How much clear margin is required?

[Austinite]

I was diagnosed with Stage 0 DCIS.  The original stereotactic biopsy showed extensive intermediate grade DCIS with some comedo necrosis.  I had a lumpectomy.  The pathology report showed no invasive cancer, but margins of only .8 mm and 1. mm.  I have read that DCIS requires greater margins, but my surgeon says any clear margin is sufficient.  What do you think?  Should I have a re-excision?

[Dr Santos]

The reason that your doctor may think this radiation therapy after lumpectomy is considered adequate treatment may be because there is only one area of abnormality in the breast, or he was able to remove all of the DCIS cleanly, and this is verified by mammogram after the surgery. However, If there are cancer cells present at the margin after the biopsy, definitely, an excision is usually done again to remove the remaining cancer cells.
Ultimately, your individual feelings, attitudes and values may be just as important as the facts in weighing your options. It would be best if you discuss this with your doctor. Or you can always have a second opinion from another pathologist to erase all doubts.
Take care always and keep us posted.

[Austinite]

The area of DCIS was 1.2 cm.  The path report on the sterotactic biopsy reported predominantantly a solid pattern of growth of in situ ductal carcinoma with areas of comedonecrosis showing central microcalcifications.  I am supposed to begin radiation treatments next week, but I am concerned that the very small margins are not enough. I am willing to have a re-excision if it is warranted.  

[Dr Santos]

Hi ma’am,

How are you? How big is the area of abnormality? Is t his a non-comedo type of DCIS? The initial treatment for DCIS is always surgery. Lumpectomy is a surgical procedure that removes the breast lump or suspicious tissue seen on the mammogram and some surrounding tissue as well. Lumpectomy is also called "breast sparing", "breast conserving" or "segmental mastectomy". About 95% of women with DCIS do not require a mastectomy.

Lumpectomy alone is adequate treatment if: only one area of abnormality is found on exam or on a mammogram, the area of abnormality is very small, the surgeon is able to remove the DCIS completely and no DCIS is left behind in the breast, the mammogram of the breast shows no more suspicious findings after the lumpectomy, the woman is elderly or has other serious illnesses and would not be able to tolerate more extensive surgery or breast radiation therapy, the type of DCIS is a less aggressive, or non-comedo, type and most importantly, the woman consents to close follow-up and surveillance.

You can learn more about this through this link: http://www.dcis.info/treatment-options.html

I hope this helps. Take care and keep us posted.