Background: The decision to perform complete node dissection for a tumor positive sentinel node is becoming more controversial. Five year data from the American College of Surgeon's Z011 trial recently demonstrated no difference in regional control in patients undergoing sentinel node biopsy alone for node positive disease. We report our institution's 12 year experience with sentinel node biopsy alone for tumor positive sentinel node and clinicopathologic factors that are associated with sentinel node biopsy alone.

Patients and Methods: From 1998 to 2009, a retrospective review was performed on 2,139 patients who underwent sentinel node biopsy alone for breast cancer. Of these 2,139 patients, 1,997 were tumor negative, 123 tumor positive and 19 cases were undocumented. Sentinel nodes were staged node positive according to AJCC criteria. Patient and tumor factors associated with sentinel node biopsy alone and locoregional recurrence, distant recurrence and overall survival were examined. Results: One hundred twenty three node positive patients underwent sentinel node biopsy alone with no completion axillary dissection for invasive breast cancer. Eighty two (66.7%) patient's sentinel nodes had macrometastases and 41 (33.3%) had micrometastases. Median follow-up was 8 years (range0.7 to 12yrs). Mean age was 57 years (range 32-92) and stage distribution was as follows: Stage IIA: 76 (62%) patients, Stage IIB: 40 (33%) patients, Stage III: 4 patients (3%), and Stage IV: 1 patient (0.8%). The mean size of the tumors was 1.9cm (range 0.1-9), 79 patients (64%) had grade I/II tumors and 36 (29%) had grade III tumors. Eighty nine (72%) underwent lumpectomy and 34 (28%) underwent mastectomy. When we examined patient and treatment factors that might explain omission of axillary dissection we saw that 95 (77%) patients had no comorbidities, 8 (6.5%) had one comorbidity and 20 (16%) had two or more comorbidities listed. Seventy seven patients (67%) received breast radiation in combination with adjuvant chemotherapy or hormonal therapy. Ninety (73%) patients had three or less sentinel nodes removed and 33 (27%) had four or more sentinel nodes removed. One hundred twenty patients had recurrence data, of which one (0.8%) had an axillary recurrence and 13 (11%) have expired. Of the 13 patients who died, four died of metastatic breast cancer and 9 of other causes. All patients with recurrence had macrometastasis to the lymph nodes. Conclusions: Favorable tumor and patient characteristics and high prevalence of adjuvant therapy may explain why completion axillary dissection was omitted in this group of tumor positive sentinel node patients. This study represents one of the longer follow-up periods in the literature and demonstrates that recurrent regional disease is rare with extended follow-up in patients undergoing sentinel node biopsy alone for node positive disease, even macrometastatic disease.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-01-02.