Histogenesis and prognostic value of myenteric spread in colorectal cancer: a Japanese multi-institutional study

Pathological-Features-Modified TNM Staging System Improves Prognostic Accuracy for Rectal Cancer

BACKGROUND

Variations in survival outcomes are observed in the eighth edition of the American Joint Committee on Cancer TNM staging system.

OBJECTIVE

Machine learning ensemble methods were used to develop and evaluate the effectiveness of a pathological-features-modified TNM staging system in predicting survival for patients with rectal cancer by use of commonly reported pathological features, such as histological grade, tumor deposits, and perineural invasion, to improve the prognostic accuracy.

DESIGN

This was a retrospective population-based study.

SETTINGS

Data were assessed from the database of the Surveillance, Epidemiology, and End Results Program.

PATIENTS

The study cohort comprised 14,468 patients with rectal cancer diagnosed between 2010 and 2015. The development cohort included those who underwent surgery as the primary treatment, whereas patients who received neoadjuvant therapy were assigned to the validation cohort.

MAIN OUTCOME MEASURES

The primary outcome measures included cumulative rectal cancer survival, adjusted HRs, and both calibration and discrimination statistics to evaluate model performance and internal validation.

RESULTS

Multivariable Cox regression analysis identified all 3 pathological features as prognostic factors, after which patients were categorized into 4 pathological groups based on the number of pathological features (ie, 0, 1, 2, and 3). Distinct survival differences were observed among the groups, especially with patients with stage III rectal cancer. The proposed pathological-features-modified TNM staging outperformed the TNM staging in both the development and validation cohorts.

LIMITATIONS

Retrospective in design and lack of external validation.

CONCLUSIONS

The proposed pathological-features-modified TNM staging could complement the current TNM staging by improving the accuracy of survival estimation of patients with rectal cancer. See Video Abstract .

EL SISTEMA DE ESTADIFICACIN TNM CON CARACTERSTICAS PATOLGICAS MODIFICADO MEJORA LA PRECISIN DEL PRONSTICO DEL CNCER DE RECTO

ANTECEDENTES:Se observan variaciones en los resultados de supervivencia en el sistema de estadificación TNM del Comité Conjunto Americano del Cáncer 8º ediciónOBJETIVO:Se utilizaron métodos conjuntos de aprendizaje automático para desarrollar y evaluar la eficacia de un sistema de estadificación con características patológicas modificadas de tumores, ganglios y metástasis para predecir la supervivencia de pacientes con cáncer de recto, utilizando algunas características patológicas comúnmente informadas, como el grado histológico, depósitos tumorales e invasión perineural, para mejorar la precisión del pronóstico.DISEÑO:Este fue un estudio retrospectivo de base poblacional.ENTERNO CLINICO:Se recuperaron y evaluaron datos de la base de datos de Vigilancia, Epidemiología y Resultados Finales.PACIENTES:La cohorte del estudio estuvo compuesta por 14,468 pacientes con cáncer de recto diagnosticados entre 2010 y 2015. La cohorte de desarrollo incluyó a aquellos que se sometieron a cirugía como tratamiento primario, mientras que los pacientes que recibieron terapia neoadyuvante fueron asignados a la cohorte de validación.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas de resultado primarias incluyeron supervivencia acumulada del cáncer de recto, índices de riesgo ajustados y estadísticas de calibración y discriminación para evaluar el rendimiento del modelo y la validación interna.RESULTADOS:El análisis de regresión multivariable de Cox identificó las tres características patológicas como factores pronósticos, después de lo cual los pacientes se clasificaron en cuatro grupos patológicos según el número de características patológicas (es decir, 0, 1, 2 y 3). Se observaron distintas diferencias en la supervivencia entre los grupos, especialmente en los pacientes en estadio III. La estadificación propuesta con características patológicas modificadas de tumores-ganglios-metástasis superó a la estadificación TNM tanto en las cohortes de desarrollo como en las de validación.LIMITACIONES:Diseño retrospectivo y falta de validación externa.CONCLUSIONES:La estadificación propuesta con características patológicas modificadas de tumores-ganglios-metástasis podría complementar la estadificación TNM actual al mejorar la precisión de la estimación de supervivencia de los pacientes con cáncer de recto. (Traducción- Dr. Francisco M. Abarca-Rendon ).

The clinical relevance of adjuvant chemotherapy in locally advanced rectal cancer patients achieving near pathological complete response following neoadjuvant chemoradiotherapy: Insights from ypT stage

BACKGROUND

Near-pathological complete response (Near-pCR) patients constitute a distinct subgroup with limited research attention. The clinical relevance of adjuvant chemotherapy (ACT) in this patient cohort remains uncertain.

METHODS

We conducted a retrospective analysis of 245 patients with locally advanced rectal cancer (LARC) who achieved near-pCR following neoadjuvant chemoradiotherapy (NCRT) between 2011 and 2018. Based on their receipt of ACT or not (non-ACT), patients were divided into two groups. We examined their characteristics, treatment modalities, and survival outcomes, particularly focusing on 5-year disease-free survival (DFS) and 5-year overall survival (OS).

RESULTS

Among the 245 near-pCR patients, 191 (77.96%) received ACT, and 42 (17.14%) experienced disease recurrence. All 54 (22.04%) Patients in the non-ACT group exhibited a lower 5-year DFS rate (72.2% vs. 85.9%, P = 0.014) and a similar 5-year OS rate (87.0% vs. 91.1%, P = 0.351). Interestingly, those with ypT3-T4 stage tumors demonstrated a worse DFS (76.8% vs. 89.9%, P = 0.010) and OS (87.5% vs. 97.0%, P = 0.004) compared to their counterparts with ypT1-T2 stage tumors. Patients with Non-Downstage tumors showed inferior DFS (76.9% vs. 88.3%, P = 0.025) and OS (87.2% vs. 93.0%, P = 0.166) in comparison to patients with Downstage tumors. The ACT subgroup in patients with Downstage demonstrated statistically better 5-year DFS (93.0% vs. 71.4%, P = 0.001) but analogous survival rates for 5-year OS (OS: 94.0% vs. 89.3%, P = 0.402). Pathological T stage 3-4, perineural invasion (PNI) (positive) and ACT were independent factors influencing 5-year DFS in multivariate analysis. Both univariate and multivariate analysis demonstrated a link between serum carcinoembryonic antigen (CEA) before treatment ≥5 ng/ml and shorter 5-year OS. Notably, near-pCR patients with positive lymph nodes experienced notably diminished 5-year DFS in the absence of ACT post-surgery (61.1% vs. 93.2%, P < 0.001).

CONCLUSIONS

ACT demonstrated a significant positive impact on the prognosis of select near-pCR patients, particularly those with ypT1-T2 stage tumors and positive lymph nodes. ypT staging may emerge as a valuable criterion for precise post-surgical ACT guidance in near-pCR patients.

Clinicopathological differences of high Fusobacterium nucleatum levels in colorectal cancer: A review and meta-analysis

Objective

To systematically evaluate the significance of Fusobacterium nucleatum (Fn) levels the clinicopathological impacts of cancer.

Methods

Literature from Pubmed, Embase, and Web of Science was retrieved to collect all English literatures on the correlation between Fn and cancer, and the quality of literatures collected was assessed based on the Newcastle-Ottawa Quality Assessment Scale. The heterogeneity and sensitivity were detected by Stata 14.0 software, and the correlation between Fn and cancer clinicopathological as the effect variables was assessed according to the odds ratio (OR) and 95% confidence interval (CI). The forest plot was drawn.

Results

A total of 19 articles meeting the inclusion criteria were selected. The incidence of Fn prevalence varied considerably (range: 6.1 to 83.3%) and was greater than 10% in 13 of 19 studies. Compared with those with no/low Fn levels, the high levels of Fn was positively associated with vascular invasion, nerve invasion, depth of invasion, and distant metastasis [vascular invasion: OR = 1.66, 95%CI(1.07, 2.57), I² = 21.9%, fixed effect model; nerve invasion: OR = 1.36, 95%CI(1.00, 1.84), I² = 43.1%, fixed effect model; infiltration depth: OR = 1.94, 95%CI(1.20, 3.15), I² = 67.2%, random effect model; distant metastasis: OR = 1.80, 95%CI(1.23, 2.64), I² = 3.4%, fixed effect model]. Patients with MLH1 methylation always present a higher Fn levels than those without methylation [OR = 2.53, 95%CI(1.42, 4.53), P = 0.01, I² = 57.5%, random effect model]. Further, Fn was associatedwith the molecular characteristics of cancers [MSI-H Vs. MSS/MSI-low: OR = 2.92, 95%CI(1.61, 5.32), P = 0.01, I² = 63.2%, random effect model; High Vs. Low/Negative CIMP: OR = 2.23, 95%CI(1.64, 3.03), P = 0.01, I² = 64.2%, random effect model; KRAS mutation Vs. wild-type: OR = 1.24, 95%CI(1.04, 1.48), P = 0.02, I² = 27.0%, fixed effect model; Present Vs. Abscent BRAF mutations: OR = 1.88, 95%CI(1.44, 2.45), P = 0.01, I² = 24.2%, fixed effect model]. The cancer patients with high levels of Fn often have worse RFS than those with no/low Fn levels[OR = 1.14, 95%CI(0.61, 1.68), P = 0.01, I² = 80.7%, random effect model].

Conclusion

This review and meta-analysis showed that Fn could be used to predict unfavorable prognosis and function as potential prognostic biomarkers in colorectal cancer (CRC). Our data may have implications for targeting Fn to develop strategies for cancer prevention and treatment.

Three-dimensional imaging of intramural perineural invasion in colorectal cancer: Three-dimensional reconstruction approach with multiple immunohistochemically stained sections

Perineural invasion (PNI) at Auerbach's plexus in colorectal cancer (CRC), known as intramural PNI, is associated with adverse prognostic outcomes. This study aimed to characterize the three-dimensional (3D) architecture of CRC with intramural PNI and to evaluate the morphological features of tumor invasion around nerve tissue. Serial tissue sections from two cases of CRC were stained with cytokeratin AE1/AE3 and an anti-S-100 protein antibody. 3D models were reconstructed by scanning the virtual slides. In one case, intramural PNI was observed at the horizontal invasive front. The 3D reconstruction model showed tumor cells that appeared to infiltrate along the nervous meshwork, the structure of which was preserved. In the other case, intramural PNI was observed both at and behind the horizontal invasive front, and the 3D reconstruction model showed that the tumor cells appeared to be involved with nerve cells at the focal part of the horizontal invasive front. However, the nervous meshwork structure was not well identified in cancer-involved areas. This is the first study to characterize the 3D structure of tumor invasion around nerve tissue in CRC, demonstrating the morphological features of intramural PNI in CRC.

Feasibility and Performance of Elastin Trichrome as a Primary Stain in Colorectal Cancer Resection Specimens: Results of an Interobserver Variability Study

Venous invasion (VI) is a powerful prognostic factor in colorectal cancer (CRC) that is widely underreported. The ability of elastin stains to improve VI detection is now recognized in several international CRC pathology protocols. However, concerns related to the cost and time required to perform and evaluate these stains in addition to routine hematoxylin and eosin (H&E) stains remains a barrier to their wider use. We therefore sought to determine whether an elastin trichrome (ET) stain could be used as a "stand-alone" stain in CRC resections, by comparing the sensitivity, accuracy, and reproducibility of detection of CAP-mandated prognostic factors using ET and H&E stains. Representative H&E- and ET-stained slides from 50 CRC resections, including a representative mix of stages and prognostic factors, were used to generate 2 study sets. Each case was represented by H&E slides in 1 study set and by corresponding ET slides from the same blocks in the other study set. Ten observers (3 academic gastrointestinal [GI] pathologists, 4 community pathologists, 3 fellows) evaluated each study set for CAP-mandated prognostic factors. ET outperformed H&E in the assessment of VI with respect to detection rates (50% vs. 28.6%; P<0.0001), accuracy (82% vs. 59%, P<0.0001), and reproducibility (k=0.554 vs. 0.394). No significant differences between ET and H&E were observed for other features evaluated. In a poststudy survey, most observers considered the ease and speed of assessment at least equivalent for ET and H&E for most prognostic factors, and felt that ET would be feasible as a stand-alone stain in practice. If validated by others, our findings support the use of ET, rather than H&E, as the primary stain for the evaluation of CRC resections.

Morphology of enteric glia in colorectal carcinoma: A comparative study of tumor site and its proximal normal margin

OBJECTIVE

Colorectal carcinoma (CRC) is the third most common cancer in the world and fifth most common cancer in India. To understand the extent of perineural invasion (PNI) in CRC it is essential to study the morphology of enteric glial cells (EGCs). The aim of the study was to analyze the numerical density of EGCs and area of myenteric ganglia (MG) in the colonic tissue samples collected from CRC patients.

MATERIAL AND METHODS

Fifteen intraoperative tissue specimens were collected from the tumor site and 2cm proximal to the upper extent of tumor. The samples were divided into four groups: group 1 (n=15): proximal tumor free colonic tissue; group 2 (n=3): well-differentiated; group 3 (n=8): moderately differentiated; group 4 (n=4): poorly differentiated adenocarcinoma. After processing the tissues were subjected to hematoxylin and eosin staining. The anti-S100β and anti-GFAP antibodies were used to observe the EGCs.

RESULTS

In the H&E stained sections the number of myenteric ganglia appeared to be decreasing with increasing grade of adenocarcinoma. Immunostaining showed significant decreasing pattern in the numerical density of EGCs per myenteric ganglion and mean area of myenteric ganglia in relation to the thickness of circular muscle, corresponding to the increasing grades of adenocarcinoma. The morphology of the EGCs remained unaltered in the colonic tissue adjacent to the tumor site.

CONCLUSION

Significant loss of EGCs and neurodegeneration corresponded with the grade of tumor emphasizing on its prognostic value. The PNI was not seen in the clear margin proximal to the tumor site.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

Pathologic assessment of colorectal cancer resection specimens plays an important role in postsurgical management and prognostication in patients with colorectal cancer. Challenges exist in the evaluation and reporting of these specimens, either because of difficulties in applying existing guidelines or related to newer concepts.

Objective.—

To address challenging areas in colorectal cancer pathology and to provide an overview of the literature, current guidelines, and expert recommendations for the handling of colorectal cancer resection specimens in everyday practice.

Data Sources.—

PubMed (US National Library of Medicine, Bethesda, Maryland) literature review; reporting protocols of the College of American Pathologists, the Royal College of Pathologists of the United Kingdom, and the Japanese Society for Cancer of the Colon and Rectum; and classification manuals of the American Joint Committee on Cancer and the Union for International Cancer Control.

Conclusions.—

This review has addressed issues and challenges affecting quality of colorectal cancer pathology reporting. High-quality pathology reporting is essential for prognostication and management of patients with colorectal cancer.

Colorectal Cancer Cells Adhere to and Migrate Along the Neurons of the Enteric Nervous System

BACKGROUND & AIMS

In several types of cancers, tumor cells invade adjacent tissues by migrating along the resident nerves of the tumor microenvironment. This process, called perineural invasion, typically occurs along extrinsic nerves, with Schwann cells providing physical guidance for the tumor cells. However, in the colorectal cancer microenvironment, the most abundant nervous structures belong to the nonmyelinated intrinsic enteric nervous system (ENS). In this study, we investigated whether colon cancer cells interact with the ENS.

METHODS

Tumor epithelial cells (TECs) from human primary colon adenocarcinomas and cell lines were cocultured with primary cultures of ENS and cultures of human ENS plexus explants. By combining confocal and atomic force microscopy, as well as video microscopy, we assessed tumor cell adhesion and migration on the ENS. We identified the adhesion proteins involved using a proteomics approach based on biotin/streptavidin interaction, and their implication was confirmed further using selective blocking antibodies.

RESULTS

TEC adhered preferentially and with stronger adhesion forces to enteric nervous structures than to mesenchymal cells. TEC adhesion to ENS involved direct interactions with enteric neurons. Enteric neuron removal from ENS cultures led to a significant decrease in tumor cell adhesion. TECs migrated significantly longer and further when adherent on ENS compared with on mesenchymal cells, and their trajectory faithfully followed ENS structures. Blocking N-cadherin and L1CAM decreased TEC migration along ENS structures.

CONCLUSIONS

Our data show that the enteric neuronal network guides tumor cell migration, partly via L1CAM and N-cadherin. These results open a new avenue of research on the underlying mechanisms and consequences of perineural invasion in colorectal cancer.

Clinical significance of perineural invasion in stages II and III colorectal cancer

PURPOSE

This study aimed to determine the prognostic value of perineural invasion (PNI) in patients with colorectal cancer (CRC), particularly patients with TNM stage II and stage III.

METHODS

A total of 159 CRC patients who had undergone radical resection were retrospectively analyzed. Histopathological evaluation of tissue samples was conducted on hematoxylin and eosin-stained sections. PNI was considered positive when cancer cells were observed inside the nerve sheath, or when at least 33% of the nerve periphery was surrounded by cancer cells. A 3-tier grading system (PNI0, PNI1, PNI2) based on the depth of PNI was used to assess the localization of PNI in the bowel. PNI and other prognostic factors were evaluated by survival analysis.

RESULTS

PNI status in CRC significantly affected postoperative overall survival (P<0.001). The five-year survival rates for PNI-negative and PNI-positive patients were 77% and 32%, respectively. PNI was closely correlated with tumor gross type, tumor grade, depth of invasion, lymph node metastasis, clinical stage, vessel invasion, tumor budding grade, and tumor growth pattern. Multivariate analysis revealed that PNI was an independent prognostic factor (HR=2.223, P=0.003). The survival of PNI-positive patients was significantly poorer than that of PNI-negative patients in stages II and III (P=0.003 and P=0.008, respectively). The overall survival of colorectal patients was in the descending order of PNI-negative at stage II, PNI-positive at stage II/PNI-negative at stage III, and PNI-positive at stage III (P<0.001). When the PNI status and T stage were considered together, overall survival curves of the PNI2 patients were significantly worse than those of PNI1 patients in pT4 stage (P=0.019).

CONCLUSIONS

PNI is a poor independent prognostic factor for CRC. It could complement classic TNM staging classification in stratifying CRC patients in stages II and III. Assessment of the site-specific distribution of PNI may further enhance the impact of PNI contribution to the prognosis of CRC.