Importance of lymphatic mapping in ductal carcinoma in situ (DCIS): Why map DCIS?

The appropriateness of sentinel lymph node biopsy in the management of pati ents with biopsy diagnoses of duct al carcinoma in situ (DCIS) or DCIS with microinvasion (DCISM) has not been established. Three hundred forty-one pa tients presented with a biopsy diagnosis of DCIS or DCISM. Two hundred fort y (70%) underwent sentinel node biopsy at their definitive procedure. All c linical and pathologic data were collected prospectively. Of 224 patients w ith a biopsy diagnosis of DCIS 23 (10%) were upstaged to infiltrating ducta l carcinoma (IDC) at their definitive therapy and of 16 patients with a bio psy diagnosis of DCISM seven (44%) were upstaged to IDC. Excisional biopsie s were no more sensitive for detecting IDC than was core biopsy. Lymph node metastases were detected in 26 of 195 (13%) patients with a definitive dia gnosis of DCIS, in three of 15 (20%) with a definitive diagnosis of DCISM, and in eight of 30 (27%) with a definitive diagnosis of IDC. Sentinel lymph node biopsy is a valuable tool in the treatment of patients with DCIS and DCISM and is particularly needed in those undergoing mastectomy. No "high-r isk" group of patients can be identified for selective sentinel lymph node biopsy.