Division of Anatomic Pathology, Department of Pathology and Laboratory Medicine, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Halifax, Nova Scotia, Canada.
Department of Medical Science, Faculty of Science, Dalhousie University, Halifax, Nova Scotia, Canada.
Clin Breast Cancer. 2019 Aug;19(4):286-291. doi: 10.1016/j.clbc.2019.03.002. Epub 2019 Mar 11.
The practice of performing routine cytokeratin immunohistochemistry (CK-IHC) on sentinel lymph nodes in early stage invasive breast cancer leads to frequent identification of isolated tumor cells (ITCs), the clinical significance of which remains unclear. After emergence of guidelines that suggested limited clinical utility of ITC detection, routine CK-IHC (rCK-IHC) staining was discontinued at our institution. We studied the rate and clinical utility of ITC detection before and after the discontinuation of rCK-IHC.
We retrospectively reviewed 2 cohorts of 250 consecutive early stage invasive breast cancer (IBC) patients with sentinel lymph node biopsies (SLNBs) in 2010 to 2011 (rCK-IHC) and 2015 to 2016 (selective CK-IHC [sCK-IHC]). Variables abstracted included: tumor histology, tumor size, grade, lymphatic-vascular invasion, hormone receptor expression, HER2 status, and nodal status including ITCs. All cases from the 2015 to 2016 cohort for which sCK-IHC was performed underwent pathology review. A clinical review of treatment decision effect and cost analysis was undertaken. Data were analyzed using descriptive statistics and Fisher exact test.
In the rCK-IHC cohort, all 250 cases underwent CK-IHC staining versus 57 cases in the sCK-IHC cohort. There were 23 ITC cases observed in the rCK-IHC cohort compared with 11 in the sCK-IHC cohort (P = .049). Excluding lobular carcinomas, 19 ITC cases were observed with rCK-IHC versus 7 with sCK-IHC (P = .02). ITC detection did not affect adjuvant treatment decision-making and resulted in savings of at least Can$8000.
Selective rather than routine use of CK-IHC staining for SLNB evaluation in early-stage IBC results in decreased ITC detection without affecting treatment decisions and leads to cost savings.
在早期浸润性乳腺癌的前哨淋巴结中进行常规细胞角蛋白免疫组化（CK-IHC）检测会导致频繁发现孤立肿瘤细胞（ITC），但其临床意义尚不清楚。在指南建议 ITC 检测的临床应用有限之后，我们医院停止了常规 CK-IHC（rCK-IHC）染色。我们研究了在停止 rCK-IHC 前后检测 ITC 的发生率和临床应用。
我们回顾性分析了 2010 年至 2011 年（rCK-IHC）和 2015 年至 2016 年（选择性 CK-IHC[sCK-IHC]）接受前哨淋巴结活检（SLNB）的 250 例连续早期浸润性乳腺癌（IBC）患者的 2 个队列。提取的变量包括：肿瘤组织学、肿瘤大小、分级、淋巴血管侵犯、激素受体表达、HER2 状态以及包括 ITC 在内的淋巴结状态。对 2015 年至 2016 年队列中所有进行 sCK-IHC 检测的病例进行了病理复查。对治疗决策效果和成本分析进行了临床评估。数据采用描述性统计和 Fisher 确切检验进行分析。
在 rCK-IHC 队列中，所有 250 例均进行 CK-IHC 染色，而 sCK-IHC 队列中仅 57 例进行 CK-IHC 染色。rCK-IHC 队列中观察到 23 例 ITC 病例，而 sCK-IHC 队列中观察到 11 例 ITC 病例（P=0.049）。排除小叶癌后，rCK-IHC 观察到 19 例 ITC 病例，sCK-IHC 观察到 7 例 ITC 病例（P=0.02）。ITC 检测并未影响辅助治疗决策，至少节省了 8000 加元。
在早期 IBC 中，选择性而非常规使用 CK-IHC 染色对 SLNB 进行评估，可减少 ITC 检测，而不影响治疗决策，并可节省成本。
