How the Extent of DCIS Affects Treatment Options

Before a decision can be made about whether you can have breast-conserving or breast-removing treatment, your doctor has to put together a picture of what this particular cancer looks like and how it is likely to behave.

Your treatment for DCIS will depend on four factors:

1. the extent of the DCIS, including the areas of involvement, cancer size, margins of resection, results of post-biopsy radiology testing, and presence of a bloody nipple discharge
2. the "personality" of the DCIS, including cancer grade, whether there are dead cells in the tumor, the pattern of growth, the presence or absence of microinvasion, and hormone receptor status
3. family history of breast cancer
4. aspects of your unique personal situation

Extent of the DCIS

Diagnostic techniques such as mammography, ultrasound, and MRI scanning help define how much DCIS is in the breast and where it is. The DCIS may show up around microcalcifications with or without a lump.

Areas of involvement

Does the DCIS involve one or more sites in the breast—and how close or far are they from each other?

• Uni-focal disease means there is one area of DCIS in one quadrant.
• Multi-focal disease means more than one area of DCIS in one quadrant.
• Multi-centric disease means more than one quadrant is involved.

If there is more than one area of involvement, your doctor will want to know:

• if only one quadrant is involved (multi-focal disease)
• if more than one quadrant is involved (multi-centric disease)
• the distance between the areas of involvement

Careful testing is important to define the extent of the disease before surgery. It's also important to have careful testing after surgery to make sure that the area of abnormality is completely removed.

Cancer size

The extent of DCIS is also determined by the size, which is usually given in the pathology report. Knowing the size of the DCIS can help you and your doctor pick the best treatment for you.

The piece of breast tissue removed for analysis is called the specimen. You can find the size of the specimen under the "gross pathology" section of the report. It might say "5.0 x 4.5 x 3.0 cm" ("cm" means "centimeters"), for example. Sometimes, the pathology report might give a tumor size—for example, "1.2 x 1.0 x 0.5 cm"—and also state, "DCIS is seen throughout the specimen." This means that the whole area of abnormality (the main area of DCIS plus the scattered DCIS) might add up to 5.0 x 4.5 x 3.0 cm.

If you had a re-excision (a second surgery to remove any suspicious area that remained after the first surgery), and the re-excision also has DCIS in it:

• If the areas of involvement were right next to each other, their sizes are added together.
• If the areas of involvement were separated, they are given separate sizes and considered multi-focal or multi-centric disease.

A final tumor size is assigned when

• the whole DCIS has been removed
• margins of resection are clear
• the area of abnormality on the mammogram is gone

With DCIS, size has no impact on stage - this is unlike invasive breast cancer where size and stage are related. DCIS is always Stage 0, but it can be any size and be located in any number of areas inside the breast.

The size and extent of DCIS do have an impact on how the breast will be treated. For example, small cancers that can be completely removed can be treated by breast-conserving therapy. Extensive DCIS covering a large part of the breast may require mastectomy.

When you and your doctor are sure that the whole DCIS has been removed, then you can calculate the final tumor size. Review your pathology report with your doctor to define the extent of the problem.

Margins of resection

The margins of resection can also give information on the extent of disease. For example, if the DCIS is "1.2 x 1.0 x 0.5 cm" but several margins of resection are positive or very close, then the DCIS might be bigger than the actual measurement suggests. If the margins of resection are positive, your doctor may recommend a re-excision.

The definition of a negative margin varies from one hospital to another. But most pathologists agree that a margin of at least two millimeters is best. The wider the clear margin, the lower the risk of the cancer coming back. A re-excision may be necessary to get clear margins.

Post-biopsy radiology testing

If the DCIS was discovered around an area of clustered microcalcifications, then it's common to do a "post-biopsy mammogram" of the affected breast about two weeks after surgery. This will show whether the microcalcifications are all gone.

If you're worried that having a mammogram done on a tender breast right after surgery might hurt, you can ask your doctor for some pain medication before the test to make it easier for you. Also, ask to have the most experienced mammogram technologist do the study so it goes faster.

If the pathology report shows a significant area of involvement with positive margins, more scans can help to figure out whether there are additional abnormal areas in the breast. Sometimes an MRI scan may be recommended to sort this out.

If there is no evidence of additional abnormalities, then a re-excision makes sense. If there are several suspicious areas of abnormality and you still want to keep your breast if at all possible, then these new areas have to be evaluated. But understand that if the DCIS is already extensive, margins are positive, and the post-lumpectomy scans show more areas of concern, your doctor may recommend mastectomy.

Bloody nipple discharge

If blood comes out of the nipple, it can mean that there are cancer cells in or along the main milk ducts that drain out through the nipple. An MRI scan of the breast can tell whether there are other areas of DCIS and whether they are separate or connected. If there is extensive DCIS of the main ducts of the breast, then mastectomy is usually recommended. But if the DCIS is only in one area and the bloody discharge is only coming from that area, then breast-conserving treatment is usually possible.