Biopsy findings after breast conservation therapy for early-stage invasive breast cancer.

PURPOSE: To determine the patterns and factors predictive of positive ipsilateral breast biopsy after conservation therapy for early-stage breast cancer. METHODS AND MATERIALS: We performed a retrospective review of Stage I-II breast cancer patients initially treated with lumpectomy and radiotherapy between 1977 and 1996, who later underwent post-treatment ipsilateral breast biopsies. RESULTS: A total of 223 biopsies were performed in 193 treated breasts: 171 single and 22 multiple biopsies. Of the 223 biopsies, 56% were positive and 44% were negative for recurrence. The positive biopsy rate (PBR) was 59% for the first and 32% for subsequent biopsies. The median time to the first post-treatment biopsy was 49 months. Of the patients with negative initial biopsy findings, 11% later developed local recurrence. The PBR was 40% among patients with physical examination findings only, 65% with mammographic abnormalities only, and 79% with both findings (p = 0.001). Analysis of the procedure type revealed a PBR of 86% for core and 58% for excisional biopsies compared with 28% for aspiration cytology alone (p = 0.025). The PBR varied inversely with age at the original diagnosis: 49% if >or=51 years, 57% if 36-50 years, and 83% if 180 months after completing postlumpectomy radiotherapy (p = 0.01). The PBR was not linked with recurrence location, initial pathologic T or N stage, estrogen receptor/progesterone receptor status, or final pathologic margins (all p >or= 0.15). CONCLUSION: After definitive radiotherapy for early-stage breast cancer, a greater PBR was associated with the presence of both mammographic and clinical abnormalities, excisional or core biopsies, younger age at the initial diagnosis, and longer intervals after radiotherapy completion.

The association of cytokeratin-only-positive sentinel lymph nodes and subsequent metastases in breast cancer.

INTRODUCTION: The purpose of this study was to better characterize the clinical significance of cytokeratin immunohistochemistry (IHC)-only-positive lymph node metastases among patients with breast cancer. METHODS: We performed a retrospective review of 334 patients who underwent sentinel lymph node (SLN) biopsy from 1 February 1997 through 31 July 2001. SLN biopsies were evaluated using standard hematoxylin and eosin (H&E) techniques. If H&E was negative, cytokeratin IHC was performed. We then evaluated the incidence of subsequent regional and distant metastatic disease. RESULTS: Cytokeratin IHC was performed on 183 sentinel node biopsies from 180 patients comprising a total of 427 sentinel lymph nodes. The procedures included lumpectomy and SLN biopsy (n = 83), mastectomy with SLN biopsy (n = 7), lumpectomy with SLN biopsy and completion axillary dissection (n = 80), and modified radical mastectomy with SLN biopsy and completion axillary dissection (n = 13). Cytokeratin IHC was negative in 175 axillary specimens and positive in 8 (4.4%) from 8 different patients. In these eight specimens, deeper sections with subsequent H&E staining additionally identified micrometastasis in four patients. Three of these 8 patients (37.5%) developed distant metastatic disease compared with 1 of the 172 patients (0.6%) with negative cytokeratin IHC (P < .001). Additionally, one of the cytokeratin-positive patients developed regional nodal metastasis compared with none of the 172 cytokeratin-negative patients. CONCLUSIONS: Cytokeratin IHC provides a clinically relevant adjunct to H&E staining for evaluating sentinel lymph nodes in breast cancer. These data suggest that patients with cytokeratin-positive sentinel nodes are at increased risk for development of regional and distant metastatic disease.