Is neuroendocrine differentiation a prognostic factor in poorly differentiated colorectal cancer?

High expression of insulinoma-associated protein 1 (INSM1) distinguishes colorectal mixed and pure neuroendocrine carcinomas from conventional adenocarcinomas with diffuse expression of synaptophysin

Complementary to synaptophysin and chromogranin A, insulinoma-associated protein 1 (INSM1) has emerged as a sensitive marker for the diagnosis of neuroendocrine neoplasms. Since there are no comparative data regarding INSM1 expression in conventional colorectal adenocarcinomas (CRCs) and colorectal mixed adenoneuroendocrine carcinomas/neuroendocrine carcinomas (MANECs/NECs), we examined INSM1 in a large cohort of conventional CRCs and MANECs/NECs. In conventional CRC, we put a special focus on conventional CRC with diffuse expression of synaptophysin, which carry the risk of being misinterpreted as a MANEC or a NEC. We investigated INSM1 according to the immunoreactive score in our main cohort of 1,033 conventional CRCs and 21 MANECs/NECs in comparison to the expression of synaptophysin and chromogranin A and correlated the results with clinicopathological parameters and patient survival. All MANECs/NECs expressed INSM1, usually showing high or moderate expression (57% high, 34% moderate, and 9% low), which distinguished them from conventional CRCs, which were usually INSM1 negative or low, even if they diffusely expressed synaptophysin. High expression of INSM1 was not observed in conventional CRCs. Chromogranin A was negative/low in most conventional CRCs (99%), but also in most MANECs/NECs (66%). Comparable results were observed in our independent validation cohorts of conventional CRC (n = 274) and MANEC/NEC (n = 19). Similar to synaptophysin, INSM1 expression had no prognostic relevance in conventional CRCs, while true MANEC/NEC showed a highly impaired survival in univariate and multivariate analyses (e.g. disease-specific survival: p < 0.001). MANECs/NECs are a highly aggressive variant of colorectal cancer, which must be reliably identified. High expression of INSM1 distinguishes MANEC/NEC from conventional CRCs with diffuse expression of the standard neuroendocrine marker synaptophysin, which do not share the same dismal prognosis. Therefore, high INSM1 expression is a highly specific/sensitive marker that is supportive for the diagnosis of true colorectal MANEC/NEC.

Neuroendocrine differentiation: a risk fellow in colorectal cancer

BACKGROUND

Neuroendocrine differentiation (NED) is often found in colorectal cancer (CRC) and may have unique biological behavior, which has not been previously delineated. Here, we explore the relationship between CRC, NED, and clinicopathological factors. We also offer a preliminary explanation of the mechanism underlying the malignant biological behavior of NED in CRC.

METHODS

Between 2013 and 2015, 394 CRC patients who underwent radical operations were selected for analysis. The relationship between NED and clinicopathological factors was analyzed. To further clarify the pivotal role of NED in CRC, we performed bioinformatic analyses and identified genes that may be involved in NED, which were obtained from in silico data from The Cancer Genome Atlas (TCGA) database. Then, we conducted functional enrichment analyses and confirmed the critical pathways for intensive study. Moreover, we detected the expression of key proteins by immunohistochemistry and analyzed the correlation of their expression with NED.

RESULTS

The statistical analysis showed that CRC with NED was positively correlated with lymph node metastasis. Through bioinformatic analysis, we found that chromogranin A (CgA) was positively correlated with invasion and lymph node metastasis. ErbB2 and PIK3R1, which are key proteins in the PI3K-Akt signaling pathway, were closely related to NED. Furthermore, we determined that the PI3K-Akt signaling pathway likely plays a critical role in the NED of CRC.

CONCLUSIONS

CRC with NED is associated with lymph node metastasis. The PI3K-Akt signaling pathway, which is closely related to CRC, may be the mechanism promoting the malignant biological behavior of CRC with NED.

Exosome-derived lnc-HOXB8-1:2 induces tumor-associated macrophage infiltration to promote neuroendocrine differentiated colorectal cancer progression by sponging hsa-miR-6825-5p

Introduction

Neuroendocrine differentiation (NED) in colorectal cancer (CRC) cells has been known for decades, and our previous meta-analysis indicated that CRC patients with neuroendocrine differentiation have a lower 5-year survival rate. In recent years, an increasing number of studies have found that exosome-derived long non-coding RNAs (lncRNAs) play important roles in cancer progression and metastasis. However, the functions and mechanism of exosome-derived lncRNAs in CRC with neuroendocrine differentiation are not yet fully clear.

Materials and methods

The clinical significance of NED was assessed in a retrospective study of 105 patients. Next-generation sequencing and bioinformatics analysis were conducted to select lnc-HOXB8-1:2 for further study. Using immunohistochemistry, qRT–PCR, western blot, transwell assay, immunofluorescence assay, fluorescence in situ hybridization assay and dual-luciferase reporter assay, the oncogenic role of exosome-derived lnc-HOXB8-1:2 was determined in CRC with NED. The mechanism underlying the lnc-HOXB8-1:2/hsa-miR-6825-5p/CXCR3 axis was also explored.

Results

NED was a risk factor for the progression and mortality of CRC. lnc-HOXB8-1:2, derived from exosomes secreted by neuroendocrine differentiated colon cancer cells, was identified in our study. The proportion of M2 macrophages and the migration and invasion capacities of tumor-associated macrophages (TAMs) markedly increased after the addition of neuroendocrine differentiated CRC cell-derived exosomes. More excitingly, the expression of lnc-HOXB8-1:2 and the protein level of CXCR3 were also upregulated in TAMs. The lnc-HOXB8-1:2/hsa-miR-6825-5p/CXCR3 axis was predicted via miRanda software and confirmed by the dual-luciferase reporter assay. Furthermore, the increased expression of lnc-HOXB8-1:2 was accompanied by downregulation of hsa-miR-6825-5p expression and upregulation of CXCR3 protein levels. Overexpression of hsa-miR-6825-5p also reduced CXCR3 expression.

Conclusion

lnc-HOXB8-1:2 in exosomes derived from neuroendocrine differentiated CRC cells acted as a ceRNA competitively binding hsa-miR-6825-5p to upregulate CXCR3 expression and leading to TAM infiltration and M2 polarization, which promotes neuroendocrine differentiated CRC progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09926-1.

Prognostic Value of Immunohistochemical Markers for Locally Advanced Rectal Cancer

The aim of this study is to reveal the potential roles of apoptosis markers (Bcl2 and p53), proliferation markers (Ki-67 and CyclD1), and the neuroendocrine marker Chromogranin A as markers for the radioresistance of rectal cancer. Statistically significant differences were found in the expression of p53, Ki-67, and Chromogranin A in groups of patients with and without a favorable prognosis after radiotherapy. The survival analysis revealed that the marker of neuroendocrine differentiation, Chromogranin A, also demonstrated a high prognostic significance, indicating a poor prognosis. Markers of proliferation and apoptosis had no prognostic value for patients who received preoperative radiotherapy. Higher Chromogranin A values were predictors of poor prognosis. The results obtained from studying the Chromogranin A expression suggest that the secretion of biologically active substances by neuroendocrine cells causes an increase in tumor aggressiveness.

The Expression of Chromogranin A, Syanptophysin and Ki67 in Detecting Neuroendocrine Neoplasma at High Grade Colorectal Adenocarcinoma

BACKGROUND: Neuroendocrine neoplasm (NEN) is an epithelial cell neoplasm that can give a histopathological appearance resembling high-grade colorectal adenocarcinoma. Immunohistochemical assays with specific neuroendocrine markers of chromogranin A and synaptophysin are required to establish a definite diagnosis of NEN. AIM: This study aimed to determine whether there was an expression of chromogranin A, synaptophysin and Ki67 which indicated the presence of neuroendocrine neoplasms in samples that have been diagnosed as high-grade colorectal adenocarcinoma. MATERIALS AND METHODS: A study of the expression of chromogranin A, synaptophysin and Ki67 in paraffin blocks was carried out as a result of biopsy and tissue surgery of 70 samples of colorectal tumor specimens diagnosed with colorectal adenocarcinoma. Descriptive analyses were used to assess the study results of the amount of chromogranin A, synaptophysin, and sample characteristics. RESULTS: We discovered that eight (8) samples (11.4%) were NEN from 70 previously diagnosed samples as high-grade colorectal adenocarcinoma using immunohistochemical assay with neuroendocrine markers, namely chromogranin A and synaptophysin. CONCLUSION: The final diagnosis obtained from 8 samples diagnosed as NEN were Neuroendocrine tumor (NET) G1, G2, and G3, respectively 1.4% and LCNEC 7.1% based on the specific neuroendocrine markers of chromogranin A, synaptophysin and Ki67.

Neuroendocrine Differentiation in Conventional Colorectal Adenocarcinomas: Incidental Finding or Prognostic Biomarker?

Simple Summary

Colorectal MANECs are highly aggressive carcinomas defined by a distinct neuroendocrine morphology and positivity for synaptophysin in the neuroendocrine component. It is unclear whether a neuroendocrine differentiation in conventional adenocarcinomas without a suggestive morphology is of clinical relevance. We tested 1002 conventional colorectal carcinomas with a non-neuroendocrine morphology for synaptophysin expression and correlated the results with clinicopathological characteristics as well as patient survival and compared the survival characteristics of synaptophysin expression groups to those of true MANECs. We found no survival differences between synaptophysin expression groups within conventional colorectal adenocarcinomas. MANECs, on the other hand, showed significantly worse survival characteristics. Our data suggest that synaptophysin expression in conventional colorectal adenocarcinomas is of minor prognostic relevance and that conventional adenocarcinomas with a diffuse synaptophysin expression should not be classified as MANECs.

Abstract

Background: Colorectal mixed adenoneuroendocrine carcinomas (MANECs) are clinically highly aggressive neoplasms. MANECs are composed of variable adenocarcinoma components combined with morphologically distinct neuroendocrine carcinoma components, which are confirmed by synaptophysin immunohistochemistry, the gold standard marker of a neuroendocrine differentiation. However, the biological behavior of adenocarcinomas that express synaptophysin but do not show a typical neuroendocrine morphology remains unclear. Methods: We investigated synaptophysin expression in 1002 conventional colorectal adenocarcinomas and correlated the results with clinicopathological characteristics and patient survival and compared the survival characteristics of synaptophysin expression groups to MANECs. Results: Synaptophysin expression in conventional colorectal adenocarcinomas was associated with a shortened disease-free survival (p = 0.037), but not with overall survival or disease-specific survival (DSS) in univariate analyses and without any survival impact in multivariate analyses. Patients with “true” MANECs, on the other hand, showed a significantly shorter survival than all conventional adenocarcinomas with or without synaptophysin expression in uni- and multivariate analyses (e.g., multivariate DSS: p < 0.001, HR: 5.20). Conclusions: Our study demonstrates that synaptophysin expression in conventional colorectal adenocarcinomas, in contrast to MANECs, is not associated with a significantly poorer clinical outcome when compared to adenocarcinomas without synaptophysin expression. Furthermore, our data suggest that conventional adenocarcinomas with a diffuse synaptophysin expression should not be classified as MANECs, also strongly arguing that synaptophysin testing should be reserved for carcinomas with an H&E morphology suggestive of a neuroendocrine differentiation.

Development and validation of prognostic nomograms for patients with colon neuroendocrine neoplasms

BACKGROUND

Colon neuroendocrine neoplasms (NENs) have one of the poorest median overall survival (OS) rates among all NENs. The American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) staging system-currently the most commonly used prediction model-has limited prediction accuracy because it does not include parameters such as age, sex, and treatment. The aim of this study was to construct nomograms containing various clinically important parameters to predict the prognosis of patients with colon NENs more accurately.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) database, we performed a retrospective analysis of colon NENs diagnosed from 1975 to 2016. Data were collected from 1196 patients; almost half were female (617/1196, 51.6%), and the average age was 61.94 ± 13.05 years. Based on the age triple cut-off values, there were 396 (33.1%), 408 (34.1%), and 392 (32.8%) patients in age groups 0-55 years, 55-67 years, and ≥ 68 years, respectively. Patients were randomized into training and validation cohorts (3:1). Independent prognostic factors were used for construction of nomograms to precisely predict OS and cancer-specific survival (CSS) in patients with colon NENs.

RESULTS

Multivariate analysis showed that age ≥ 68 years, sex, tumor size, grade, chemotherapy, N stage, and M stage were independent predictors of OS. In the validation cohort, the Concordance index (C-index) values of the OS and CSS nomograms were 0.8345 (95% confidence interval [CI], 0.8044-0.8646) and 0.8209 (95% CI, 0.7808-0.861), respectively. C-index also indicated superior performance of both nomograms (C-index 0.8347 for OS and 0.8668 for CSS) compared with the AJCC TNM classification (C-index 0.7159 for OS and 0.7366 for CSS).

CONCLUSIONS

We established and validated new nomograms for more precise prediction of OS and CSS in patients with colon NENs to facilitate individualized clinical decisions.

Prognostic relevance of neuroendocrine differentiation in colorectal cancer: a population-based, propensity score matching study

PURPOSE

Neuroendocrine differentiation (NED) may serve as a prognostic factor in colorectal cancer; however, the prognostic relevance of NED remains controversial. The aim of the present study was to determine whether NED influenced the survival of patients in colorectal cancer while exploring its potential interactions with other clinicopathological features.

METHODS

Patients with primary stage I to IV colorectal adenocarcinoma ranging between 2010 and 2015 were identified using the Surveillance, Epidemiology, and End Results database. The Kaplan-Meier technique, Cox proportional hazards model, propensity score matching, and stratification analyses were employed in this study.

RESULTS

A total of 94,291 patients (including 101 patients with NED and 94,190 patients without NED) were included. In the univariable analyses, NED was found to be correlated with a significantly poorer overall survival (hazard ratio (HR) of death = 3.09, 95% CI 2.42-3.95, P < 0.001) and cancer-specific survival (HR of death = 3.77, 95% CI 2.94-4.83, P < 0.001). Moreover, NED remained independently correlated with overall survival (HR of death = 1.84, 95% CI 1.34-2.51, P < 0.001) and cancer-specific survival (HR of death = 2.01, 95% CI 1.45-2.79, P < 0.001) after adjusting in multivariable and propensity score analyses. Furthermore, further stratification analyses indicated that the influence of NED on survival was not affected by tumor location, differentiation, T stage, and distant metastasis status; however, it was found to be associated with lymph node metastasis.

CONCLUSIONS

NED is associated with poor survival outcomes among colorectal cancer patients, especially in those with positive lymph nodes.

Colorectal Neuroendocrine Neoplasms: Areas of Unmet Need

The subject of colorectal neuroendocrine neoplasms (NENs), subdivided into well-differentiated NENs, termed neuroendocrine tumours (NETs; grade (G) 1 and 2), and poorly differentiated NENs, termed neuroendocrine carcinomas (NECs; G3) according to the 2010 World Health Organisation (WHO) classification, has arguably not had as much attention or study as NENs occurring in other sites. Colorectal NETs and NECs are however easier to study than many others since they are usually not difficult to remove and are increasingly detected because of intensified colorectal cancer screening and surveillance programmes. Colorectal NETs and NECs show site-specific heterogeneity with variable behaviour and different therapeutic options; these various aspects provide unique challenges. Because of bowel cancer screening programmes, colorectal NENs, like conventional adenocarcinomas, may be diagnosed at a stage that is associated with improved survival. In this article we intend to describe and define areas of unmet needs relating to the epidemiology, classification, pathology, diagnosis and therapy of colorectal NETs (including NETs G3), colorectal NECs, and finally, mixed adeno-neuroendocrine carcinomas (MANECs) by reviewing and discussing the relevant literature.

Tumor-associated Macrophages and Neuroendocrine Differentiation Decrease the Efficacy of Bevacizumab Plus Chemotherapy in Patients With Advanced Colorectal Cancer

BACKGROUND

In the present study, we investigated the prognostic and predictive role of neuroendocrine differentiation (NED) and tumor-associated macrophage (TAM) infiltration in tumor tissue from patients with advanced colorectal cancer who had received bevacizumab plus chemotherapy.

PATIENTS AND METHODS

A total of 123 consecutive patients with advanced colorectal cancer who had received bevacizumab plus irinotecan/oxaliplatin-based combination chemotherapy were included in the present study. In addition to the clinicopathologic parameters, the presence of NED and the level of TAM infiltration were studied as covariates for survival analysis.

RESULTS

The median patient age was 57 years (range, 30-76 years). The chemotherapy backbone was FOLFIRI (folinic acid, 5-fluorouracil, irinotecan) for 75% of the patients. Univariate analysis showed that only NED and TAM infiltration were significant predictive factors for progression-free survival. Left-sided tumors and low TAM infiltration were favorable factors for overall survival on univariate analysis. However, the TAM level was the only independent prognostic factor for overall survival (hazard ratio, 0.301; 95% confidence interval, 0.102-0.892).

CONCLUSION

Our results suggest that increased TAM infiltration in tumor tissue and NED could decrease the efficacy of bevacizumab plus combination chemotherapy in patients with advanced colorectal cancer. TAM infiltration in the tumor tissue could be used as a biomarker in patients with advanced colorectal cancer receiving bevacizumab plus chemotherapy.