A "Pap Smear" for the Breast?
Ductal lavage is used to identify cancerous and precancerous cells in
the milk ducts of the breast. It has been dubbed a "Pap smear for the
breast" because, like the test for cervical cancer, it is designed to
find abnormal cells. The procedure, which can be done in a doctor's
office, involves inserting a small catheter into the ductal openings in
the nipple and washing out cells from inside the duct. The cells are
then analyzed by a pathologist who is trained to assess whether they
are normal or have begun to look abnormal in ways that indicate they
may be moving toward becoming cancerous.
Ductal lavage is
used in addition to clinical breast exams and mammography to help
high-risk women assess their risk for developing breast cancer.
Who Should Have Ductal Lavage?
Women at High Risk for Developing Breast Cancer
Ductal lavage is currently offered to women who are at high risk for
developing breast cancer. For women without a personal history of
breast cancer, risk is measured by one of several statistical models.
The Gail Model, which is used most often, looks at personal and family
factors that influence breast cancer risk. Personal factors considered
are: - Age that menstrual periods start (menarche)
- Age at time of first live birth
- Presence of a gene mutation in either the BRCA1 or BRCA2 gene
- Number of breast biopsies
- Presence of atypical ductal hyperplasia in a biopsy
Family factors that are considered include the number of first-degree
relatives that have been diagnosed with breast cancer. First-degree
relatives include mother, sisters, and daughters.
All of
this information is used to calculate the relative risk of a women
developing breast cancer in the next five years. Women who have a
relative risk equal to or greater than 1.7 percent in five years are
considered to be at high risk for developing breast cancer. This risk
is equal to that of a normal 60-year-old Caucasian woman living in
North America.
Women Who Have DCIS or LCIS
Women who have been diagnosed with ductal carcinoma in situ (DCIS) or
lobular carcinoma in situ (LCIS) are at higher risk than an average
woman for developing invasive breast cancer. Women with LCIS have a
cellular marker indicating increased risk for developing invasive
ductal cancers in both breasts. Ductal lavage may be performed in both
breasts to further define their risk. Women with DCIS are often treated
with surgery and radiation. Radiation therapy is used when a lumpectomy
is performed. Women who have had radiation can have ductal lavage
performed in the untreated breast. Women who have not had radiation may
have ductal lavage performed in both breasts, depending upon the extent
of surgery performed.
Women with a history of breast cancer
are at higher risk than the average woman for developing an invasive
breast cancer in their unaffected breast. Estimates of this risk range
from 0.5 percent to 1.0 percent per year of follow-up, depending upon
the age at diagnosis of breast cancer. Ductal lavage may be a helpful
tool, along with clinical breast exam and mammography, in finding a
second breast cancer at an early stage.
Why Do Ductal Lavage?
A cancer cell is a normal cell that has acquired mutations that cause
it to grow and divide uncontrollably. It is believed that breast cancer
cells start as normal cells that line the milk ducts. Then, through a
series of genetic changes, these cells acquire mutations that lead them
to become atypical, or abnormal, cells. Some of these abnormal cells
may go on to acquire even more abnormalities and, ultimately, to become
cancer cells.
Ductal lavage is a washing procedure that can
remove fluid found in the breast ducts. This fluid is referred to as
nipple aspirate fluid (NAF). The procedure has been dubbed "a Pap smear
for the breast" because, like the test for cervical cancer, it is a way
to find cells that are just thinking about becoming cancer.
Women with atypical cells found in NAF have been found to be at
increased risk for developing breast cancer. That's why using the
procedure, along with mammography and breast exam, can help women at
high risk for breast cancer assess their risk and make risk-reduction
treatment decisions. Ductal lavage is not a substitute for mammography
or breast exam.
How Is the Procedure Performed?
First, a numbing cream is applied to the nipple. Then, a small clear
cap with a syringe attached is placed over the nipple. This device (the
nipple aspirator) is similar to a small breast pump and is used to see
if fluid will come out of one or more of the six to eight ductal
openings in the nipple. Although the presence of ductal fluid doesn't
necessarily indicate that anything is wrong, ducts that have abnormal
cells are more likely to produce fluid than ducts with normal tissue.
Thus, the presence of fluid is an indicator that a duct should be
lavaged.
[Enlarge image]
In the second stage, an anesthetic is applied to the nipple and a
flexible, hair-thin catheter is threaded into the duct opening in the
nipple, about 1/2 inch into the fluid-producing duct. A saltwater
solution is infused through the catheter into the duct and sucked back
out. The cells that are washed out in the fluid are collected and
analyzed. The cells may be found to be normal, atypical, or malignant.
[Enlarge image]
Are There Side Effects?
Few side effects are connected with ductal lavage. Many women who have
had the procedure done say it is no more uncomfortable than a
mammogram. Some have described the sensation as "breast fullness,"
comparable to lactation. In one study two of the nearly 400 women who
had ductal lavage developed an infection that was successfully treated
with an antibiotic.
How Often Should Ductal Lavage Be Performed?
The frequency of ductal lavage depends upon the results obtained from
the first procedure. If normal ductal cells are found or if, after two
attempts at ductal lavage, there are not enough cells to make a
diagnosis, ductal lavage is repeated in one to three years. If atypical
cells are found, ductal lavage would be repeated in 6 to 12 months to
monitor these cells. If cancer cells are found, mammography, breast
magnetic resonance imaging (MRI), ductoscopy (looking in the duct with
a very small, lighted tube), or ductal surgery are options a woman
would discuss with her physician.
Who Performs Ductal Lavage?
Quite often, surgeons will perform ductal lavage. Other practitioners
performing this procedure include: medical oncologists,
cytopathologists, radiologists, nurse practitioners, and physician
assistants.
Does Insurance Pay for Ductal Lavage?
Some insurance companies cover ductal lavage. As more scientific
evidence for ductal lavage emerges, insurance companies will be more
likely to consider covering the cost of ductal lavage. In the meantime,
some centers that are performing clinical trials may have funding to
cover the cost of ductal lavage within the research setting.
How Do I Find a Center Performing Ductal Lavage?
Ductal lavage is currently available at selected centers around the country.
What Happens If Abnormal Cells Are Found?
Women who are found to have atypical cells in their ductal fluid may be
offered tamoxifen to help reduce their risk for developing invasive
breast cancer. This is known as chemoprevention.
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