Sentinel lymph node biopsy is not necessary in patients diagnosed with ductal carcinoma in situ of the breast by stereotactic vacuum-assisted biopsy.

BACKGROUND: This study evaluated the role and need of a sentinel lymph node biopsy (SLNB) in patients with an initial diagnosis of ductal carcinoma in situ (DCIS) made by stereotactic vacuum-assisted biopsy (VAB). MATERIALS AND METHODS: A retrospective analysis was performed of 1,458 patients who underwent stereotactic VAB between January 1999 and December 2012 at Aichi Cancer Center Hospital. The rates of axillary node metastasis and the underestimation of invasive ductal carcinoma (IDC) were examined. RESULTS: Of the 1,458 patients who underwent stereotactic VAB, 199 had a preoperative diagnosis of DCIS and underwent surgery. In these patients, 20 % (39/199) were upstaged to IDC or at least microinvasion in final pathology. Axillary lymph node status was investigated in 81 % (161/199) of initially diagnosed DCIS patients, and resulted in finding lymph node metastasis in 0.62 % (1/161) patients. To assess the potential preoperative predictors of invasiveness, the value of DCIS histological grade on biopsy samples, the distribution of calcifications on mammograms, and the combination of these factors were studied. The underestimation rate was higher (30 %) in the combination of high DCIS histological grade and extensive calcification although there was no significant association (p = 0.23). CONCLUSION: The rate of lymph node metastasis was extremely low (0.62 %), even when invasive carcinoma was identified on excision in patients initially diagnosed with DCIS by stereotactic VAB. Because of the low prevalence of metastatic involvement, the cessation of SLNB is a reasonable consideration in patients initially diagnosed with DCIS by stereotactic VAB.

High recurrence risk and use of adjuvant trastuzumab in patients with small, HER2-positive, node-negative breast cancers.

BACKGROUND: Five randomized trials of adjuvant trastuzumab have reported significant improvements in recurrence-free survival (RFS) and overall survival. However, patients with node-negative tumors 1 cm or smaller were excluded from these trials. We assessed the recurrence risk and benefit of adjuvant therapy in such patients with small tumors. METHODS: We identified patients with node-negative breast tumors 1 cm or smaller between April 2003 and December 2007. Patients were categorized according to HER2 status and pathological tumor size (pT <5 mm vs. 5-10 mm), hormone receptor (HR) status and adjuvant chemotherapy. The primary endpoint was RFS. RESULTS: Of 267 patients included in the analysis, 42 had HER2-positive tumors. The median follow-up was 4.3 years. RFS was worse in patients with HER2-positive tumors than HER2-negative tumors (90.5 vs. 97.7% at 5 years; P = 0.031). In the group with HER2-positive tumors, there were no recurrences in patients with pT<5 mm, but 4 recurrences in those with pT 5-10 mm. RFS was worse in patients with pT 5-10 mm than pT <5 mm (79.0 vs. 100%, P = 0.025). Furthermore 3 recurrences occurred in patients without adjuvant trastuzumab, and 1 recurrence occurred as soon as adjuvant trastuzumab was finished. Our results appear to establish the efficacy of adjuvant trastuzumab therapy. HR status and use of adjuvant chemotherapy were not significantly associated with RFS. CONCLUSIONS: Patients with HER2-positive, node-negative breast tumors 1 cm or smaller (especially 0.5-1.0 cm) have a significant recurrence risk and the decision to employ adjuvant trastuzumab therapy should be discussed with patients based on our results and those of other studies.