Ductal lavage, an advanced technique for collecting epithelial cells
from the breast milk ducts for cytologic examination, enables the
detection of premalignant and malignant cells in women who have had
normal mammograms and physical exams. That is the preliminary finding
of a new multicenter clinical trial presented at the annual
scientific meeting of the American Society of Clinical Oncologists
(ASCO) in New Orleans.
All breast cancer begins in the milk ductal system of the
breast. Ductal lavage collects breast cells directly from the milk
ducts, where breast cancer originates, said Joyce
OShaughnessy, MD, director of chemoprevention research at US
Oncology and director of cancer prevention at Baylor-Sammons Cancer
Center in Dallas, one of the sites participating in the recent
The minimally invasive ductal lavage procedure functions somewhat
like a Pap smear for the breast. By collecting and
allowing the early determination of premalignant and malignant cells
from their source, ductal lavage gives physicians both additional
information and time to counsel women about their management and
The prospective, multicenter clinical trial was conducted in one
European clinic and 20 sites in the United States. It included 495
women, with tests on 532 breasts. The women were determined to be at
high risk for breast cancerthat is, they scored a minimum of
1.7 on the Gail index, had previous breast cancer, or carried
mutations in the BRCA1 or BRCA2 gene. Investigators
required the women to have normal mammograms and physical exams
within 12 months of entering the study in order to see if ductal
lavage might identify cellular abnormalities not detected by other
standard breast diagnostic tests.
As of May 2000, ductal lavage determined the presence of abnormal
breast epithelial cells in 15% (41/271) of the high-risk women for
whom results were analyzed; 4% (11/271) were found to have markedly
abnormal cells in their breasts. Ductal lavage found atypical breast
cells in 11% of these women.
Medical follow-up is still in progress. In one case, a 2-cm
malignancy was identified in a woman who had normal mammograms both
before and after the ductal lavage procedure. By identifying the milk
duct in which the malignancy was located, ductal lavage enabled
surgeons to remove the malignancy with an excisional biopsy.
In the clinical trial, we were able to identify cell
abnormalities that place a woman at higher risk for developing cancer
before any indication could be seen on a mammogram or be felt during
a physical exam, said Dr OShaughnessy. With this
new procedure, I believe we can detect early abnormalities in breast
cells before they become cancerous.
Currently, no other minimally invasive procedure allows the detection
and localization of premalignant or malignant cells directly at the
source of breast cancer, and at such an early stage, she added.
The procedure proved easy to learn, comfortable for the women being
tested, and safe. A manual breast pump (Pro·Duct Breast
Aspirator) was used to draw fluid from the nipple and identify which
milk ducts to lavage. Previous research had demonstrated that nipple
aspirate fluid production upon nipple aspiration is associated with
roughly a doubling in breast cancer risk.
To perform the ductal lavage procedure, a flexible microcatheter
(Pro·Duct Catheter) was inserted approximately ½ inch into
the fluid-producing ducts through the natural nipple opening. A small
amount of saline solution is introduced, washing cells out of the
lining of the ducts. These cells are collected and analyzed, similar
to a Pap smear.