Dr. MJ Bazos MD,
Management of Ductal Carcinoma in situ (DCIS)
What is DCIS?
DCIS stands for "ductal carcinoma
in situ" — a kind of cancer that is found only inside the milk ducts of
the breast. Because the cancer has not invaded tissues outside the milk ducts,
it is also called "noninvasive" breast cancer. For women who have only DCIS, the
outlook is much better than for those who have invasive cancer. However,
untreated DCIS may become invasive in time. It may grow through the duct wall to
surrounding tissue and possibly invade other parts of the body. If this happens,
the cancer is no longer DCIS and must be treated as invasive cancer. The
treatment described in this guide is for women who have only DCIS, not invasive
How common is DCIS?
Since more women in Canada are now
having screening mammograms, DCIS is being diagnosed more frequently. DCIS now
accounts for between 20% and 25% of all breast cancers detected in women who
have regular mammograms.
DCIS and invasive breast cancer are found together?
Because almost all breast cancers
start inside the milk ducts, almost every laboratory report for breast cancer
will describe some DCIS. When DCIS and invasive cancer are found at the same
time, treatment for invasive cancer will be needed.
How will I know if I have DCIS?
There are usually no warning
signs, such as a lump in the breast, when a woman has DCIS. Most often, evidence
of DCIS shows up on a mammogram taken at a screening clinic. Your doctor may
suspect that you have DCIS if "calcifications" (deposits of calcium) can be seen
on your mammogram. However, you will only know for sure that you have DCIS if a
piece of breast tissue is removed and examined in a procedure called a "biopsy."
A common kind of biopsy is a "needle" biopsy, where a small tissue sample is
removed using a needle. The sample is then examined under a microscope by a
pathologist (a doctor specializing in the examination of tissue). If the
pathologist sees typical cancer cells inside the milk ducts, then a diagnosis of
DCIS is made.
Why has my doctor
recommended a surgical biopsy?
your first biopsy was a needle biopsy that contained cancer cells, you will need
a "surgical" biopsy to find out if the cancer has invaded any of the surrounding
tissue. For this kind of biopsy, a larger amount of breast tissue is removed.
(If DCIS seems very likely, a doctor will often recommend that a surgical biopsy
rather than a needle biopsy be done first.) A surgical biopsy is crucial, since
any cancer that spreads outside the milk ducts is invasive cancer rather than
simply DCIS and will need a different kind of treatment.
When a surgical biopsy is done, the
abnormal tissue is removed in one piece and x-rayed. Samples of the tissue are
then examined under a microscope. If an x-ray of the removed tissue suggests
that all of the cancer was not removed completely, you will need a second
mammogram after your breast tissue has had a chance to heal. You may also then
need another operation to remove cancer cells left behind.
My surgical biopsy shows that I
have DCIS. What should I do next?
When you have been fully informed
of the findings from your surgical biopsy, you can begin to consider your
treatment choices. DCIS is not a fast-growing cancer, so it is quite safe to
take the time you need to consult with your doctors, family members, friends and
other women who have had breast cancer.
What is the best treatment for me?
The first thing to consider is the
possibility that the surgical biopsy did not remove all of the cancer. If there
is a chance that some cancer cells were left behind, more treatment is required.
This usually means more surgery. Your chief task will be to decide which type of
surgery is best for you.
In the past,
a diagnosis of DCIS always meant "mastectomy" (removal of the whole breast), and
this may still be the best option for some women. The other option is
"lumpectomy" (also known as "breast-conserving surgery") followed by radiation
treatment ("radiotherapy"). Lumpectomy followed by radiotherapy is now the
generally recommended treatment for early invasive breast cancer, and is also
used for DCIS.
Whether you choose
mastectomy, or lumpectomy followed by radiotherapy, survival rates are very
high: between 95% and 100% for women 10 years after surgery.
If the surgical biopsy removes all of
the cancer and no other suspicious areas for cancer are found in the breast,
then the surgical biopsy can be considered as a lumpectomy and no further
surgery is required.
should I consider when choosing between mastectomy and lumpectomy?
You will need to talk to your
doctor about the type of DCIS that was found in your breast, and how much of the
breast is involved. You will also want to consider the factors listed below:
Your concerns about appearance.
The first thing you must consider is whether you want to save the breast. This
is a very personal and individual matter. Some women want to maintain the
original appearance of their breasts if at all possible. For these women, a
lumpectomy that removes the cancer and leaves enough tissue to make the breast
look and feel natural is most desirable. Other women want to do whatever they
can to lower the chance of recurrence. These women can choose a mastectomy.
Women who choose mastectomy can consider breast reconstruction to make it
easier to live with the body changes and still feel confident that the cancer
will not return. Because the chances of controlling the cancer are excellent
either with mastectomy or with lumpectomy and radiotherapy, many women today
choose to save the breast. You will need to pick the surgical option that makes
you feel best.
The presence of
cancer cells at the cut edges of tissue removed during the surgical biopsy.
When examination of the tissue removed during the surgical biopsy shows that
there are cancer cells at the cut edges, a women choosing lumpectomy may need a
second or even third operation to remove more
If you want to avoid the
possibility of several operations, you may want to consider mastectomy. The
likelihood that the cancer will come back in the same breast. If your tumour is
large or has other features that suggest that recurrence of the cancer is likely
(e.g., cancer cells are found close to the cut edges of the removed tissue or it
is an aggressive type of cancer), you may want to consider mastectomy.
The amount of tissue to be
removed. When there is more than 1 tumour or when the tumour is large, a
lumpectomy will require the removal of a great deal of tissue. If the lumpectomy
will leave the breast disfigured, you may want to consider mastectomy, or
mastectomy followed by reconstruction of the breast.
Your ability to undergo
radiotherapy. Radiotherapy is usually recommended after lumpectomy because
it reduces the risk of the cancer coming back in the same breast. If you cannot
have radiotherapy for any reason, or if it will be very difficult or
inconvenient for you to do so because of your job or your distance from a
treatment centre, you may want to consider mastectomy. (In a small number of
cases, if the tumour is quite small and has no features indicating that it is
especially likely to return, and if it is certain that all the diseased tissue
was removed, lumpectomy without radiotherapy may be considered. You should,
however, consider this option only after fully exploring the issues with your
The possible complications
related to each procedure. All treatments carry the possibility of unwanted
side effects. Persistent pain, swelling and delayed healing of the wound can
occur with either lumpectomy or mastectomy, but they are more common with
mastectomy. The radiotherapy that follows lumpectomy can also cause unwanted
side effects, including fatigue, pain, tenderness and scarring of the breast.
Should the lymph nodes in the
armpit also be removed?
nodes (sometimes called "glands") are frequently removed for invasive breast
cancer, but not for DCIS. This is because it is very rare for cancer to spread
to the lymph nodes in DCIS, and any benefit of removal of the lymph nodes is
outweighed by the possible complications of the operation.
If I have a mastectomy for DCIS,
can the skin and nipple be kept intact for plastic surgery later?
This procedure (called
"subcutaneous mastectomy") has been done for patients with DCIS in the past
because it gives a good cosmetic result. However, because it leaves 10% to 15%
of the breast tissue behind, it only partly removes the risk of the cancer
returning and is not as safe as mastectomy. If you are choosing mastectomy to
minimize the risk that the cancer will recur, subcutaneous mastectomy is not
What about other
treatments, such as tamoxifen?
There is some scientific evidence
that treatment with tamoxifen, a drug that can prevent growth of cancer cells,
may benefit women with DCIS who have had lumpectomy. You and your doctor will
need to discuss whether the benefit of using tamoxifen outweighs any side