Accuracy of Frozen Section Analysis of Sentinel Lymph Nodes for the Detection of Asian Breast Cancer Micrometastasis - Experience from Pakistan

Abstract

Background: Intraoperative sentinel lymph node biopsy has now become the standard of care for patients with clinically node negative breast cancer for diagnosis and also in order to determine the need for immediate axillary clearance. Several large scale studies confirmed the diagnostic reliability of this method. However, micrometastases are frequently missed on frozen sections. Recent studies showed that both disease free interval and overall survival are significantly affected by the presence of micrometastatic disease. The aim of this study was to determine the sensitivity and specificity of intraoperative frozen section analysis of sentinel lymph nodes (SLNs) for the detection of breast cancer micrometastasis and to evaluate the status of non-sentinel lymph nodes (non-SLNs) in those patients subjected to further axillary sampling. Materials and Methods: We performed a retrospective study on 154 patients who underwent SLN biopsy from January 2008 till October 2011. The SLNs were sectioned at 2 mm intervals and submitted entirely for frozen sections. Three levels of each section submitted are examined and the results were compared with further levels on paraffin sections. Results: Overall 40% of patients (62/154) were found to be SLN positive on final (paraffin section) histology, out of which 44 demonstrated macrometastases (>2mm) and 18 micrometastases (<2mm). The overall sensitivity and specificity of frozen section analysis of SLN for the detection of macrometastasis was found to be 100% while those for micrometastasis were 33.3% and 100%, respectively. Moreover 20% of patients who had micrometastases in SLN had positive non-SLNs on final histology. Conclusions: Frozen section analysis of SLNs lacks sufficient accuracy to rule out micrometastasis by current protocols. Therefore these need to be revised in order to pick up micrometastasis which appears to have clinical significance. We suggest that this can be achieved by examining more step sections of blocks.

Ki67 index in intrinsic breast cancer subtypes and its association with prognostic parameters

“…All of these categories of breast cancer are uniformly considered as aggressive phenotypes of breast cancer. Moreover, significant association of ki67 index was noted with tumor grade which is considered as one of the prognostic factor in breast cancer [13, 14]. Apart from its association with tumor grade, we didn’t find any significant association of ki67 index with any other prognostic parameter including nodal metastasis.…”

Prognostic significance of p16 & p53 immunohistochemical expression in triple negative breast cancer

“…Breast cancers are quite frequent in Southeast Asia and typically associated with adverse prognostic features [ 17 – 20 ]. Multiple studies investigated the prognostic significance of p53 mutations in breast cancer.…”

Clinicopathologic features of triple negative breast cancers: an experience from Pakistan

“…Analogously a higher frequency of basal cancers was also demonstrated in Chinese women [11]. While the exact incidence of basal cancers in Pakistani population is not characterized, it is well established that frequency of reproductive age breast cancer is considerably higher than the western population [12,13]. As a reason for this happening is not known and pathologic parameters of younger age breast cancer is not well elucidated in our setup, therefore we aimed to determine the frequency and clinicopathologic parameters of triple negative breast cancers in our population which usually show a targeted racial and age preference.…”