Background: Colorectal carcinomas (CC) are one of the most commonly diagnosed malignancies. Tumor budding (the histologic process of dissociation that occurs at the invasive margin of colorectal cancer), has significant prognostic implications, in that higher tumor budding is associated with adverse histopathologic and clinical outcomes. Because of this prognostic significance, more research is needed to further understand the pathologic and immunohistochemical (IHC) associations pertaining to this important prognostic variable. In this study, we will further evaluate selective clinopathologic and IHC variables with possible association to tumor budding. Design: A total of 234 cases of CC diagnosed in our health system were retrospectively reviewed and routine hematoxylin and eosin–stained slides of these cases were collected. A representative slide for tumor budding was selected per case and selective IHC staining was performed. Clinicopathologic data were collected for each case and analyzed in relation to tumor budding scores. In exploratory analyses, tumor budding scores per individual investigator and consensus tumor budding scores were compared with selected IHC stains (MLH1, PMS2, and PHH3) as well as numerous clinicopathologic variables. Results: We found a paradoxical association between tumor budding and mitosis score using PHH3 immunostaining in univariate and multivariable analysis. Furthermore, patients with intact nuclear expression for MLH1 and/or PMS2 are more likely to have higher tumor budding compared with patients with lost expression. For multivariable analysis, the following covariates were significantly associated with higher tumor budding: the presence of lymphovascular invasion, higher pathologic tumor stage, and finally infiltrating border was more likely to be associated with higher tumor budding compared with cases with a pushing border. Regarding nonmucinous versus mucinous CC, nonmucinous adenocarcinoma (MCA) was more likely to be associated with higher tumor budding compared with MCA. Conclusion: Numerous clinicopathologic variables were found to be associated with tumor budding including lymphovascular invasion, tumor stage, infiltrating tumor border, non-MCA was more likely to be associated with higher tumor budding compared with MCA, possibly related to MUC-2 and MSI. Furthermore, regarding the paradoxical association between tumor budding and mitosis score using a PHH3 immunostaining (high tumor budding having lower mitosis), this is possibly related to the tumoral stomal microenvironment and cancer associated fibroblasts. An idea for a future study would be to look at the maturity of cancer-associated fibroblasts (immature vs. mature) and the tumoral stroma microenvironment, with regards to markers of tumor aggressiveness such as mitosis. In addition, we found that patients with intact nuclear expression for MLH1 and/or PMS2 were more likely to have higher tumor budding compared with patients with lost expression, possibly related to mismatch repair CC’s not being as reliant on tumor budding. Future research will hopefully concede further insight into the variables that affect tumor budding, especially regarding the tumoral microenvironment and variations between different patient populations, inclusive of patients lacking activity of the mismatch repair. Ultimately, this will allow for better prognostic information, and more precise treatment modalities.

中文翻译：

---

结直肠癌中的肿瘤萌芽显示出反常的有丝分裂指数（通过 PHH3），可能与肿瘤基质微环境相关

背景：结直肠癌（CC）是最常见的恶性肿瘤之一。肿瘤出芽（发生在结直肠癌浸润边缘的组织学分离过程）具有重要的预后意义，因为较高的肿瘤出芽与不良的组织病理学和临床结果相关。由于这种预后意义，需要更多的研究来进一步了解与这一重要预后变量有关的病理和免疫组织化学 (IHC) 关联。在这项研究中，我们将进一步评估可能与肿瘤出芽相关的选择性临床病理学和 IHC 变量。设计：对我们卫生系统中诊断出的总共 234 例 CC 进行回顾性审查，并收集这些病例的常规苏木精和伊红染色切片。每个病例选择肿瘤出芽的代表性载玻片并进行选择性 IHC 染色。收集每个病例的临床病理数据，并根据肿瘤出芽评分进行分析。在探索性分析中，将每位研究者的肿瘤出芽评分和共识肿瘤出芽评分与选定的 IHC 染色（MLH1、PMS2 和 PHH3）以及众多临床病理变量进行了比较。结果：我们在单变量和多变量分析中使用 PHH3 免疫染色发现肿瘤出芽和有丝分裂评分之间存在矛盾的关联。此外，与失去表达的患者相比，具有完整核表达 MLH1 和/或 PMS2 的患者更有可能具有更高的肿瘤出芽。对于多变量分析，以下协变量与较高的肿瘤出芽显着相关：与具有推动边界的病例相比，存在淋巴血管侵犯、较高的病理肿瘤分期和最终浸润边界更可能与较高的肿瘤出芽相关。关于非粘液性与粘液性 CC，与 MCA 相比，非粘液性腺癌 (MCA) 更可能与更高的肿瘤出芽相关。结论：发现许多临床病理变量与肿瘤出芽相关，包括淋巴血管浸润、肿瘤分期、浸润性肿瘤边界，与 MCA 相比，非 MCA 更可能与更高的肿瘤出芽相关，可能与 MUC-2 和 MSI 相关。此外，关于使用 PHH3 免疫染色（高肿瘤出芽具有较低有丝分裂）的肿瘤出芽和有丝分裂评分之间的矛盾关联，这可能与肿瘤造口微环境和癌症相关的成纤维细胞有关。未来研究的一个想法是研究癌症相关成纤维细胞的成熟度（未成熟与成熟）和肿瘤基质微环境，关于肿瘤侵袭性的标志物，如有丝分裂。此外，我们发现与缺失表达的患者相比，MLH1 和/或 PMS2 完整核表达的患者更有可能具有更高的肿瘤出芽，这可能与错配修复 CC 不依赖于肿瘤出芽有关。未来的研究有望进一步深入了解影响肿瘤出芽的变量，特别是关于肿瘤微环境和不同患者群体之间的差异，包括缺乏错配修复活动的患者。最终，