Wide Excision Only for DCIS?

When is it appropriate to treat DCIS with wide excision alone, as opposed to wide excision followed by radiation?  Is it to do with the size of the affected area and/or the grade of the DCIS as shown from the biopsy? Or, are there are other factors at play?

Thank you.

[Fernando Roque, MD]

Hi.  According to the latest National Comprehensive Cancer Network (NCCN) guidelines, the recommended treatment for ductal carcinoma in situ (DCIS) is either mastectomy alone or lumpectomy plus radiation.  Radiotherapy is added to the lumpectomy because it decreases local recurrence rates by 50% compared to lumpectomy alone.  Wide excision is NOT equivalent to lumpectomy (lumpectomy is a more extensive type of surgery), and is not the recommended procedure for treating DCIS.

Lumpectomy alone, without subsequent radiotherapy, may be an appropriate treatment if the DCIS is considered to have a "low risk" of recurrence. The risk of recurrence depends on certain factors such as size, tumor grade, age of patient and status of surgical margins.  "Low risk" refers to a tumor which is small, with low tumor grade, and negative surgical margin, occurring in older patients.

[Strike3]

Dr. Roque:

Thank you for your answer. One more question - as DCIS is not really a lump, or tumor - how do you measure the size of the affected area? And, what is considered "small?"

Thank you again for taking the time to respond.  It is very helpful.

[Fernando Roque, MD]

Hi.  With ductal carcinoma in situ, "size" would refer to the extent of spread of the DCIS within the ducts. This is determined by microscopic examination of the breast tissue after excision.  With DCIS, the cancer has not yet invaded or penetrated through the ducts, but it is possible for the cancer to "creep" within the ducts and involve a sizable area.