Cribriform colon cancer: a morphological growth pattern associated with extramural venous invasion, nodal metastases and microsatellite stability

Emerging and under-recognised patterns of colorectal carcinoma morphologies: a comprehensive review

While the overwhelming majority of colorectal carcinomas (CRC) are diagnosed as adenocarcinoma not otherwise specified, there are numerous under-recognised morphologic patterns of CRC. These patterns are recognised by the WHO, appear in reporting manuals for the American Joint Committee of Cancer, and/or are listed on synoptic reports, while many other variants have either fallen out of favour or are emerging as future bona fide patterns. Herein, we discuss 13 variants: serrated adenocarcinoma, micropapillary adenocarcinoma, medullary carcinoma, neuroendocrine carcinoma, mucinous adenocarcinoma, signet-ring cell carcinoma, adenosquamous carcinoma, adenoma-like adenocarcinoma, lymphoglandular complex-like CRC, carcinoma with sarcomatoid components, cribriform-comedo-type adenocarcinoma, undifferentiated carcinoma and low-grade tubuloglandular adenocarcinoma. The purpose of this review is to scrutinise these variants by assessing their clinical characteristics, morphologic cues, as well as pitfalls, and address their prognostic significance. Our analysis aims to bring clarity and updated understanding to these variants, offering valuable insights for pathologists. This contributes to more nuanced CRC diagnosis and treatment strategies, highlighting the importance of recognising a broad spectrum of morphologic patterns in CRC.

Clinicopathological features and evaluation of microsatellite stability of colorectal carcinoma with cribriform comedo pattern

BACKGROUND

Cribriform comedo-type adenocarcinoma (CCA) was a colon cancer subtype defined in the 2009 World Health Organization (WHO) classification. In the 2018 classification, it was a colon cancer subtype included in the adenocarcinoma, Not otherwise specified (NOS) group. A few studies have reported that colon cancers with a cribriform pattern have worse overall survival, and most of them are microsatellite stable (MSS). In this study, we evaluated CCAs based on their clinicopathologic features and microsatellite stability. We aimed to answer whether these tumors could be defined as a distinct morphologic subtype with prognostic significance.

MATERIALS AND METHODS

Pathology reports and specimens from 449 patients with colorectal adenocarcinoma (CRA) were re-evaluated. All subtypes were determined. To evaluate MSS status, the CCA cases were immunohistochemically stained with anti-MLH1, MSH2, MSH6, and PMS2 antibodies.

RESULTS

CCA was present in 40.5% of cases. These cases were found to have higher rates of lymph node metastasis, lymphovascular-perineural invasion, metastasis, and advanced stage ( P < 0.05). Also, 2.7% of CCA cases were microsatellite instable (MSI). However, no statistically significant result was found regarding overall survival and progression-free survival of CCA cases with MSI.

CONCLUSION

According to the findings, CRAs with comedo cribriform patterns are tumors with more aggressive features. It can be said that these tumors have a specific molecular feature related to MSS. Because this feature is important for planning adjuvant chemotherapy, it may be useful to identify cases, particularly with a cribriform comedo pattern >90%. However, because no significant difference in survival rates was found, CCAs may not need to be defined as distinct subtypes.

Immune function status of postoperative patients with colon cancer for predicting liver metastasis

BACKGROUND

Colon cancer (CC) has a high incidence rate. Radical resection is the main treatment method for CC; however, liver metastasis (LM) often occurs post-surgery. The liver contains both innate and adaptive immune cells that monitor and remove abnormal cells and pathogens. Before LM, tumor cells secrete cytokines and exosomes to adjust the immune microenvironment of the liver, thus forming an inhibitory immune microenvironment for colonization by circulating tumor cells. This indicates that the immune state of patients with CC plays a crucial role in the occurrence and progression of LM.

AIM

To observe and analyze the relationship between immune status and expression of tumor factors in patients with LM of CC, and to provide a scientific intervention method for promoting the patient prognosis.

METHODS

A retrospective analysis was performed. The baseline data of 100 patients with CC and 100 patients with CC who suffered from postoperative LM and were admitted to our hospital from May 2021 to May 2023 were included in the non-occurrence and occurrence groups, respectively. The immune status of the patients and the expression of tumor factor-related indicators in the two groups were compared, and the predictive value of the indicators for postoperative LM in patients with CC was analyzed.

RESULTS

Compared with the non-occurrence group, the expression of serum carcinoembryonic antigen (CEA), CA19-9, CA242, CA72-4 and CA50 in patients in the occurrence group were significantly higher, while the expression of CD3+, CD4+, CD8+, natural killer (NK) and CD4+/CD25 in patients in the occurrence group were significantly lower (P < 0.05). No significant difference was observed in other baseline data between groups (P > 0.05). Multivariate logistic regression model analysis revealed that the expressions of CEA, CA19-9, CA242, CA72-4, CA50, CD3+, CD4+, CD8+, NK, and CD4+/CD25 were associated with the LM in patients with CC. High expressions of serum CEA, CA19-9, CA242, CA72-4 and CA50, and low expressions of CD3+, CD4+, CD8+, NK, and CD4+/CD25 in patients with CC were risk factors for LM (OR > 1, P < 0.05). The receiver operating characteristic curve showed that the area under curve for CEA, CA19-9, CA242, CA72-4, CA50, CD3+, CD4+, CD8+, NK, and CD4+/CD25 in the prediction of LM in patients with CC were all > 0.80, with a high predictive value.

CONCLUSION

The expression of tumor factors and immune state-related indices in patients with CC is closely associated with the occurrence of LM.

Towards targeted colorectal cancer biopsy based on tissue morphology assessment by compression optical coherence elastography

Identifying the precise topography of cancer for targeted biopsy in colonoscopic examination is a challenge in current diagnostic practice. For the first time we demonstrate the use of compression optical coherence elastography (C-OCE) technology as a new functional OCT modality for differentiating between cancerous and non-cancerous tissues in colon and detecting their morphological features on the basis of measurement of tissue elastic properties. The method uses pre-determined stiffness values (Young’s modulus) to distinguish between different morphological structures of normal (mucosa and submucosa), benign tumor (adenoma) and malignant tumor tissue (including cancer cells, gland-like structures, cribriform gland-like structures, stromal fibers, extracellular mucin). After analyzing in excess of fifty tissue samples, a threshold stiffness value of 520 kPa was suggested above which areas of colorectal cancer were detected invariably. A high Pearson correlation (r =0.98; p &lt;0.05), and a negligible bias (0.22) by good agreement of the segmentation results of C-OCE and histological (reference standard) images was demonstrated, indicating the efficiency of C-OCE to identify the precise localization of colorectal cancer and the possibility to perform targeted biopsy. Furthermore, we demonstrated the ability of C-OCE to differentiate morphological subtypes of colorectal cancer – low-grade and high-grade colorectal adenocarcinomas, mucinous adenocarcinoma, and cribriform patterns. The obtained ex vivo results highlight prospects of C-OCE for high-level colon malignancy detection. The future endoscopic use of C-OCE will allow targeted biopsy sampling and simultaneous rapid analysis of the heterogeneous morphology of colon tumors.

Putative anoikis resistant subpopulations are enriched in lymph node metastases and indicate adverse prognosis in colorectal carcinoma

Anoikis refers to apoptosis induced by the loss of contact with the extracellular matrix. Anoikis resistance is essential for metastasis. We have recently shown that it is possible to quantitatively evaluate putative anoikis resistant (AR) subpopulations in colorectal carcinoma (CRC). Abundance of these multi-cell structures is an independent marker of adverse prognosis. Here, we have quantified putative AR subpopulations in lymph node (LN) metastases of CRC and evaluated their prognostic value and relationship with the characteristics of primary tumors. A case series included 137 unselected CRC patients, 54 with LN metastases. Areal densities (structures/mm²) of putative AR structures in primary tumors had been analyzed previously and now were determined from all nodal metastases (n = 183). Areal density of putative AR structures was higher in LN metastases than in primary tumors. Variation of the areal density within different LN metastases of a single patient was lower than between metastases of different patients. Abundance of putative AR structures in LN metastases was associated with shorter cancer specific survival (p = 0.013), and this association was independent of T and N stages. Abundance of putative AR structures in primary tumors and LN metastases had a cumulative adverse effect on prognosis. Enrichment of putative AR subpopulations in LN metastases suggest that in metastasis formation, there is a selection favoring cells capable of forming these structures. Higher intra-case constancy relative to inter-case variation suggests that such selection is stable in metastasis development. Our findings indirectly support the biological validity of our concept of putative AR structures.