Hi, I don't have DCIS but my experience is a partial with sentinel nodes. The results from the biopsy indicated that there were no clear margins on the tumour and that 3 of the 5 nodes were involved. I then had to go back for a full mastectomy and axillary dissection (where the surgeon took a whole bunch of nodes from under the armpit). As @brightspace said, the biopsy also gives a clear indication of hormone status. For me, this showed a greater number on the progesterone + side than the original core biopsy indicated, and gave the HER status as well.