Sentinel lymph node biopsy: Is it indicated in patients with high-risk ductal carcinoma-in-situ and ductal carcinoma-in-situ with microinvasion?

Background: Axillary lymph node status is the strongest prognostic indicato r of survival for women with breast cancer. The purpose of this study was t o determine the incidence of sentinel node metastases in patients with high -risk ductal carcinoma-in-situ (DCIS) and DCIS with microinvasion (DCISM). Methods: From November 1997 to November 1999, all patients who underwent se ntinel node biopsy for high-risk DCIS (n = 76) or DCISM (n = 31) were enrol led prospectively in our database. Patients with DCIS were considered high risk and were selected for sentinel lymph node biopsy if there was concern that an invasive component would be identified in the specimen obtained dur ing the definitive surgery. Patients underwent intraoperative mapping that used both blue dye and radionuclide. Excised sentinel nodes were serially s ectioned and were examined by hematoxylin and eosin and by immunohistochemi stry. Results: Of 76 patients with high-risk DCIS, 9 (12%) had positive sentinel nodes; 7 of 9 patients were positive for micrometastasrs only. Of 31 patien ts with DCISM, 3 (10%) had positive sentinel nodes; 2 of 3 were positive fo r micrometastases only. Six of nine patients with DCIS and three of three w ith DCISM and positive sentinel nodes had completion axillary dissection; o ne patient with DCIS had an additional positive node detected by convention al histological analysis. Conclusions: This study documents a high incidence of lymph node micrometas tases as detected by sentinel node biopsy in patients with high-risk DCIS a nd DCISM. Although the biological significance of breast cancer micrometast ases remains unclear at this time, these findings suggest that sentinel nod e biopsy should be considered in patients with high-risk DCIS and DCISM.