Department of General and Gastrointestinal Surgery, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA.
Department of Pathology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA.
Ann Surg Oncol. 2022 Nov;29(12):7372-7382. doi: 10.1245/s10434-022-12212-w. Epub 2022 Aug 2.
Extramural vascular invasion (EMVI) is a known poor prognostic factor in colorectal carcinoma; however, its molecular basis has not been defined. This study aimed to assess the expression of molecular markers in EMVI positive colorectal carcinoma to understand their tumor microenvironment.
Immunohistochemistry was performed on tissue microarrays of surgically resected colorectal cancer specimens for immunological markers, and BRAFV600E mutation (and on the tissue blocks for mismatch repair proteins). Automated quantification was used for CD8, LAG3, FOXP3, PU1, and CD163, and manual quantification was used for PDL1, HLA I markers (beta-2 microglobulin, HC10), and HLA II. The Wilcoxon rank-sum test was used to compare EMVI positive and negative tumors. A logistic regression model was fitted to assess the predictive effect of biomarkers on EMVI.
There were 340 EMVI positive and 678 EMVI negative chemo naïve tumors. PDL1 was barely expressed on tumor cells (median 0) in the entire cohort. We found a significantly lower expression of CD8, LAG3, FOXP3, PU1 cells, PDL1 positive macrophages, and beta-2 microglobulin on tumor cells in the EMVI positive subset (p ≤ 0.001). There was no association of BRAFV600E or deficient mismatch repair proteins (dMMR) with EMVI. PU1 (OR 0.8, 0.7-0.9) and low PDL1 (OR 1.6, 1.1-2.3) independently predicted EMVI on multivariate logistic regression among all biomarkers examined.
There is a generalized blunting of immune response in EMVI positive colorectal carcinoma, which may contribute to a worse prognosis. Tumor-associated macrophages seem to play the most significant role in determining EMVI.
外膜血管侵犯（EMVI）是结直肠癌预后不良的已知因素；然而，其分子基础尚未确定。本研究旨在评估 EMVI 阳性结直肠癌中分子标志物的表达，以了解其肿瘤微环境。
对手术切除的结直肠癌标本的组织微阵列进行免疫组织化学染色，以检测免疫标志物，以及 BRAFV600E 突变（以及组织块中的错配修复蛋白）。使用自动定量法检测 CD8、LAG3、FOXP3、PU1 和 CD163，使用手动定量法检测 PD-L1、HLA I 标志物（β-2 微球蛋白、HC10）和 HLA II。采用 Wilcoxon 秩和检验比较 EMVI 阳性和阴性肿瘤。拟合逻辑回归模型评估生物标志物对 EMVI 的预测作用。
共有 340 例 EMVI 阳性和 678 例 EMVI 阴性化疗初治肿瘤。整个队列中肿瘤细胞 PD-L1 表达几乎为阴性（中位数 0）。我们发现，EMVI 阳性亚组中 CD8、LAG3、FOXP3、PU1 细胞、PD-L1 阳性巨噬细胞和β-2 微球蛋白表达显著降低（p ≤ 0.001）。BRAFV600E 或错配修复蛋白缺陷（dMMR）与 EMVI 无关。在所有检查的生物标志物中，PU1（OR 0.8，0.7-0.9）和低 PD-L1（OR 1.6，1.1-2.3）在多变量逻辑回归中独立预测 EMVI。
EMVI 阳性结直肠癌中存在普遍的免疫反应迟钝，这可能导致预后更差。肿瘤相关巨噬细胞似乎在决定 EMVI 方面起着最重要的作用。
