Prognostic significance of atypical epithelial hyperplasia in nipple aspirates of breast fluid

Correlation of nipple aspiration and ductal lavage cytology with histopathologic findings for patients before scheduled breast biopsy examination

BACKGROUND

The use of ductal lavage to obtain cells from within the breast ducts has been described for patients at high risk for breast cancer. The purpose of this study was to correlate ductal lavage cytologic findings with the corresponding histology.

METHODS

Twenty-two patients were evaluated and 20 patients underwent ductal lavage followed by breast biopsy examination as a result of positive nipple aspiration fluid. Ductal lavage samples were classified by a cytopathologist as negative, mild atypia, marked atypia, or malignant. A different pathologist interpreted the histologic findings of the biopsy examination.

RESULTS

Adequate specimens for cellularity were obtained in 12 of 22 (53%) patients: 6 of the 12 (50%) had both benign cytology and histology, 2 (16.7%) had benign cytology with atypical ductal hyperplasia or atypical lobular hyperplasia on histology, 2 (16.7%) had marked atypia on cytology and benign histology, and 2 (16.7%) had malignant cytology and benign histology. The specificity of the procedure was 83.4%.

CONCLUSIONS

Ductal lavage yielding an adequate sample for analysis was successful in only 52% of patients. Of those, the cytologic-histologic correlation was discordant in 50%. The role of ductal lavage in accurately predicting lesions present on subsequent breast histologic evaluation of planned biopsy examinations requires further investigation.

Nipple aspirate fluid in relation to breast cancer

Samples of breast ductal fluid can be obtained by nipple aspiration. Such samples may contain a variety of exfoliated or shed cells and display a distinctive biochemical profile reflecting the microenvironment of the ductal-alveolar system of the breast. Study of nipple aspirates may, therefore, shed light on the biology of breast cancer. This review summarizes the more important aspects of published data and explores potential avenues for future study with particular regard to molecular-biological approaches.

Nipple aspirate fluid cytology in breast carcinoma

BACKGROUND

Nipple aspirate fluid (NAF) cytology is a simple noninvasive method to study cells exfoliated into the ductal system of the breast. In the current study, the significance of cytologic findings in NAF was determined by correlating them with histopathologic findings from corresponding breast tissue. Cytologic-histologic correlations of NAF were performed in only a few studies.

METHODS

Nipple aspirate fluid was collected by breast massaging and by using a breast aspiration device from 74 women with biopsy confirmed intraductal or invasive carcinoma with or without a history of preoperative neoadjuvant chemotherapy. Cytospin preparations were Pap stained. The number of epithelial cells was quantitated and foamy macrophages were semiquantitatively scored. Cytologic findings were categorized as insufficient for diagnosis (less than 10 epithelial cells), benign, mild atypia, marked atypia or suspicious, and malignant. Finally, they were correlated with tissue findings.

RESULTS

Nipple aspirate fluid was obtained from 74 women, including 24 who had received preoperative neoadjuvant chemotherapy. The median age of patients was 54 years. A mean volume of 57 microL NAF and a mean of 149 epithelial cells were obtained. Foamy macrophages were present in 51 (70%) of the specimens. There was a significant correlation between the presence of epithelial cells and foamy macrophages (P < 0.001). Patients treated with chemotherapy had fewer epithelial cells in their NAF compared with patients who were not treated with chemotherapy. Thirty specimens (41%) were inadequate for diagnosis, 34 were (46%) benign, 5 (7%) were mildly atypical, 1 (1%) was markedly atypical, and 4 (5%) were malignant. Of the five cases with mildly atypical cytology, three were intraductal papilloma, one was low-grade papillary intraductal carcinoma, and one was low-grade intracystic papillary carcinoma with invasion in the corresponding tissue specimen. The single case with markedly atypical NAF cytology had extensive ductal carcinoma in situ (DCIS). Of the four cases with malignant NAF cytology, two were extensive DCIS and two had invasive carcinoma with extensive DCIS in the breast specimen. Overall, 3 (27%) of 11 cases of DCIS were detected in NAF and only 2 (4%) of 52 invasive carcinomas including the only two cases with extensive DCIS were detected in NAF.

CONCLUSION

The probability of detecting malignant cells in NAF is dependent on the extent of DCIS and nipple involvement by DCIS. Nipple aspirate fluid is not a sensitive test for detecting invasive carcinoma of the breast. Atypical cytology in NAF is associated with papillary lesions in the underlying breast.

Presence of carotenoid, an anticarcinogenic marker, in nipple aspirates postlactation

Case-controlled studies have identified a protective effect of lactation against breast cancer; however, little is known about the nature of this protective mechanism. The purpose of this study was to examine postweaned, nipple aspirate fluid (NAF) from women, ages 18 to 45, for carotenoid, a known antioxidant and anticarcinogenic marker, and compare carotenoid availability in NAF with that reported in colostrum. Women who had lactated at least 6 months and weaned for at least 6 months were recruited into the study A prestudy and poststudy serum prolactin level was obtained. NAF was obtained through a nipple aspirator method. Total carotenoid ranged from 0.4 to 4.0 microg/mL, with a mean level of 1.9+/-1.2 (SD). Women who had weaned earlier (<12mo) had significantly more carotenoids than those who had lactated longer (>12mo) (P = 0.04). These levels were similar to those known to occur in colostrum. This research elucidates possible mechanisms of the protective effect of lactation on the microenvironment of the breast.

Cathepsin D in breast secretions from women with breast cancer

A proteinase accumulated in breast secretions from women with breast cancer has been characterised. Inhibition of the proteolytic activity of breast secretions by pepstatin A showed that the main enzyme involved was an aspartyl proteinase. Determination of its cleavage specificity by SDS-PAGE and amino acid sequence analysis revealed that it was identical to that of cathepsin D, an aspartyl proteinase suggested to be involved in breast cancer development. The identity between both proteins was further confirmed by immunological analysis with monoclonal antibodies against cathepsin D. Quantification of cathepsin D in nipple fluids from 41 women with benign or malignant breast diseases and from 19 control women without breast pathology revealed the presence of variable amounts of this proteinase. The average concentration of cathepsin D in breast secretions from cancer-bearing breasts was 7.2 +/- 2.2 fmol micrograms of protein, which was significantly higher than those of nipple fluids from control women (2.9 +/- 0.6 fmol micrograms-1) (P = 0.04) or from patients with benign breast diseases (2.1 +/- 0.3 fmol micrograms-1) (P = 0.004). Though the number of cancer patients studied was small (n = 21), no correlations were found with cytosolic concentrations of cathepsin D or oestrogen receptors, neither with other parameters such as tumour size, histological grade, axillary node involvement or menopausal status.

Factors affecting protein composition of breast secretions from nonlactating women

Breast secretions can be classified into two types according to their major protein components. Type I fluids contain Zn-alpha 2-glycoprotein, apolipoprotein D, and gross cystic disease fluid protein-15, while Type II fluids are characterized by the presence of lactoferrin, lysozyme, and alpha-lactalbumin. In this study, the polypeptide composition of breast secretions from 719 nonlactating women was evaluated by using polyacrylamide gel electrophoresis. The required amount for the analysis (1 microliter) was obtained from 50% of control women and from 75% of women with mammary disease. There were more secretors in premenopausal than in postmenopausal women, as well as in parous than in nulliparous women. Evaluation of factors affecting protein composition of breast secretions revealed that Type II fluids were found in the majority of women who had given birth in the last four years and in a high proportion of oral contraceptive users. After excluding both of these groups, Type II fluids were detected in 47% of patients with breast cancer, but only in 8% of control women and in 16% of women with benign breast diseases. Taken together, these results suggest that protein analysis of breast secretions could be an useful tool for the study of breast pathologies.

Cerumen phenotype and proliferative epithelium in breast fluids of U.S.-born vs. immigrant Asian women: a possible genetic-environmental interaction

To determine whether a genetic-environmental interaction exists between the breast, a modified apocrine gland, its secretions, and the genetic polymorphic phenotypes of wet and dry cerumen, we examined nipple aspirate fluid (NAF) for proliferative disease in 172 U.S.-born and immigrant Chinese and Japanese women. Cytologic evidence of proliferative epithelial cells (benign hyperplasia and/or atypical hyperplasia) was found in the NAF of 36 women (20.9%). A significantly higher incidence of proliferative epithelial cells was present in the NAF of U.S.-born than in immigrant Asian women (28.6% vs. 16.5%) (p = 0.05). A higher proportion of U.S.-born Asian women with wet cerumen than women with dry cerumen had proliferative epithelial cells in NAF: 39.3% vs. 20.0% (p = 0.08). No significant difference in NAF proliferative cells was found between immigrant women with wet and dry cerumen: 15.8% vs. 17.3%; p = 0.50. A strong association of proliferative epithelial cells and cerumen phenotype was found in parous U.S.-born women (wet = 47.6% vs. dry = 16.0%; p = 0.002). No significant association with wet and dry cerumen phenotype was found in parous immigrant women (wet = 12.2% vs. dry = 20%). These findings support the hypothesis that an apocrine genetic polymorphic trait differentially influences susceptibility of the breast to proliferative disease in Asian women born in environments presumed to be of high risk for breast cancer compared to women from low risk environments.

Bloody nipple discharge during pregnancy: a rationale for conservative treatment

Five cases of bloody nipple discharge during pregnancy without associated breast masses were seen over the past 3 years by the author. Because of the reported association of breast cancer with bloody nipple discharge, close follow-up of these women at monthly intervals during pregnancy and trimonthly during the postpartum period was carried out. In all instances, the discharge appeared late during the second trimester or during the third trimester of pregnancy. It was unilateral and spontaneous and arose from multiple ducts, and it was associated with an increase in breast size and always with the larger breast of the two. The discharge cytologic study done on all cases was negative for neoplastic cells and the discharges resolved spontaneously within 2 months of onset. Postpartum follow-up ranging from 6 months to 3 years has revealed no evidence of neoplastic changes thus far. Mammograms ordered before these patients were referred were not helpful due to the increase in density of the breast tissue secondary to the pregnancy. Because a few cases of breast cancer during pregnancy have presented solely with a bloody nipple discharge, I recommend extremely close follow-up of these women and no surgical intervention unless a mass is discovered or the nipple discharge cytology is either suspicious or positive at the initial visit or during follow-up.

Factors associated with obtaining nipple aspirate fluid: analysis of 1428 women and literature review

Studies of cytologic and biochemical constituents of nipple aspirates of breast fluid have contributed to understanding the natural history of benign and malignant breast disease. We conducted multivariate analyses using 1428 women from a recent case-control study of breast disease to determine which factors were independently associated with the ability to obtain breast fluid from nonlactating women. We then compared results from these analyses to the results from five previous studies that also used the aspiration technique of Sartorius. Four factors were consistently associated across studies with increased ability to obtain breast fluid: 1) age up to 35 to 50 years; 2) earlier age at menarche; 3) non-Asian compared to Asian ethnicity; and 4) history of lactation. Exogenous estrogen use, endogenous estrogen concentrations, phase of menstrual cycle, family history of breast cancer, type of menopause, and less than full-term pregnancy consistently did not influence ability to obtain fluid. New findings from this study shed light on some apparently contradictory findings from the previous studies. In particular, this study showed that the effects of age on ability to obtain fluid appeared to be independent of the effects of menopause. Furthermore, discrepancies in previous findings on the effects of parity on ability to obtain fluid may be explained by our finding that the increased ability to obtain fluid from parous compared to nulliparous women applied only to parous women who had breastfed.