OBJECTIVE: This study aims to develop guidelines for size criteria in SLN evaluation for endometrial cancer, to determine whether a single cytokeratin AE1:AE3 immunohistochemical slide provides sufficient data for diagnosis, and to compare cost efficiency between current and limited ultrastaging protocols at a large tertiary care institution.
METHODS: Our current SLN ultrastaging protocol consists of cutting two adjacent paraffin block sections at two levels (L1 and L2), 50 μm apart, with two slides at each level stained with hematoxylin and eosin and cytokeratin AE1:AE3 immunohistochemistry. We retrospectively reviewed digitized L1 and L2 slides of all positive ultrastaged SLNs from patients treated for endometrial cancer between January 2013 and January 2020. SLN diagnosis was defined by measuring the largest cluster of contiguous tumor cells in a single cross section: macrometastasis (>2.0 mm), micrometastasis (>0.2 to ≤2.0 mm or >200 cells), or isolated tumor cells (≤0.2 mm or ≤200 cells). Concordance between L1 and L2 results was evaluated. Cost efficiency between current (two immunohistochemical slides per block) and proposed limited (one immunohistochemical slide per block) protocols was compared.
RESULTS: Digitized slides of 147 positive SLNs from 109 patients were reviewed; 4.1% of SLNs were reclassified based on refined size criteria. Complete concordance between L1 and L2 interpretations was seen in 91.8% of SLNs. A false-negative rate of 0%-0.9% in detecting micrometastasis and macrometastasis using a limited protocol was observed. Estimated charge-level savings of a limited protocol were 50% per patient.
CONCLUSIONS: High diagnostic accuracy in SLN interpretation may be achieved using a limited ultrastaging protocol of one immunohistochemical slide per block and linear measurement of the largest cluster of contiguous tumor cells. Implementation of the proposed limited ultrastaging protocol may result in laboratory cost savings with minimal impact on health outcomes.
目的:本研究旨在制定子宫内膜癌SLN评估的大小标准指南,为了确定单个细胞角蛋白AE1:AE3免疫组织化学载玻片是否为诊断提供了足够的数据,并比较大型三级护理机构当前和有限的超稳定方案之间的成本效率。
方法:我们当前的SLN超稳定方案包括在两个水平(L1和L2)上切割两个相邻的石蜡块切片,相距50μm,用苏木精和曙红和细胞角蛋白AE1染色每个水平的两张载玻片:AE3免疫组织化学。我们回顾性回顾了2013年1月至2020年1月期间子宫内膜癌治疗患者所有阳性超暂住SLN的数字化L1和L2切片。SLN诊断是通过测量单个横截面中最大的连续肿瘤细胞簇定义的:大转移(>2.0mm),微转移(>0.2至≤2.0mm或>200个细胞),或分离的肿瘤细胞(≤0.2mm或≤200个细胞)。评估L1和L2结果之间的一致性。比较了当前(每个块两个免疫组织化学载玻片)和建议的有限(每个块一个免疫组织化学载玻片)方案之间的成本效率。
结果:对来自109例患者的147个阳性SLN的数字化切片进行了回顾;根据精确的大小标准对4.1%的SLN进行了重新分类。在91.8%的SLN中看到了L1和L2解释之间的完全一致。观察到使用有限方案检测微转移和大转移的假阴性率为0%-0.9%。有限方案的估计费用水平节省为每位患者50%。
结论:SLN解释中的高诊断准确性可以通过每块一个免疫组织化学载玻片的有限超稳定方案和最大的连续肿瘤细胞簇的线性测量来实现。所提出的有限的超稳定协议的实施可能会导致实验室成本节省,而对健康结果的影响最小。