The clinical applications of mammary ductoscopy

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.

Risk factors of breast intraductal lesions in patients without pathological nipple discharge

The majority of breast cancer arises from the ductal epithelium. It is crucial in the diagnosis and treatment of breast cancer by detecting intraductal lesions at an early stage. The typical clinical characteristic of intraductal lesions is pathological nipple discharge (PND), although many patients with intraductal lesions do not exhibit PND. It is a serious challenge for clinicians to detect patients with intraductal lesions without PND at an early stage. The aim of the present study was to investigate the risk factors associated with intraductal lesions in patients without PND. This retrospective database review, conducted between April 2016 and April 2017, included 370 lesions from 255 patients with intraductal lesions (intraductal papilloma, atypical intraductal hyperplasia, intraductal carcinoma in situ) and non-intraductal lesions (fibroadenoma, adenosis, cysts, lobular carcinoma in situ), diagnosed through surgical pathology. The patients were divided into two groups based on pathological diagnosis and clinical parameters were evaluated using univariate and multivariate analyses. Univariate analysis revealed that 9 of 14 factors were statistically significant. Five factors were identified to be associated risk factors in patients without PND through the multivariate logistic regression analysis: Age between 35 and 49 years and age ≥50 years [odds ratio (OR)=4.749, 95% confidence interval (CI)=2.371-9.513, P<0.001; OR=2.587, 95% CI=2.587-14.891, P<0.001; respectively], non-menstrual breast pain (OR=1.922, 95% CI=1.037-3.564, P=0.038), breast duct dilatation as seen using ultrasonography (OR=9.455, 95% CI=3.194-27.987, P<0.001), lesion distance from nipple ≤2 cm (OR=2.747, 95% CI=1.668-4.526, P<0.001) and lesion size ≤1 cm (OR=1.903, 95% CI=1.155-3.136, P=0.012). In conclusion, for patients without PND but with risk factors, such as the patient being >35 years, with non-menstrual breast pain, breast duct ectasia, lesion distance from nipple ≤2 cm and lesion size ≤1 cm as seen using ultrasonography, clinicians should be highly concerned about the possibility of intraductal lesions, in order to prevent misdiagnosis and reduce the misdiagnosis rate.

Duct Excision is Still Necessary to Rule out Breast Cancer in Patients Presenting with Spontaneous Bloodstained Nipple Discharge

Introduction. Spontaneous nipple discharge is the third most common reason for presentation to a symptomatic breast clinic. Benign and malignant causes of spontaneous nipple discharge continue to be difficult to distinguish. We analyse our experience of duct excisions for spontaneous nipple discharge to try to identify features that raise suspicion of breast cancer and to identify features indicative of benign disease that would be suitable for nonoperative management. Methods. Details of one hundred and ninety-four patients who underwent duct excision for spontaneous nipple discharge between 1995 and 2005 were analysed. Results. Malignant disease was identified in 11 (5.7%) patients, 4 invasive and 7 insitu, which was 10.2% of those presenting with bloodstained discharge. All patients with malignant disease had bloodstained discharge. Discharge due to malignant disease was more likely to be bloodstained than that due to benign causes (Fisher's exact test, 2-tailed P value = 0.00134). Conclusion. Our findings do not support a policy of conservative management of spontaneous bloodstained nipple discharge. Cases of demonstrable spontaneous bloodstained nipple discharge should undergo duct excision to prevent malignant lesions being missed.

Breast duct endoscopy: ductoscopy from a diagnostic to an interventional procedure and its future perspective

OBJECTIVE

Breast duct endoscopy is increasingly used for evaluation of intraductal disease. We present a new rigid instrument for ductoscopy that allows intraductal biopsy and the removal of small lesions.

METHODS

Overall, 102 women with breast cancer or pathologic nipple discharge were included in the analysis. All ductoscopies were performed with a rigid gradient index micro-endoscope (phi 0.7 mm) in combination with a special device for intraductal vacuum assisted biopsy. Ductoscopy, ductal lavage and intraductal biopsy were correlated with ductal cytology and histopathology of the resection specimen.

RESULTS

Gradient index ductoscopy provided high resolution images of the breast ducts and identified additional intraductal lesions in 45% of the patients with breast cancer. The accuracy of ductal lavage, ductoscopy and mammography in the detection of an extensive intraductal component was 14%, 65% and 50%, respectively. Intraductal vacuum assisted biopsy yielded diagnostic material in 92% of 38 patients with nipple discharge and papillomatous lesions. Histology of the resection specimen confirmed the diagnosis in all cases including 2 in situ carcinoma and 2 invasive ductal carcinoma.

CONCLUSIONS

Ductoscopy is a useful supplement for the standard radiological workup of breast cancer especially in patients with extensive intraductal carcinoma. Ductoscopic vacuum assisted biopsy is an effective technique for intraductal tissue sampling and allows ablation of small lesions. This technique provides new perspectives for interventional therapy of intraductal tumours.

Nipple aspirate fluid and ductoscopy to detect breast cancer

We prospectively performed cytologic assessment and image analysis (IA) on matched nipple aspirate fluid (NAF) and mammary ductoscopy (MD) specimens to determine (1) the accuracy of these methods in cancer detection and (2) whether the two collection methods provide complementary information.NAF and MD specimens were collected from 84 breasts from 75 women (nine bilateral samples) who underwent breast surgery. Cytologic evaluation was performed on all samples. IA was performed on slides with sufficient epithelial cells.Cytologic evaluation proved more accurate in patients without pathologic spontaneous nipple discharge (PND) than those with PND, mainly because of the potential false positive diagnosis in the latter. While the sensitivity of NAF and MD cytology was low (10% and 14%, respectively), both were 100% specific in cancer detection in the non-PND cohort. Combining NAF and MD cytology information improved sensitivity (24%) without sacrificing specificity. Similar to cytology, IA was more accurate in patients without PND having high specificity (100% for aneuploid IA), but relatively low sensitivity (36%). Combining NAF and MD cytology with aneuploid IA improved the sensitivity (45%) while maintaining high specificity (100%). The best predictive model was positive NAF cytology and/or MD cytology combined with IA aneuploidy, which resulted in 55% sensitivity and 100% specificity in breast cancer detection.Cytologic evaluation and IA of NAF and MD specimens are complementary. The presence of atypical cells arising from an intraductal papilloma in ductoscopic specimens is a potential source of false positive diagnosis in patients with nipple discharge.

Mammary ductoscopy and ductal washings for the evaluation of patients with pathologic nipple discharge

The majority of breast diseases result from lesions of the ductal epithelium. Mammary ductoscopy allows for visualization of intraductal abnormalities, and ductoscopic lavage provides thousands of cells for analysis. We reviewed our experience of 89 cases of patients with pathologic nipple discharge (PND) undergoing ductoscopy-directed duct excision and collection of ductal washings. Patients undergoing ductoscopy-directed duct excision with ductal washings had an 88% abnormal pathology rate. Most abnormalities were benign (71% papillomas), but the atypia rate for this group was 62%. The combination of visualization and pathologic analysis of washings provided the highest predictive value for the diagnosis of papilloma. Cellular yields for this technique were excellent with most specimens yielding >5,000 epithelial cells per high powered field and with evaluable ductal cells in 82% of specimens. Mammary ductoscopy offers the advantage of a high lesion localization rates with intraoperative guidance. The most accurate tool was the combination of ductal washings and ductoscopic visualization, but preoperative use of these techniques is not helpful in most cases. Greater than 90% of patients with PND are found to have a lesion on pathologic examination when using this technique for directed duct excision. Of interest, ductal washings obtained from symptomatic patients with benign diseases are often atypical.

Minimally invasive technology in the management of breast disease

Minimally invasive surgery is gaining popularity around the world because it achieves the same or even superior results when compared to standard surgery but with less morbidity. Minimally invasive breast surgery is a broad concept encompassing new developments in the field of breast surgery that work on this minimally invasive principle. In this regard, breast-conserving surgery and sentinel lymph node biopsy are good illustrations of this concept. There are three major areas of progress in the minimally invasive management of breast disease. First, percutaneous excisional devices are now available that can replace the surgical excision of breast mass lesions. Second, various ablative treatments are capable of destroying breast cancers in situ instead of surgical excision. Third, mammary ductoscopy provides a new approach to the investigation of mammary duct pathology. Clinical experience and potential applications of these new technologies are reviewed.

Breast ductal secretions: clinical features, potential uses, and possible applications

BACKGROUND

Nipple discharge accounts for approximately 5% of visits to a breast specialist surgical practice and may be encountered as the chief complaint by many other types of physicians. The vast majority of breast cancers originate in the ductal system, which prompted interest in the evaluation of the intraductal approach to breast cancer. Ductoscopy, nipple aspiration, and ductal lavage have emerged as innovative fields of study that may have clinical applications.

METHODS

We performed a literature search of published manuscripts using the keywords nipple discharge, breast ductal secretions, and intraductal approach. We also report our single-institution experience in managing nipple discharge.

RESULTS

We present our institutional algorithm for the management of nipple discharge. The possible etiologies of nipple discharge and the appropriate workup are reviewed. Three evolving minimally invasive techniques for the evaluation of high-risk patients include ductoscopy, nipple aspiration, and ductal lavage. Nipple aspiration and ductal lavage fluid may be assayed for cytology, genomic, gene expression, and proteomic studies. Several different translational approaches are being undertaken to investigate the local microenvironment associated with the development and progression of breast carcinoma.

CONCLUSIONS

Nipple aspiration fluid and ductal lavage offer the opportunity to study the local microenvironment of the ductal system, which is where most breast cancers originate. These powerful approaches to biomarker analysis could be applied to the prevention and treatment of breast cancer.

Gradient index ductoscopy and intraductal biopsy of intraductal breast lesions

OBJECTIVE

Breast duct endoscopy is increasingly used for evaluation of intraductal disease. We have investigated a new rigid instrument for ductoscopy and intraductal biopsy of pathologic lesions.

METHODS

From 2002 to 2006, ductoscopy was performed in 111 women with breast cancer or pathologic nipple discharge. A rigid gradient index microendoscope (diameter .7 mm) was used for all examinations in combination with a specially developed needle for intraductal vacuum-assisted biopsy. Ductoscopy and intraductal biopsy were correlated with ductal cytology and histopathology of the resection specimen.

RESULTS

Ductoscopy identified intraductal lesions in 41% of the patients with breast cancer presenting as red patches, microcalcifications, or ductal obstruction. Compared with patients with a normal ductoscopy, patients with pathologic ductoscopy had a significantly higher risk of extensive intraductal carcinoma (71% versus 16%, P < .05). Ductal cytology showed only a few cases with severe cytologic atypia or malignant cells in cases with ductoscopic abnormalities. Intraductal vacuum-assisted biopsy yielded diagnostic material in 89% of 36 patients with nipple discharge and papillomatous lesions. Histology of the resection specimen confirmed the diagnosis in all cases (26 papillomas, 2 in situ carcinomas, and 2 invasive ductal carcinomas). In contrast, ductal cytology showed only moderate correlation with histopathology.

CONCLUSIONS

Ductoscopy is a useful supplement for the standard radiological workup of breast cancer especially in patients with extensive intraductal carcinoma. Ductoscopic vacuum-assisted biopsy is a new and effective technique for intraductal biopsy under visual control.

Does mammary ductoscopy have a role in clinical practice?

BACKGROUND

Mammary ductoscopy (MD) is a newly developed endoscopic technique that allows direct visualisation of the mammary ductal epithelium using sub-millimetre fiberoptic microendoscopes inserted through the ductal opening onto the nipple surface. These scopes also provide working channels for insufflation, irrigation, ductal lavage, and possible therapeutic intervention. MD can be performed under local anaesthesia in the office setting. The objective of this study is to assess the technical feasibility of mammary ductoscopy, and examine its role in guiding ductal excision surgery and the early diagnosis of malignancy.

METHODS

Mammary ductoscopy (MD) was performed using a 1 mm fiberoptic microendoscope (Mastascope TM) in 26 patients (age range: 14-73 years): 13 patients undergoing mastectomy (n = 12) or lumpectomy (n = 1) for ductal carcinoma (including 12 cases of DCIS and one case of infiltrating ductal carcinoma) and 13 patients with pathological nipple discharge (PND) and benign breast imaging and simple discharge cytology. Of the latter group: 10 procedures were performed under local anaesthesia (LA) in the office setting and 3 procedures were carried out under general anaesthesia (GA) to guide duct excision surgery. The ductoscopic appearances in this group were graded between 0 and 5 (D0-D5) according to the degree of suspicion.

RESULTS

Intraoperative MD was accomplished in 11 (84.6%) of 13 patients undergoing surgery for DCIS. MD was unsuccessful in 2 cases: one patient (aged 73 years) had sclerosis of the nipple and one patient had preoperative vital blue injection in the subareolar region as part of the sentinel node biopsy thus resulting in inadequate visualisation. Intraductal pathology was visualised in 8 (80%) of the 10 cases undergoing mastectomy but ductoscopic cytology was positive for malignancy in only 2 cases (sensitivity = 16%, specificity = 100%). In the office setting, MD was accomplished in 9 (90%) out of 10 patients with PND and was well tolerated (mean pain score = 3.8 out of 10: range 0-7). Of these 10 patients; MD was inadequate (D0) in one patient due to complete occlusion of lumen by the lesion, showed a papilloma in 3 patients (D3), duct ectasia (D2) in 3 patients, irregular thickening of the lumen suspicious of DCIS (D4) in one patient and non-specific benign findings (D2) in 2 patients. Three women with benign ductoscopy and ductoscopy-assisted cytology were reassured and treated conservatively. The remaining 7 patients had ductoscopy-guided duct excision which revealed DCIS in one, papilloma in 4 and benign breast disease in 2 patients. Adequate cellular yield was obtained in 7 (70%) out of 10 cases (benign cytology). The three patients who had MD under GA during microdochectomy had benign endoscopic appearances and final histology (one papilloma and 2 cases of duct ectasia).

CONCLUSION

MD is technically feasible in most patients and has a potential in the early detection of breast cancer. The procedure can be performed safely in the office setting and should be considered in all patients presenting with a single duct PND. MD has the potential to reduce the number of duct excision procedures and minimise the extent of surgical resection. Ductoscopic cytology is not sufficiently sensitive for the diagnosis of malignancy and the development of a biopsy tool that obtains tissue under direct visualisation is required.