Do sentinel node micrometastases predict recurrence risk in ductal carcinoma in situ and ductal carcinoma in situ with microinvasion?

Background Because the implications of micrometastases found on sentinel node biopsy (SNB) for ductal carcinoma in situ (DCIS) or ductal carcinoma in situ with microinvasion (DCISM) are largely unknown, we wished to determine if SNB pathology predicted recurrence risk in DCIS/DCISM. Methods Retrospective chart review identified patients with DCIS/DCISM who underwent SNB. SNB findings and all local and distant recurrences were determined. Results A total of 322 patients underwent SNB for DCIS/DCISM. There were 13 local recurrences (4.0%) and 1 (.03%) distant recurrence at a median follow-up of 47.9 months (range 0 to 110.6), 12 in patients with negative SNBs; 1 patient had a positive SNB. There were 4 recurrences after mastectomy and 9 after lumpectomy. In 29 patients with positive SNBs, there was only 1 recurrence (3.4%). Conclusions Positive SNBs in patients with DCIS or DCISM are not associated with higher risk of local or distant recurrence. Other features of DCIS and DCISM may be important in predicting recurrence risk.