by Dr. C.H. Weaver M.D. updated 8/2018
A screening technique, called ductal lavage, has proven successful in detecting cancerous or pre-cancerous cells in fluid extracted from a woman’s milk duct. Because most breast cancers begin in the breast milk ducts, ductal lavage can detect cancers that are not yet seen on mammography.
The normal breast has 6 to 9 overlapping sections called lobes. Within each lobe are several smaller lobules containing cells that produce milk. The lobes and lobules are linked by thin tubes called ducts, which convey milk to the nipple in the center of the breast. Over 95% of all breast cancers originate within the milk ducts. Over a 10-year period, women with atypical cells in their milk ducts are 18 times more likely to develop breast cancer than women their same age with normal breast cells.
Several new techniques are currently under evaluation to improve screening for breast cancer in order to detect this disease early when it is most treatable. One such technique is nipple aspiration, which is used to detect abnormal cells in breast fluid by placing a suction cup over an anesthetized nipple and drawing fluid out of the milk ducts. Now, a newer test known as ductal lavage appears promising.
Ductal lavage is a safe and simple procedure that involves minimal discomfort. In fact, most women who have undergone the test report that it is less painful than a mammogram. During ductal lavage, a physician first performs nipple aspiration in order to locate the milk ducts. Then, a small, flexible needle, called a micro-catheter, is inserted about a half an inch into the milk ducts and a salt-water solution rinses cells out of the ducts. These cells are then analyzed for abnormalities. The test can be performed in an outpatient setting and is currently available at 126 institutions nationwide. Nonetheless, because of the invasiveness of the test, it is only recommended for women defined as high risk.
A recent clinical trial evaluated the effectiveness of ductal lavage as a screening procedure for breast cancer. Specifically, researchers examined whether ductal lavage could find abnormalities that were missed by standard screening tests. The study involved high-risk women who had normal mammograms within the past year. The results reported for 383 examined breasts show that ductal lavage found pre-cancerous and cancerous cells in 76 of the breasts. In two of these women, biopsies revealed ductal carcinoma in situ (DCIS) despite the fact that both of these women had normal mammograms both before and after the ductal lavage procedure. DCIS refers to cancer cells that are in the milk ducts, but have not penetrated the duct walls into the surrounding tissue. When cancer cells are found at such an early stage of development, the disease is highly curable.
Another study designed to evaluate the efficacy of ductal lavage involved 507 women with either a family history of breast cancer or previous cancer in the opposite breast. All women had non-suspicious mammograms and clinical breast exams prior to admittance to the trial. Each woman underwent nipple aspiration for an initial collection of cells, followed by ductal lavage of the fluid-yielding ducts.
The results indicated that ductal lavage yielded an average of 13,500 epithelial cells per duct, compared to only 120 epithelial cells per breast via nipple aspiration. The ductal lavage samples indicated that 24% of the women had abnormal breast cells, of which 17% were only slightly abnormal, 6% were markedly abnormal and approximately 1% were malignant (cancerous). In contrast, only 6% of the samples from nipple aspiration indicated slight abnormalities, while 3% displayed moderate abnormalities and less than 1% displayed cancer. Only very minor side effects were associated with both ductal lavage and nipple aspiration. In fact, 49% of the women rated the discomfort of ductal lavage equal to that of a mammogram.
Results of this study indicate that ductal lavage detects abnormal breast cells that cannot be detected with conventional screening measures such as mammography and/or breast examinations. This enables patients with pre-cancerous cells to intervene early and/or continue diligent screening in order to detect cancer in its earliest stages, when it is most treatable. In addition, ductal lavage detects abnormal cells 3.2 times more often than nipple aspiration and is well tolerated.
Ductal lavage may prove to be a valuable procedure for detecting DCIS. Thus far, the results support using the procedure among high-risk women. More research is needed to determine the feasibility of using ductal lavage as a standard screening procedure.
- Northwestern University’s 2ndAnnual Lynn Sage Breast Cancer Symposium, September 2000)
- Journal of the National Cancer Institute, Vol 93, No 21, pp 1624-1632, 2001)
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