DCIS: Noninvasive Breast Cancer

Summary:

Breast cancer patients with DCIS have a lot of confusion about just what this diagnosis means. This short video explains DCIS, how it's different from invasive breast cancer and how it's commonly treated.  This is not intended as medical advice. Please talk to your doctor before beginning any new health practice.

Transcript:

Hello everyone.  I’m Dr. Lisa Schwartz and this is Cancer Straight Talk where you get cancer information from a cancer doctor.  Today I’m going to be talking about ductal carcinoma in situ or DCIS which is noninvasive breast cancer. 

Now all of those words might be completely new to you so let me explain.  In general, breast cancer can be divided into two types:  invasive and noninvasive.  Noninvasive breast cancer has not spread beyond the breast ducts.  It has not broken through the lining of the breast ducts to get into the tissue of the breast, the lymph nodes, or anywhere else in the body. 

An invasive breast cancer has broken through the lining of the ducts.  It is capable of invading into the breast tissue, the lymph nodes, and elsewhere in the body.  Most breast cancers are found at an early stage and even though invasive cancers are capable of invading other places, most of them have not.  Whether a breast cancer is invasive or noninvasive is determined by a pathologist looking at the cancer under a microscope.  Because DCIS cannot spread beyond the ducts and lobules of the breast, it is treated a little differently than invasive breast cancer which can spread.  In the next few minutes I’m going to cover how DCIS is discovered and the basic treatment options that you have including surgery, radiation, and hormone therapy.  My goal is to give you enough information so that you can have a discussion with your doctor and make an informed decision about the treatment that’s right for you.

DCIS is usually discovered by screening mammography.  There is nothing that you or a doctor can feel on physical exam in 90% of cases.  It commonly shows up as abnormal microcalcifications on the mammogram.  It is pretty common accounting for about 20% of all breast cancer.  Given that this disease is not invasive and limited to the breast, you might wonder why you need treatment at all.  The reason is that if nothing is done about DCIS, it can progress to invasive breast cancer.

Treatment options for DCIS are similar to the surgical and radiation treatment options for invasive breast cancer.  The main difference in treatment is that there is really no need for chemotherapy with DCIS.  I’ll talk about hormone therapy in just a moment but there is no need for cytotoxic chemotherapy.  So the surgical treatment options for DCIS are lumpectomy with radiation and mastectomy.  There is no survival difference between these two options.  So even though the mastectomy is a bigger surgery, there is no difference in survival outcomes between these two choices.

A lumpectomy is removal of the area of DCIS with a rim of normal tissue called a margin.  Since the surgeon cannot feel where the tumor is, usually the area of microcalcification is pinpointed by a radiologist before surgery.  This may be done by placing a small wire into the area of microcalcifications and having the surgeon remove the tissue surrounding the tip of the wire. There is no need to remove any lymph nodes since DCIS cannot invade into the lymph nodes.  However, there may be some special cases where a surgeon suspects that there may be invasive disease present that was not detected on biopsy.  In this case, he or she may elect to do a sentinel lymph node biopsy.  In this way we get the information about the lymph nodes with just a small added procedure which does not add much in the way of complications.

The standard of care is for the patient to receive radiation after a lumpectomy.  This can be done with external beam radiation over a few weeks with daily treatments Mon through Fri.  The radiation is delivered from a machine outside of the body, and it’s just like getting a chest x-ray.  You don’t feel the radiation at all.  The radiation can also be delivered internally by putting a radioactive pellet in the area where the tumor was.  This is called brachytherapy or APBI which stands for accelerated partial breast irradiation.  This requires placement of a device in the area of the tumor that must be left in until the radiation is complete. This next slide shows an example of the brachytherapy catheters.  The area where the balloon is or the elliptical area of the struts goes where the tumor was –an area called the tumor bed.  The catheter then extends out of the skin and is hooked up to the radiation machine for treatments.  A radioactive pellet is placed in the catheters or struts and left there for a specified amount of time to deliver a dose of radiation to the breast tissue that surrounded the DCIS.  The treatments are usually delivered twice a day over one to two weeks and then the device is removed.

Even though radiation following lumpectomy is the standard of care, there are some instances in which you could consider skipping the radiation.  The risks of this should be discussed thoroughly with your oncologist.

The other treatment option for DCIS is a mastectomy.  This is usually not necessary unless there is extensive DCIS throughout the breast or the surgeon is unable to get clear margins with a lumpectomy.  The benefit of a mastectomy is that you usually do not need radiation unless for some reason the margin was not clear after the mastectomy.  Reconstruction is always an option and can be done at the time of surgery or delayed.

After treatment with either a lumpectomy and radiation or mastectomy, your medical oncologist may also recommend Tamoxifen for 5 years.  There was a large study done, which oncologists refer to as B-17, asking the question of whether or not the addition of Tamoxifen to lumpectomy and radiation reduced the risk of breast cancer recurrence.  And the answer is “yes”.  At 15 years the risk of having breast cancer return in the same breast was reduced from 16.6% to 13.2% with Tamoxifen--so a little over 3%.  The risk of having a separate breast cancer in the opposite breast was also reduced from 8.1% to 4.9% with Tamoxifen--again a little over 3%.  So you are going to have to decide for yourself if that kind of risk reduction is worth the side effects of Tamoxifen.  And just in case these recurrence numbers sound a little high to you, keep in mind that this study was done years ago and with the advances we’ve made in surgery, radiation, and pathology, recurrence rates now would be considered to be much less than 10% with lumpectomy and radiation for DCIS.

So that’s it for our discussion of DCIS.  I hope this has been useful for you.  If you have any comments or questions, be sure to leave them below.  Click the “like” button and be sure to share this with anyone who might find the information helpful.  You can find more information about cancer and its treatment on my website at CancerStraightTalk.com.  Until next time, take care and be well.