Division of Breast and Melanoma Surgical Oncology, Department of Surgery, Mayo Clinic, Rochester, MN, USA.
Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA.
Ann Surg Oncol. 2022 Oct;29(10):6458-6465. doi: 10.1245/s10434-022-12195-8. Epub 2022 Jul 18.
The distinct histologic appearance of invasive lobular carcinoma (ILC) may pose diagnostic challenges for sentinel lymph node (SLN) analysis. We evaluated the impact of cytokeratin immunohistochemistry (IHC) on SLN assessment in ILC and its contribution to pathologic nodal upstaging.
We identified ILC patients treated with SLN surgery at our institution between September 2008 and August 2021. IHC for SLN assessment was employed at the discretion of the pathologist. Differences between groups evaluated with and without IHC were compared using Chi-square tests.
Overall, 608 cases of ILC were identified in patients who underwent SLN surgery. IHC was used in 301 cases (49.5%) and was not associated with cT category, pT category, or tumor grade. Use of IHC increased detection of SLN+ disease when isolated tumor cells (ITCs) were included in the analysis (35.9% with IHC vs. 21.2% without IHC; p < 0.001). There was no effect on nodal upstaging to micrometastatic disease (pN1mi) or greater (21.9% with IHC vs. 21.2% without IHC; p = 0.82). IHC did not increase the number of positive SLNs detected (median 1 with and without IHC) nor did it increase axillary lymph node dissection (ALND) rates (11.6% with IHC vs. 15.3% without IHC; p = 0.18).
IHC improved detection of pN0(i+) disease among ILC patients undergoing SLN surgery. IHC did not increase upstaging to pN1mi or higher categories of nodal disease, detection of a greater number of positive SLNs, or ALND rates. Our data suggest routine use of IHC for SLN assessment in ILC patients does not add clinical utility.
浸润性小叶癌（ILC）独特的组织学表现可能对前哨淋巴结（SLN）分析构成诊断挑战。我们评估了细胞角蛋白免疫组织化学（IHC）对 ILC 中 SLN 评估的影响及其对病理淋巴结升级的贡献。
我们在我院确定了 2008 年 9 月至 2021 年 8 月间接受 SLN 手术治疗的 ILC 患者。SLN 评估采用免疫组织化学法，由病理学家决定。使用和不使用 IHC 评估的组之间的差异使用卡方检验进行比较。
总体而言，在接受 SLN 手术的患者中发现了 608 例 ILC。301 例（49.5%）使用了 IHC，与 cT 类别、pT 类别或肿瘤分级无关。当包括孤立肿瘤细胞（ITC）时，使用 IHC 增加了 SLN+疾病的检出率（有 IHC 的为 35.9%，无 IHC 的为 21.2%；p<0.001）。对微转移疾病（pN1mi）或更高疾病的淋巴结升级没有影响（有 IHC 的为 21.9%，无 IHC 的为 21.2%；p=0.82）。IHC 既没有增加检出的阳性 SLN 数量（中位数为 1 个，有和无 IHC 时），也没有增加腋窝淋巴结清扫术（ALND）率（有 IHC 的为 11.6%，无 IHC 的为 15.3%；p=0.18）。
IHC 改善了接受 SLN 手术的 ILC 患者中 pN0(i+)疾病的检出率。IHC 并未增加 pN1mi 或更高级别的淋巴结疾病、检出更多的阳性 SLN 或 ALND 率。我们的数据表明，常规使用 IHC 进行 ILC 患者的 SLN 评估并不能增加临床实用性。
