Conventional Colorectal Adenocarcinoma Research Articles

Clinicopathological features of rectal adenocarcinoma with enteroblastic differentiation

Objective: To investigate the clinicopathological features, immunophenotype, and genetic alterations of rectal adenocarcinoma with enteroblastic differentiation. Methods: Four cases of rectal adenocarcinoma with enteroblastic differentiation were collected at the Affiliated Hospital of Qingdao University, Qingdao, China (three cases) and Yantai Yeda Hospital of Shandong Province, China (one case) from January to December 2022. Their clinical features were summarized. Hematoxylin and eosin stain and immunohistochemical stain were performed, while next-generation sequencing was performed to reveal the genetic alterations of these cases. Results: All four patients were male with a median age of 65.5 years. The clinical manifestations were changes of stool characteristics, bloody stools and weight loss. All cases showed mixed morphology composed of conventional adenocarcinoma and adenocarcinoma with enteroblastic differentiation. Most of the tumors consisted of glands with tubular and cribriform features. In one case, almost all tumor cells were arranged in papillary structures. The tumor cells with enteroblastic differentiation were columnar, with relatively distinct cell boundaries and characteristic abundant clear cytoplasm, forming fetal gut-like glands. Immunohistochemically, the tumor cells were positive for SALL4 (4/4), Glypican-3 (3/4) and AFP (1/4, focally positive), while p53 stain showed mutated type in 2 cases. The next-generation sequencing revealed that 2 cases had TP53 gene mutation and 1 case had KRAS gene mutation. Conclusions: Rectal adenocarcinoma with enteroblastic differentiation is rare. It shows embryonal differentiation in morphology and immunohistochemistry, and should be distinguished from conventional colorectal adenocarcinoma.

Colorectal adenosquamous carcinoma: genomic profiling of a rare histotype of colorectal cancer

Colorectal adenosquamous carcinoma (ASC) is exceedingly rare, comprising less than 0.1% of all colorectal malignancies, and is characterized by an aggressive disease course, with a higher metastatic rate and worse outcome than conventional colorectal adenocarcinoma. A comprehensive molecular profile of this group of neoplasms is still lacking. A total of 22 cases of colorectal ASCs (with 22 primary lesions and 7 metastases matched with 4 primaries) were subject to NGS targeting 67 cancer-related genes (VariantPlex solid tumor; Archer). Mismatch repair (MMR), p53, and V600EBRAF status were also investigated by immunohistochemistry. In 28 of 29 (96.6%) ASC samples, at least one single-nucleotide variant (SNV) or copy number variation (CNV) was detected. Among the 22 primary tumors, the most frequently mutated genes were TP53 (59.1%), APC (40.9%), KRAS (27.3%), BRAF (13.6%), and GNAS (9.1%). Only 1/22 (4.5%) primary ASC was MMR-deficient (MMRd) and harbored a BRAF mutation. Limited differences in SNVs were observed between primary and metastatic diseases. This study sheds light on the molecular landscape of colorectal ASCs. According to our data, the genomic profile of colorectal ASC is similar to that of conventional colorectal carcinoma, with significant druggable genetic alterations. Further studies are required to understand the more aggressive clinical behavior of this neoplasm.

Evaluation of the significance of human class I homeobox A13 and STK4/MST1 expression in conventional colorectal adenoma and adenocarcinoma and correlation with clinicopathological parameters (immunohistochemical study)

Background Colorectal carcinoma (CRC) is the third most common cancer in the world. Human class I homeobox A13 (HOXA13) was initially identified as a transcription factor and has an important role in embryonic development and malignant transformation. Mammalian STE20-like kinase 1 (STK4/MST1) encodes a serine/threonine kinase that is the mammalian homolog of the Hippo pathway and plays an important role in controlling cell growth, apoptosis, and organ size. Aim This work aimed to evaluate the role of HOXA13 and STK4/MST1 in conventional colorectal adenoma and adenocarcinoma. Materials and methods This retrospective study was carried out on 20 cases of conventional colorectal adenoma and 30 cases of conventional colorectal adenocarcinoma. HOXA13 and STK4/MST1 immunostaining was done and assessed for each case. Correlation with the clinicopathological findings and statistical analysis was studied. Results In the carcinoma cases, there was a highly significant direct statistical correlation between HOXA13 expression and tumor grade, lymph node metastasis, and TNM stage (P<0.01 for each). Inverse statistical correlation between STK4/MST1 expression and tumor grade, depth of tumor invasion (T), and TNM stage (P<0.01 for each) was found. HOXA13 and STK4/MST1 immunoexpression showed direct highly significant relation with the transition from adenoma to adenoma with dysplasia to adenocarcinoma (P<0.01). There was a highly significant inverse statistical correlation between HOXA13 and STK4/MST1 expression in the studied cases of CRC (P<0.01). According to receiver-operating characteristic curve, both markers were good in the prediction of metastatic potential in the carcinoma cases using the TNM stage as a parameter with a sensitivity of 85%. Conclusion HOXA13 was immunohistochemically overexpressed, while STK4/MST1 was downexpressed in progression from colorectal adenoma to adenoma with dysplasia to adenocarcinoma cases. HOXA13 and STK4/MST1 might have a potential role as independent prognostic factors in CRC and may have validity to predict metastatic potential of CRC.

Most colitis associated carcinomas lack expression of LGR5: a preliminary study with implications for unique pathways of carcinogenesis compared to sporadic colorectal carcinoma

BackgroundLeucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), a component of the Wnt receptor complex, is thought to lineage label gastric and intestinal stem cells. LGR5 expression is increased in colorectal carcinoma (CRC) compared to normal tissue. Colitis associated colorectal adenocarcinoma (CAC) often shows distinct morphologic and molecular phenotypes compared to sporadic cases. However, the expression profile of LGR5, and by extension the potential role of an intestinal stem cell phenotype, has not been well described in a series of human CAC.MethodRNA in situ hybridization (ISH) for LGR5 expression on 30 CACs (12 cases with conventional morphology and 18 cases with non-conventional type morphology) from 29 inflammatory bowel disease (IBD) patients was performed and compared the expression profile to a control group of 10 sporadic CRCs. Immunohistochemistry for beta-catenin and SATB2 was performed on the 30 CACs.ResultLGR5 was positive in 30% (9/30) of CAC cases and 90% (9/10) of sporadic CRCs (p = 0.002). A large majority (89%) of LGR5 positive CACs were of the conventional histologic type, and conventional type CAC showed a significantly higher LGR5 score (median 3.0; interquartile range 1.75–3.25) than non-conventional type CAC (median 1.5; interquartile range 1.00–2.00) (p = 0.034). CAC with conventional morphology did have a lower level of LGR5 expression than sporadic CRC. Sporadic CRCs showed a significantly higher LGR5 level score than non-conventional type CACs (p < 0.001). Nuclear translocation of beta-catenin was strongly associated with LGR5 expression (p = 0.003), however no significant association was identified between SATB2 expression and LGR5 expression status in CACs.ConclusionThese findings suggest that the wider spectrum of tumor morphology in CAC may be associated with absence of a LGR5-expressing intestinal stem cell phenotype.

CDH1 gene mutation in early-onset, colorectal signet-ring cell carcinoma

AimColorectal signet-ring cell carcinomas (SRCC) are highly malignant tumours with poor prognosis that disproportionately affect younger patients. There is growing evidence of a unique set of molecular features that separate SRCC from conventional colorectal adenocarcinoma. Identification of these distinct features may have diagnostic and prognostic significance for patients and families. CDH1, which encodes E-cadherin, a cell adhesion protein, is commonly mutated in gastric SRCC and our study aimed to identify whether CDH1 mutation was also a common phenomenon in colorectal SRCC. MethodsDNA was extracted from formalin-fixed paraffin embedded tumour tissue, the CDH1 gene was analysed by next generation sequencing and the pathogenicity of mutations assessed in silico. Sections cut from the same blocks were immunostained to identify the presence of the E-cadherin protein. ResultsWe found 8 CDH1 mutations that meet our inclusion criteria in seven of 11 samples. Of these, five (from four patients), were likely to be germline mutations. E-cadherin staining was absent or markedly reduced in all of the seven samples with CDH1 mutation. ConclusionOur finding of CDH1 mutations in a proportion of signet-ring cell carcinomas and associated reduction in E-cadherin in these tumours supports previous findings of a role for mutation of this gene in the development of this disease. In addition, the finding of likely germline mutations suggests that a subset of these tumours may be familial. Loss of E-cadherin staining in the absence of CDH1 mutations however also suggests a role for environmental factors in a subset of these tumours.

SATB1 Expression of Colorectal Adenomatous Polyps is Higher than that of Colorectal Carcinomas.

"Special AT-rich sequence-binding protein-1" (SATB1) is a global genome organizer and is found to have effects on carcinogenesis and progression of various malignancies including colorectal carcinoma (CRC). We aimed to investigate the expression of SATB1 in CRC and colorectal adenomatous polyps (CAP), the correlation between clinicopathologic parameters, and overall survival. We examined 227 CRCs and 129 CAPs. SATB1 protein expression was evaluated by immunohistochemistry. We found higher SATB1 expression in adenomatous epithelium than in CRC tissues (55.0% vs. 42.7%, respectively) (P<0.05). None of the adjacent normal colorectal mucosa stained positive in CRC cases, and only one of the adjacent normal mucosa of the CAP cases was positive. SATB1 expression of left-sided CRC was higher than that of right-sided CRC (46.3% vs. 28.6%, respectively) (P<0.05), and SATB1 expression of conventional adenocarcinomas was higher than that of mucinous carcinomas (45.5% vs. 6.3%, respectively) (P<0.05). SATB1 expression was higher in CAPs consisting of high-grade dysplasia than in polyps with low-grade dysplasia (77.8% vs. 51.4%) (P<0.05). SATB1 expression did not correlate with patients' overall survival. In conclusion, due to the higher expression of SATB1 in CAP than in CRC, we think SATB1 may have a role in the early stages of carcinogenesis of CRCs. This is the first study investigating SATB1 expression in CAPs. Besides this is the first report that shows different SATB1 expressions in conventional colorectal adenocarcinoma and mucinous carcinoma, and also in right-sided and left-sided CRC. Our results, with supporting new studies, can provide SATB1 as a possible candidate for targeted therapy for CRC patients.

Targeting Differentially Expressed UPR Mediators in Mucin‐rich Colorectal Cancers and Conventional Colorectal Adenocarcinomas

BackgroundDespite the improved 5‐year survival rate, colorectal cancer (CRC) is the second leading cause of cancer deaths in the United States and is sub‐classified according to mucin content as mucin‐rich CRC (MCRC, ≥50% mucin content) or conventional colorectal adenocarcinoma (CCRA, &lt;50% mucin content). Ten percent of CRCs are considered mucin‐rich and are reported to be less sensitive to chemotherapy treatment than CCRAs. The unfolded protein response (UPR) is an adaptive response activated when unfolded proteins accumulate in the endoplasmic reticulum (ER). When the UPR is incapable of dealing with an increased protein load, it leads to apoptosis. Despite the increased protein load and UPR activation, tumor cells are known to maintain protein homeostasis and avoid apoptosis.ObjectivesWe hypothesized that the higher protein load in MCRC cells, initiated by the high demand of producing mucins, induces greater ER stress and activation of the UPR. Here, we aimed to identify UPR markers uniquely upregulated in their expression in MCRC versus CCRA patient biopsies. We also utilized CRC cell lines with similar mucin and UPR profiles as the biopsies, to target differentially regulated UPR markers for inhibition as potential targets for CRC therapy.ResultsOur data showed that when compared to CCRA samples, MCRC biopsies express significantly higher mRNAs for several UPR markers such as IRE1α, XBP1, and CHOP, which significantly correlate (p&lt;0.0001, p&lt;0.0001, p=0.0003, respectively) with MUC6 expression. In contrast, CCRA samples expressed higher levels of several protein disulfide isomerases (PDIs) including PDIA1 (p=0.0001), PDIA3 (p&lt;0.0001), PDIA5 (p&lt;0.0001), and PDIA17 (p=0.0025), that are known to be the downstream of canonical transducers of the UPR. We also identified CCRA (Caco2) and MCRC (LS174T) cell lines with similar UPR profiles to the biopsies. Our data indicate that cells from the MCRC cell line were less responsive to LOC14, a PDI inhibitor, whereas the CCRA cell line, which expressed higher levels of several PDIs, were less proliferative and had a greater decrease in total cell numbers following 6 days of treatment with LOC14. Accordingly, treatment with LOC14 inhibited one of the PDIs, PDIA3 in the CCRA cell, but not the MCRC cell line.ConclusionsThese novel results suggest that CCRAs and MCRCs have different signatures of UPR markers and CCRAs may be more responsive to PDI inhibitors of the UPR than MCRCs. Further characterization of the UPR profiles of CCRAs and MCRCs could aid in the development of future anti‐cancer therapies and targeting of UPR transducers and their downstream mediators.Support or Funding InformationNIH R01 HL122383 and Department of Pathology and Laboratory Medicine (UVM) Startup Fund (VA)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Invasive micropapillary component and its clinico-histopathological significance in patients with colorectal cancer.

Micropapillary components are located in distinct, empty spaces resembling lymphatic vessels and consist of clusters of cancer cells that adhere tightly to one another. These structures do not have a fibrovascular core. Invasive micropapillary components (IMPCs) exhibit reverse polarity, which results in a characteristic 'inside-out' structure. The aim of the present study was to examine the histological significance of the micropapillary component in colorectal carcinoma compared with conventional colorectal adenocarcinoma. Among 115 patients, 5 (4.3%) were diagnosed with a micropapillary colorectal component based on hematoxylin and eosin staining and immunohistochemical analysis. To exclude identification of poorly-differentiated clusters of adenocarcinoma cells in the lymphatic vessels, immunohistochemical analysis with D2-40 was performed, and epithelial membrane antigen was used to confirm the specific 'inside-out' structure of IMPCs. IMPCs were observed to positively correlate with histopathological type (P=0.001) and tumor invasion in venous vessels (P=0.033). Furthermore, the presence and number of lymph node metastases was greater in IMPC cases compared with conventional carcinoma cases; however, these differences were not statistically significant (P=0.087 and P=0.094, respectively). In addition, IMPC cases were not significantly associated with the presence of inflammatory infiltrate in the invasive front of the tumor (P=0.098). Therefore, the present study indicates that the IMPC serves a histopathological and prognostic role in the diagnosis of colorectal cancer due to its aggressive and invasive behavior. IMPC is rare in cases of colorectal cancer and remains a great diagnostic challenge in pathomorphology with further detailed investigation required in the future.

EGFR, KRAS, BRAF-mutations and microsatellite instability are absent in goblet cell carcinoids of the appendix

Goblet cell carcinoid (GCC) is a rare type of mixed endocrine–exocrine tumor of the appendix often showing a clinically aggressive behavior. On a molecular basis, this tumor is only poorly understood. To analyze possible molecular similarities between GCC and colorectal cancer, we examined 14 cases of GCC for mutations in exons 18, 19 and 21 of the EGFR-gene, exon 2 in the KRAS gene and for V600E mutations of the BRAF gene. Although the sensitive pyrosequencing method was used, no EGFR, KRAS or BRAF mutations could be found. Furthermore, using immunohistochemistry, no evidence for microsatellite instabillity (MSI) could be found. Despite the partial intestinal differentiation of GCC, our study indicates that the molecular pathogenesis of GCC significantly differs from conventional colorectal adenocarcinoma. This finding might also have implications in adjuvant chemotherapeutic treatment of advanced GCC.

Relationship between colorectal adenocarcinoma with invasive micropapillary carcinoma component and lymph node metastasis

To investigate the relationship between colorectal adenocarcinoma with invasive micropapillary carcinoma (IMPC) component, lymphovascular invasion, and lymph node metastasis. One hundred and thirty one cases of colorectal adenocarcinoma with invasive micropapillary carcinoma component were evaluated by H&E and immunohistochemical staining. The main pathological features, percentage of IMPC component, lymphovascular invasion, and lymph node metastasis were assessed and compared to 296 cases of conventional colorectal adenocarcinoma. The maximum diameter of the tumors of the IMPC group was significantly lower than the conventional group. The degree of differentiation, the lymph node metastatic rate, the average number of metastatic lymph nodes, the number of cases with lymphovascular tumor emboli were significantly higher in the IMPC group (P = 0.000). The rate of distant metastasis at operation was higher in the IMPC group (14.5%) compared to the conventional group (10.8%) even though statistical significance was not achieved (P = 0.278) . In IMPC group, as the IMPC component increased, the rate of lymph node metastasis also showed an increasing trend. The rate of lymph node metastasis were 53.0% (157/296) , 67.7% (42/62) and 85.5% (59/69) " respectively" for conventional adenocarcinoma, adenocarcinoma with ≤ 10% IMPC component and adenocarcinoma with > 10% IMPC component; the difference was statistically significant (P = 0.000). Compared to conventional colorectal adenocarcinomas, the colorectal carcinomas with IMPC component show a significantly higher rate of lymphovascular invasion, lymph node metastasis and distant metastasis. The percentage of IMPC component in colorectal adenocarcinoma is significantly correlated to the rate of lymph node metastasis. Therefore, presence of IMPC component and degree of tumor differentiation are predicting factors of lymph node metastasis.

Clinicopathological and molecular characterization of colorectal micropapillary carcinoma

Invasive micropapillary carcinoma is associated with frequent lymph node metastasis and adverse clinical outcome. Initially described as a variant of breast and ovarian carcinoma, it has subsequently been found in other organs, most recently the colon. Reports of colorectal micropapillary carcinoma to date are limited in number, and their molecular profile has not been established. The aims of the present study were to analyze their clinicopathological features and molecular profile, and compare them with those of conventional adenocarcinoma. Clinicopathological features of a cohort of 379 patients with primary colorectal cancer were retrospectively reviewed for the presence of the pattern characteristic of micropapillary carcinoma. We also assessed the expression of KRT7, KRT20, CEACAM5, MUC1 (EMA, clone E29), MUC1 (clone MA695), MLH1, MSH2, MSH6 and TP53 by immunohistochemistry. Genetic assessments of microsatellite instability, chromosomes 17p and 18q, and mutations in TP53, BRAF and KRAS were performed using DNA extracted from formalin-fixed, paraffin-embedded sections. In all, 60 of the reviewed cases (16%) had a micropapillary component that ranged from 5 to 95% of the tumor, characterized by a higher frequency of an infiltrative pattern, lymphovascular and perineural invasion, a higher depth of invasion and more positive lymph nodes than conventional adenocarcinoma. Immunohistochemistry for MUC1 (clone MA695) and MUC1 (EMA, clone E29) enhanced the characteristic inside–out staining pattern of the micropapillary carcinoma component, whereas the rest of the tumor showed luminal staining patterns. KRT7 expression was slightly increased in micropapillary carcinoma, but did not reach significance (17–3%, P=0.1967). The molecular parameters showed a higher frequency of TP53 alterations and a low incidence of microsatellite instability and RER phenotype (loss of mismatch repair protein) in micropapillary carcinoma. With regard to the histological parameters, micropapillary carcinoma appears to be more aggressive than conventional colorectal adenocarcinoma. The molecular profile supports the hypothesis that micropapillary carcinoma carcinogenesis develops through the classical chromosomal instability pathway.

Signet-ring cell carcinoma of colorectum—current perspectives and molecular biology

Colorectal signet-ring cell carcinoma (SRCC) is rare, and very little detailed information on the molecular biology of the disease is available. The literature on the clinical, pathological and, in particular, the molecular biology of this rare entity was critically reviewed. The reviewed articles take into account a total of 1,817 cases of SRCC, but only 143 cases have molecular data available. The characteristics of two patients with colorectal SRCC were also discussed. Colorectal SRCC mostly occurs in younger patients, is larger and has different site predilection compared with conventional colorectal adenocarcinoma. It can occur as one of the synchronous cancers in the colorectum. The cancer is usually diagnosed at advanced stages because of the late manifestation of symptoms, and aggressive treatment strategy is required. Limited reports in the literature have shown that the variant of colorectal cancer demonstrated a different pattern of genetic alterations of common growth kinase-related oncogenes (K-ras, BRAF), tumour suppressor genes (p53, p16), gene methylation and cell adhesion-related genes related to the Wingless signalling pathway (E-cadherin and beta-catenin) from conventional colorectal adenocarcinoma. Colorectal SRCC also showed high expression of mucin-related genes and genes related to the gastrointestinal system. There was also a higher prevalence of microsatellite instability-high tumours and low Cox-2 expression in colorectal SRCC as opposed to conventional adenocarcinoma. Colorectal SRCC has unique molecular pathological features. The unique molecular profiles in SRCC may provide molecular-based improvements to patient management in colorectal SRCC.

Altered expression of MUC2 and MUC5AC in progression of colorectal carcinoma

To study the expression profiles of MUC2 and MUC5AC in tumorigenesis of colorectal carcinoma and in its different pathologic types. Formalin-fixed, paraffin-embedded human colorectal tissue specimens were immunostained with antibodies against MUC2 and MUC5AC. Six samples of normal mucosa (NM), 12 samples of hyperplastic polyp (HP), 15 samples of tubular adenoma with low-grade dysplasia (LGD), 14 samples of tubular adenoma with high-grade dysplasia (HGD), 26 samples of conventional colorectal adenocarcinoma (CCA), 15 samples of mucinous carcinoma (MC), and 8 samples of signet-ring cell carcinoma (SRCC) were collected. MUC2 was the most widely expressed protein in each study group, although the number of MUC2-positive cases was less in CCA group than in other groups (P < 0.05). The staining score for MUC2 was significantly decreased in the HP-LGD-HGD-CCA sequence (r = -0.73436, P < 0.0001). Among the neoplasms, MC and SRCC were more frequently associated with the high expression of MUC2 (P < 0.05) than with that of CCA. MUC5AC expression was detected in all groups but not in NM group. Furthermore, the staining score for MUC5AC was higher in HP, LGD, HGD, MC and SRCC groups than in NM and CCA groups (P < 0.05). The frequency of simultaneous expression of MUC proteins was significantly higher in MC and SRCC groups than in CCA group (P < 0.05). Alterations in MUC expression occur during colorectal tumorigenesis. The transformation process in MC and SRCC may be different from that in the traditional adenoma-carcinoma sequence.

Colorectal adenocarcinoma with micropapillary pattern and its association with lymph node metastasis

Micropapillary carcinoma has been reported as an aggressive variant of carcinoma in several organs, where it is associated with frequent lymphovascular invasion and poor clinical outcome. This study explored the clinicopathological features of colorectal adenocarcinoma with a micropapillary carcinoma component and compared them with those of conventional colorectal adenocarcinoma. One hundred seventy-eight consecutive cases of surgically resected colorectal carcinomas were studied for tumor size, type, depth of invasion, nodal and distant metastases, tumor stage, and percentage and extent of micropapillary component. Among 178 cases of colorectal carcinoma, 34 (19.1%) cases had a micropapillary component, which ranged from 5 to 60% of the entire tumor. Lymph node metastasis was identified in 25 of 34 (73.5%) carcinomas with micropapillary component, whereas they were detected in 61 of 144 (42.4%) cases without micropapillary component (P=0.001). Lymphovascular invasion was identified more frequently in carcinoma with micropapillary component (41.2%) than carcinoma without micropapillary component (20.1%; P<0.05). Distant metastases occurred in 4 of 34 cases (11.7%) with micropapillary component and in 10 of 144 cases (6.9%) without micropapillary component (P=0.311). Multivariate regression analysis demonstrated that the presence of micropapillary component, as well as tumor stage and lymphovascular invasion are independent predictors of regional nodal metastasis.