Is Breast-conserving or Breast-removing Treatment Right for You?

If you have more than one area of DCIS in the breast, some doctors might automatically recommend mastectomy. That's because no studies have proven that breast-conserving treatment for more than one cancer is as effective as removal of the whole breast. The studies are hard to do. It's difficult to gather enough women in this situation and give half of them breast-preservation therapy, the other half mastectomy, and then compare the results over time in a clinical trial.

But this doesn't mean you definitely need mastectomy if you have more than one area of DCIS. If you feel strongly about keeping your breast, talk to your doctor about your options.

Whether breast-conserving treatment is right for you will depend on the size of the DCIS, whether there is more than one area of DCIS, and the margins of resection. Here are some examples of situations that might influence the decision:

When breast-conserving treatment may be better than breast-removing:

• You have two small- to medium-sized areas of DCIS close together in the same section of the breast, completely removed with clear margins: It is reasonable to consider breast-conserving therapy with lumpectomy and radiation. A mammogram after surgery may be important to be sure the areas of abnormality have been completely removed.
• You have two small- to medium-sized areas of DCIS in different sections of the breast and no other signs of abnormality (judged by high-quality mammography and MRI scan): Breast-conserving therapy may be an option. Both areas have to be completely removed with clear margins, and that might take two lumpectomies and sometimes re-excisions. A mammogram after surgery may be important to help prove complete removal of the areas of abnormality. After surgery, you will need whole breast radiation. (Partial breast radiation is not right for women with more than one cancer in the breast.)

When the choice is not clear and needs further evaluation:

• You have a small- to medium-sized area of DCIS but multiple positive margins: It's worth doing a re-excision to get around the problem with clear margins. If you still have a positive margin after the re-excision, your doctor may need to do another re-excision of the single positive margin. After that surgery, and with a clear post-surgery mammogram, you and your doctor will be better able to decide whether breast-conserving surgery is right for you.
• You have a medium-sized DCIS and multiple positive margins after lumpectomy or re-excision: You'll need to be further evaluated before you and your doctor can decide whether you can have breast-conserving treatment.

When breast-removing treatment may be better than breast-conserving:

• There is DCIS throughout your breast or it covers a large area or multiple areas of your breast
• You have a proven breast cancer gene abnormality, such as BRCA1 or BRCA2, along with a diagnosis of DCIS. This is a reason for you and your doctor to be aggressive and choose a mastectomy, even if the cancer is small.
• The pathology report shows DCIS throughout a large area of breast tissue, with positive margins, even though your mammogram only shows a medium-sized area of abnormality. In addition, your mammogram shows many microcalcifications throughout the breast.
• Your MRI scan shows a large area of abnormality going far beyond the DCIS demonstrated by the biopsy. This means that the contrast dye injected into your veins before the MRI scan collected in a specific area. The MRI scan report calls this an area of "enhancement." Cancer involvement is possible there.
• You have multiple areas of abnormality in different parts of the breast, as seen on imaging studies and from pathology results.
• You had a medium-to-large area of breast tissue removed, and high-grade DCIS was found throughout the tissue.
• You had a medium-to-large area of breast tissue removed, and there were multiple positive margins. Here, it may be unrealistic to expect that re-excision can get clear margins around the problem.

The above situations have one thing in common: The DCIS occupies a medium-to-large part of the breast. The whole area of abnormality has to be removed to be sure to remove all of the DCIS. But removing such a large area of DCIS might leave very little breast tissue behind. In this situation, mastectomy may improve your chance of getting rid of all the breast cancer. And mastectomy with reconstruction might give you the most satisfactory-looking breast. There are also many women who choose mastectomy without reconstruction.