Clinicopathological features and phenotypic classification of de novo-type colorectal carcinomas differ from those of colorectal carcinomas derived from flat adenomas

Primary adenocarcinoma arising from rectal implantation cyst after low anterior resection for rectal cancer 31 years previously

Rectal implantation cysts can occur at anastomotic sites after low anterior resection (LAR) for rectal cancer. Herein, we report a case of primary adenocarcinoma arising from a rectal implantation cyst after LAR for rectal cancer. A 70-year-old woman was referred to our hospital for diagnosis and treatment of a growing cystic lesion. She had LAR performed for rectal cancer 29 years previously and had a rectal implantation cyst detected 13 years previously. On the first visit to our hospital, serum CEA and CA19-9 levels were elevated, and computed tomography (CT) scans revealed a cystic lesion near the anastomosis. CT-guided biopsy revealed no cancer tissue in the cystic lesion. After that, the cystic lesion naturally shrank, and serum CEA and CA19-9 levels became normal. Follow-up included 3 monthly serum CEA and CA19-9 testing and 6 monthly CT scans. Two years later, serum CEA and CA19-9 levels were elevated again. Colonoscopy revealed an ulcerative lesion at the anastomotic site, in which adenocarcinoma was confirmed. Abdominoperineal resection with sacral resection was performed, and postoperative histopathological examination revealed a primary adenocarcinoma with mucinous component at the implantation cyst. Since rectal implantation cysts can become malignant after extended periods, clinicians need to be aware of this disease.

Mucin phenotype and genetic alterations in non-V600E BRAF-mutated colorectal cancer

Colorectal cancer (CRC) is a heterogeneous disease that develops through stepwise accumulation of genetic alterations and progresses via several distinct pathways. However, the tumorigenesis of CRCs with BRAF non-V600E mutations remains unclear. Here, we aimed to elucidate the tumorigenesis of CRCs with BRAF non-V600E mutations, focusing on differences in mucin phenotype and genetic alterations between CRCs with non-V600E and V600E mutations. We investigated 201 patients with CRC and performed panel testing of 415 genes to identify BRAF mutations. Patients were classified into five mucin phenotypes - large-intestinal, small-intestinal, gastric, mixed, and unclassified - using immunohistochemistry for CD10, MUC2, MUC5AC, and MUC6. BRAF mutations were identified in 24 of 201 patients' samples, of which 13 (6.5%) had a V600E mutation (V600E-mutant) and 11 (5.5%) had non-V600E mutations (non-V600E-mutant). MUC5AC expression was significantly associated with V600E mutations (P = 0.040), while CD10 expression was significantly associated with non-V600E mutations (P = 0.010). The small-intestinal mucin phenotype was significantly associated with non-V600E mutations (P = 0.031), while the mixed mucin phenotype was significantly associated with V600E mutations (P = 0.027). Regarding genetic alterations, focusing on the WNT signaling pathway, APC mutation was significantly associated with non-V600E mutations (P < 0.001), while RNF43 mutation was significantly associated with V600E mutations (P = 0.020). Considering the differences in mucin phenotype and genetic alterations, different modes of tumorigenesis are assumed for CRC with BRAF V600E mutation and non-V600E mutations. These findings are important in understanding the biology and treatment strategies for BRAF-mutant CRC.

Endoscopic and pathological characteristics of de novo colorectal cancer: Retrospective cohort study

BACKGROUND

Endoscopy has rapidly developed in recent years and has enabled further investigation into the origin and features of intestinal tumors. The small size and concealed position of these tumors make it difficult to distinguish them from nonneoplastic polyps and carcinoma in adenoma (CIA). The invasive depth and metastatic potential determine the operation regimen, which in turn affects the overall survival and distant prognosis. The previous studies have confirmed the malignant features and clinicopathological features of de novo colorectal cancer (CRC).

AIM

To provide assistance for diagnosis and treatment, but the lack of a summary of endoscopic features and assessment of risk factors that differ from the CIA prompted us to conduct this retrospective study.

METHODS

In total, 167 patients with small-sized CRCs diagnosed by endoscopy were reviewed. The patients diagnosed as advanced CRCs and other malignant cancers or chronic diseases that could affect distant outcomes were excluded. After screening, 63 cases were excluded, including 33 de novo and 30 CIA cases. Patient information, including their follow-up information, was obtained from an electronic His-system. The characteristics between two group and risk factors for invasion depth were analyzed with SPSS 25.0 software.

RESULTS

Nearly half of the de novo CRCs were smaller than 1 cm (n = 16, 48.5%) and the majority were located in the distal colon (n = 26, 78.8%). The IIc type was the most common macroscopic type of de novo CRC. In a Pearson analysis, the differential degree, Sano, JNET, and Kudo types, surrounding mucosa, and chicken skin mucosa (CSM) were correlated with the invasion depth (P < 0.001). CSM was a significant risk factor for deep invasion and disturbed judgment of endoscopic ultrasound. A high degree of tumor budding and tumor-infiltrating lymphocytes are accompanied by malignancy. Finally, de novo CRCs have worse outcomes than CIA CRCs.

CONCLUSION

This is the first comprehensive study to analyze the features of de novo CRCs to distinguish them from nonneoplastic polyps. It is also the first study paying attention to CSM invasive depth measurement. This study emphasizes the high metastatic potential of de novo CRCs and highlights the need for more research on this tumor type.

Quantifying the Matrix Metalloproteinase 2 (MMP2) Spatially in Tissues by Probe via MALDI Imaging Mass Spectrometry

As a matrix metalloproteinase, the abnormal expression of MMP2 is associated with multiple biological processes, including tissue remodeling and cancer progression. Therefore, spatial analysis of MMP2 protein in tissues can be used as an important approach to evaluate the expression distribution of MMP2 in complex tissue environments, which will help the diagnosis and treatment of various diseases, including tissue or organ injuries. Moreover, this analysis will also help the evaluation of prognoses. However, MMP2 is difficult to be spatially determined by MALDI TOF mass spectrometry due to its large molecular weight (over 72 KD) and low content. Therefore, a new method should be developed to help this detection. Here, we have designed a specific MMP2 probe that closely binds to MMP2 protein in tissue. This probe has a Cl on Tyr at the terminal, which can provide two isotope peaks to help the accuracy quantitative of MMP2 protein. Based on this, we used the probe to determine the spatial expression of MMP2 in the tissues based on MALDI TOF mass spectrometry. This approach may help to study the influence of multifunctional proteases on the degree of malignancy in vivo.

Vascular endothelial growth factor-A is an Immunohistochemical biomarker for the efficacy of bevacizumab-containing chemotherapy for duodenal and jejunal adenocarcinoma

BACKGROUND

The efficacy and safety of bevacizumab-containing chemotherapy for patients with metastatic duodenal and jejunal adenocarcinoma (mDJA) are unclear. The present study aimed to evaluate the efficacy of bevacizumab and to explore immunohistochemical markers that can predict the efficacy of bevacizumab for patients with mDJA.

METHODS

This multicentre study included patients with histologically confirmed small bowel adenocarcinoma who received palliative chemotherapy from 2008 to 2017 at 15 hospitals. Immunostaining was performed for vascular endothelial growth factor-A (VEGF-A), TP53, Ki67, β-catenin, CD10, MUC2, MUC5AC, MUC6, and mismatch repair proteins.

RESULTS

A total of 74 patients were enrolled, including 65 patients with mDJA and 9 with metastatic ileal adenocarcinoma. Patients with mDJA who received platinum-based chemotherapy with bevacizumab as first-line treatment tended to have a longer progression-free survival and overall survival than those treated without bevacizumab (P = 0.075 and 0.077, respectively). Multivariate analysis extracted high VEGF-A expression as a factor prolonging progression-free survival (hazard ratio: 0.52, 95% confidence interval: 0.30-0.91). In mDJA patients with high VEGF-A expression, those who received platinum-based chemotherapy with bevacizumab as a first-line treatment had significantly longer progression-free survival and tended to have longer overall survival than those treated without bevacizumab (P = 0.025 and P = 0.056, respectively), whereas no differences were observed in mDJA patients with low VEGF-A expression.

CONCLUSION

Immunohistochemical expression of VEGF-A is a potentially useful biomarker for predicting the efficacy of bevacizumab-containing chemotherapy for patients with mDJA.

Endometrial endometrioid carcinoma, grade 1, is more aggressive in the elderly than in the young

AIMS

The aim of this study was to characterise grade 1 (G1) endometrioid carcinoma in the elderly, by using clinicopathological features and immunohistochemical features of surrogate markers of molecular subtypes.

METHODS AND RESULTS

We retrospectively analysed tumour samples from 268 patients with G1 endometrioid carcinoma (<40 years, n = 24; 40-59 years, n = 169; ≥60 years, n = 75) for whom long-term clinical follow-up data were available. G1 endometrioid carcinoma in the elderly (≥60 years) was characterised by frequent deep myometrial invasion, less frequent endometrioid intraepithelial neoplasia (EIN), lack of benign hyperplasia (BH), less frequent squamous differentiation, and occasional aberrant p53 expression. In contrast, this condition in the young (<40 years) was characterised by frequent EIN, BH, and squamous differentiation. Univariate analysis revealed that elderly status (≥60 years), International Federation of Obstetrics and Gynecology (FIGO) 2009 stage and aberrant p53 expression were significantly associated with shorter progression-free survival, and multivariate analysis revealed that elderly status and FIGO 2009 stage were independently associated with a poor prognosis.

CONCLUSIONS

G1 endometrioid carcinoma in the elderly is more aggressive than that in the young, and elderly status is an independent predictor of shorter progression-free survival in this condition. We propose that type 1 tumours can be subdivided into type 1a (young age at onset and indolent) and type 1b (old age at onset and relatively aggressive).