significantly lower proportion of fluid-yielding subjects in a similar series of high-risk women. The purpose of the present study was to identify variables associated with this reduction.

METHOD

Nipple aspiration was performed on 33 high-risk women (defined as having a 5-year Gail model index of more than 1.7, a personal or family history of breast cancer, and/or a BRCA1 or BRCA2 germline mutation) to identify ductal orifices for lavage procedures. Lavage was performed on all fluid-yielding ducts and on nine non-fluid-yielding ducts.

RESULTS

Fluid-yielding ducts were identified in 12 of 33 (36%) of the subjects in the present series, compared with 16 of 19 (84%) of the subjects undergoing identical procedures at our facility during a multicenter trial (P = 0.001). Reduced NAF yields were associated with postmenopausal status (P = 0.02), BRCA germline mutations (P = 0.004), and risk reduction therapies, including bilateral salpingo-oophorectomy (BSO) and/or selective estrogen receptor modulators (SERMs; P = 0.009). All nine (100%) of the ductal lavage specimens collected from non-fluidyielding ducts were acellular, in comparison with 3 of 13 specimens from fluid-yielding ducts (P < .001).

CONCLUSION

Analysis of high-risk women in the present series revealed patterns of reduced NAF production and ductal lavage cellularity compared with a previous multicenter trial. The present series included more BRCA-positive women, many of whom had undergone BSO and/or were using SERMs. Our data suggest that endocrine mechanisms associated with these risk-reducing therapies may be related to patterns of diminished breast fluid production.

The Fourth International Symposium on the Intraductal Approach to Breast Cancer, Santa Barbara, California, 10-13 March 2005

Intraductal approaches encompass procedures and technologies that are designed to access and interrogate the ductal–alveolar systems of the human breast, and include nipple aspiration, ductal lavage, random periareolar fine needle aspiration, and ductoscopy. These approaches are being used to collect and analyze fluids and cells to develop methods for breast cancer detection and risk assessment; to introduce imaging technologies to explore the mammary tree for abnormalities; to administer therapeutic and/or preventive agents directly to the breast tissue; and to explore the biology of the normal mammary gland. The latest research findings in these areas, presented at The 4th International Symposium on the Intraductal Approach to Breast Cancer in 2005, are summarized in this report.