What is ductal carcinoma in situ (DCIS)?
As
more women have gotten mammograms on a regular basis, DCIS has been
found far more often. DCIS is a noninvasive precancer. It is not life
threatening. If you have DCIS, it means that you have abnormal cells in
the lining of a duct. While virtually all invasive cancer begins as
DCIS, not all DCIS will go on to become an invasive cancer. An invasive
cancer is one that has the potential to metastasize (spread). Right now
we have no way to determine which DCIS will go on to become invasive
cancer and which will not. That's why doctors recommend DCIS be
treated.
[Enlarge image]
DCIS
appears as microcalcifications on a mammogram. When these
microcalcifications are seen, it is recommended that a woman have a
core biopsy or a wire localization biopsy. This will determine whether
you actually have DCIS. If you do, the next step should always be to
have another mammogram to see if the biopsy has gotten rid of all the
microcalcifications, as no matter how thorough your surgeon has been,
there still may be a few remaining. If the diagnosis is DCIS, make sure
your pathology report
includes information about the grade, presence of necrosis, margin, and
estrogen receptor. This information is needed to determine how to treat
the DCIS.
How is it treated?
The options
for treating DCIS are: breast conservation surgery, breast conservation
surgery and radiation, a combination of those with tamoxifen, or
mastectomy. You don't have to rush into any one treatment because your
doctor or your friend or anyone else says you should. It's your breast,
and your life. Take the time to decide what's best for you.
Surgery
The
goal of treating DCIS is prevention. As long as the precancer is
completely removed, it can neither come back nor become invasive.
Currently not all doctors are in agreement about the best way to treat
DCIS. Most women undergo breast conservation surgery. However, if the
DCIS is throughout the breast, a mastectomy will probably be necessary.
You can learn more about mastectomy and reconstructive surgery in our
feature story, "Breast Reconstruction— What You Need to Know."
The
breast conservation surgery will be done with a wide excision, which
means taking out the microcalcifications along with a centimeter-wide
rim of normal tissue around it. Sometimes this is done in the first
operation and other times it is necessary to go back and remove more
tissue (a re-excision). There is no reason to remove lymph nodes for
small areas of DCIS since precancer can't spread at this stage. But if
the lesions are big (greater than 5cm), some experts think they may
hide microinvasion and recommend removing the lymph nodes as well.
Radiation
There
is currently a controversy about whether radiation is necessary
following breast conservation surgery. To date, three randomized
controlled studies have compared surgery alone to surgery and radiation
for DCIS. Most of the women in these studies had small lesions that
were removed with clean margins. At five years of follow-up, surgery
alone had about a 16 percent risk of recurrence while surgery with
radiation therapy had an 8 percent risk. About 50 percent of the local
recurrences were invasive cancer and 50 percent were more DCIS. Some
surgeons believe that this low recurrence rate means that if the DCIS
was removed with a nice, clean margin, radiation isn't necessary.
Others believe that radiation is necessary because the DCIS can recur,
and it can recur as an invasive cancer. The National Comprehensive Cancer Network treatment guidelines
recommend that radiation only be skipped if the margins are negative
and the tumor is low grade and small (less than 1/5 inch).
Hormone Therapy
Since
DCIS is not capable of spreading, there is no reason to use
chemotherapy. However, if the DCIS is ER-positive you will need to
consider whether you want to take tamoxifen for five years to reduce
your risk of a recurrence. The decision to take tamoxifen for DCIS is a
difficult one for many women, as the benefits from taking it are small
and have to be weighed against the risks associated with the drug as
well as any side effects you may experience. Before you make your
decision, you should request that the DCIS be tested for estrogen
receptors as there is data from a small study that suggests that women
whose DCIS is not hormone-sensitive do not benefit from tamoxifen.
|
|
 |
|
