Perineural Invasion is a Strong Prognostic Factor in Colorectal Cancer: A Systematic Review.Am J Surg Pathol. 2016;40:103-112. [PMID: 26426380 DOI: 10.1097/PAS.0000000000000518]

Prognostic Factors and the Role of Adjuvant Chemotherapy in Pathological Node-Negative T3 Gastric Cancer

The role of adjuvant chemotherapy in pathological T3N0M0 (pT3N0M0) gastric cancer (GC) remains unclear. The aim of this study was to analyze the prognostic factors of patients with pT3N0M0 GC and to clarify which ones could benefit from adjuvant chemotherapy. A total of 137 patients with pT3N0M0 GC were recruited between 1994 and 2020. Clinicopathological factors and adjuvant chemotherapy regimens were retrospectively collected. Prognostic factors of disease-free survival (DFS) and cancer-specific survival (CSS) were determined using univariate and multivariate analyses. The chemotherapy group was younger (p = 0.012), had had more lymph nodes retrieved (p = 0.042) and had higher percentages of vascular invasion (p = 0.021) or perineural invasion (p = 0.030) than the non-chemotherapy group. There were no significant differences in DFS (p = 0.222) and CSS (p = 0.126) between patients treated with or without adjuvant chemotherapy. Stump cancer, tumor size and perineural invasion were associated with higher rates of recurrence. Tumor size was an independent prognostic factor for DFS (hazard ratio, 4.55; confidence interval, 1.59-12.99; p = 0.005) and CSS (hazard ratio, 3.97; confidence interval, 1.38-11.43; p = 0.011). Tumor size independently influenced survival outcomes in pT3N0M0 patients who underwent radical surgery with and without adjuvant chemotherapy.

Radiation Therapy Exacerbates Tumor-Promoting Innervation and Nerve Signaling in Rectal Cancer

PURPOSE

Many solid tumors present with perineural invasion (PNI), and innervation correlates with worsened prognosis. The effects that commonly administered therapies such as radiation therapy (RT) have on PNI status remain unknown. We investigated the contribution of RT on the nervous system and elucidated the implications that increased nerve signaling can have on tumor burden using our previously developed orthotopic murine model of rectal cancer (RC) and our targeted and clinically relevant short-course RT (SCRT) regimen.

METHODS

Medical charts for patients with RC treated at the Wilmot Cancer Institute were obtained and PNI status was analyzed. Human data were accompanied by an orthotopic murine model of RC. Briefly, luciferase-expressing murine colon-38 (MC38-luc) tumor cells were injected orthotopically into the rectal wall of C57BL6 mice. Targeted SCRT (5 gray (Gy) per fraction for 5 consecutive fractions) was administered to the tumor. Intratumoral innervation was determined by immunohistochemistry (IHC), local norepinephrine (NE) concentration was quantified by enzyme-linked immunosorbent assay (ELISA), and β2-adrenergic receptor (B2AR) expression was assessed by flow cytometry. Chronic NE signaling was mirrored by daily isoproterenol treatment, and the effect on tumor burden was determined by overall survival, presence of metastatic lesions, and tumor size. Isoproterenol signaling was inhibited by administration of propranolol.

RESULTS

Human RC patients with PNI have decreased overall survival compared with patients without PNI. In our mouse model, SCRT induced the expression of genes involved in neurogenesis, increased local NE secretion, and upregulated B2AR expression. Treating mice with isoproterenol resulted in decreased overall survival, increased rate of metastasis, and reduced SCRT efficacy. Interestingly, the isoproterenol-induced decrease in SCRT efficacy could be abrogated by blocking the BAR through the use of propranolol, suggesting a direct role of BAR stimulation on impairing SCRT responses.

CONCLUSIONS

Our results indicate that while SCRT is a valuable treatment, it is accompanied by adverse effects on the nervous system that may impede the efficacy of therapy and promote tumor burden. Therefore, we could speculate that therapies aimed at targeting this signaling cascade or impairing nerve growth in combination with SCRT may prove beneficial in future cancer treatment.

Prognostic value of lymphovascular and perineural invasion in colorectal cancer

Background/Aim: Lymphovascular and perineural invasion (LVI and PNI, respectively) are associated with poor prognosis in various cancers. We sought to identify clinical variables associated with LVI and PNI in colorectal cancer (CRC) and their effects on survival. Methods: Our study design is consistent with a retrospective cohort study. Data from 237 patients with documented LVI or PNI who underwent surgery for colorectal cancer between 2017 and 2021 were retrospectively reviewed. Demographic characteristics, surgery and pathology reports, disease-free and overall survival (DFS and OS, respectively) of the patients were examined. Results: When the DFS duration of the patients were evaluated, The mean DFS of the LVI-negative group was 27.4 (15.09) months, and the mean of the LVI-positive patients was 20.45 (13) months. DFS was longer in the LVI-negative group (P<0.001). DFS was 52.26 (1.89) months in PNI-negative patients and 34.29 (2.71) months in PNI-positive patients. DFS expectation of PNI-positive patients was approximately 18 months less than that of negative patients (P<0.001). When the patients were evaluated in terms of OS duration, no significant difference was observed in LVI-negative and -positive patient groups, while the estimated OS duration was 52.29 (1.84) months in PNI-negative patients, and 40.10 (2.49) months in PNI-positive patients. OS was 12 months shorter in PNI-negative patients (P<0.001). Conclusion: The use of PNI and LVI together was found to have a significant impact on the survival rates of patients with colorectal cancer. Documenting LVI and PNI status in biopsy specimens can aid in the management, prognosis, and decision-making for treating colorectal tumors.

Expectation-maximization algorithm leads to domain adaptation for a perineural invasion and nerve extraction task in whole slide digital pathology images

In addition to lymphatic and vascular channels, tumor cells can also spread via nerves, i.e., perineural invasion (PNI). PNI serves as an independent prognostic indicator in many malignancies. As a result, identifying and determining the extent of PNI is an important yet extremely tedious task in surgical pathology. In this work, we present a computational approach to extract nerves and PNI from whole slide histopathology images. We make manual annotations on selected prostate cancer slides once but then apply the trained model for nerve segmentation to both prostate cancer slides and head and neck cancer slides. For the purpose of multi-domain learning/prediction and investigation on the generalization capability of deep neural network, an expectation-maximization (EM)-based domain adaptation approach is proposed to improve the segmentation performance, in particular for the head and neck cancer slides. Experiments are conducted to demonstrate the segmentation performances. The average Dice coefficient for prostate cancer slides is 0.82 and 0.79 for head and neck cancer slides. Comparisons are then made for segmentations with and without the proposed EM-based domain adaptation on prostate cancer and head and neck cancer whole slide histopathology images from The Cancer Genome Atlas (TCGA) database and significant improvements are observed.

Lymphovascular invasion represents a superior prognostic and predictive pathological factor of the duration of adjuvant chemotherapy for stage III colon cancer patients

BACKGROUND

Lymphovascular invasion (LVI) and perineural invasion (PNI) can indicate poor survival outcomes in colorectal cancer, but few studies have focused on stage III colon cancer. The current study aimed to confirm the prognostic value of LVI and PNI and identify patients who could benefit from a complete duration of adjuvant chemotherapy based on the two pathological factors.

METHODS

We enrolled 402 consecutive patients with stage III colon cancer who received colon tumor resection from November 2007 to June 2016 at Sun Yat-sen University Cancer Center. Survival analyses were performed by using Kaplan-Meier method with log-rank tests. Risk factors related to disease-free survival (DFS) and overall survival (OS) were identified through Cox proportional hazards analysis.

RESULTS

141 (35.1%) patients presented with LVI, and 108 (26.9%) patients with PNI. The LVI-positive group was associated with poorer 3-year DFS (86.5% vs. 76.3%, P = 0.001) and OS (96.0% vs. 89.1%, P = 0.003) rates compared with the LVI-negative group. The PNI-positive group showed a worse outcome compared with the PNI-negative group in 3-year DFS rate (72.5% vs. 86.7%, P < 0.001). Moreover, LVI-positive group present better 3-year DFS and OS rate in patients completing 6-8 cycles of adjuvant chemotherapy than those less than 6 cycles (3-year DFS: 80.0% vs. 64.9%, P = 0.019; 3-year OS: 93.2% vs. 76.3%, P = 0.002).

CONCLUSIONS

LVI is a superior prognostic factor to PNI in stage III colon cancer patients undergoing curative treatment. PNI status can noly predict the 3-year DFS wihout affecting the 3-year OS. Furthermore, LVI also represents an effective indicator for adjuvant chemotherapy duration.

Prognosis of mucinous colon cancer is determined by histological biomarkers rather than microsatellite instability

The prognostic value of microsatellite instability (MSI), as well as other histological characteristics such as lymphovascular invasion (LI), perineural invasion (PNI) and extramural vascular invasion (EMVI), is unclear in colorectal mucinous carcinoma (MC). This study aims to determine the relevance of these factors in MC patients and analyses the role of MSI in stage III MC patients treated with adjuvant chemotherapy. A cohort of 650 patients diagnosed with stages I-IV colonic MC from 2000 to 2010 was selected from PALGA, the nationwide Dutch pathology databank. Histopathology was revised and mismatch repair (MMR) status determined. Univariate and multivariate survival analyses were performed. Deficient MMR (dMMR) was found in 33% of MCs and correlated with female gender and right-sidedness, but also with lower tumour stage (stages I/II: 73.2 versus 47%; P < 0.0001) and the absence of EMVI (9.7 versus 23.7%; P < 0.0001) and PNI (5.6 versus 12.7%; P = 0.005). On univariate analysis OS was better for dMMR MC than for proficient MMR (pMMR) MC (median OS of 9.7 versus 5.0 years; P = 0.009), but MMR status was no longer a relevant prognostic factor on multivariate analysis [hazard ratio (HR) = 0.91, 95% confidence interval (CI) = 0.70-1.18]. Stage III MC patients benefited from adjuvant chemotherapy, and dMMR status was associated with better OS in this group (HR = 0.35, 95% CI = 0.13-0.94). EMVI, LI and PNI, but not MMR, status are independent prognostic factors for survival in MC patients. Stage III MC patients benefit from adjuvant chemotherapy and dMMR status is associated with improved survival when adjuvant chemotherapy is given.

Nerves in gastrointestinal cancer: from mechanism to modulations

Maintenance of gastrointestinal health is challenging as it requires balancing multifaceted processes within the highly complex and dynamic ecosystem of the gastrointestinal tract. Disturbances within this vibrant environment can have detrimental consequences, including the onset of gastrointestinal cancers. Globally, gastrointestinal cancers account for ~19% of all cancer cases and ~22.5% of all cancer-related deaths. Developing new ways to more readily detect and more efficiently target these malignancies are urgently needed. Whereas members of the tumour microenvironment, such as immune cells and fibroblasts, have already been in the spotlight as key players of cancer initiation and progression, the importance of the nervous system in gastrointestinal cancers has only been highlighted in the past few years. Although extrinsic innervations modulate gastrointestinal cancers, cells and signals from the gut's intrinsic innervation also have the ability to do so. Here, we shed light on this thriving field and discuss neural influences during gastrointestinal carcinogenesis. We focus on the interactions between neurons and components of the gastrointestinal tract and tumour microenvironment, on the neural signalling pathways involved, and how these factors affect the cancer hallmarks, and discuss the neural signatures in gastrointestinal cancers. Finally, we highlight neural-related therapies that have potential for the management of gastrointestinal cancers.

The Challenges of Colorectal Cancer Surgery during the COVID-19 Pandemic in Romania: A Three-Year Retrospective Study

The predictions on the influence of the SARS-CoV-2 pandemic on access to medical services in Romania predicted a 35% drop in oncological hospitalizations in 2020 compared to the previous decade, raising the hypothesis that patients with colorectal cancer can become indirect victims of the ongoing pandemic. Therefore, the aim of the current research was to observe how the COVID-19 pandemic influenced colorectal cancer surgery in Romania, to determine the level of addressability towards specialized care, to compare the cancer staging between the pandemic and pre-pandemic periods, and to observe the risk factors for disease progression. This retrospective study was spread over three years, respectively, from March 2019 to March 2022, and included a total of 198 patients with a history of colorectal cancer surgery. It was decided to perform a parallel comparison of 2019, 2020, and 2021 to observe any significant changes during the pandemic. Our clinic encountered a significant decrease in all interventions during the pandemic; although the number of CRC surgeries remained constant, the cases were more difficult, with significantly more patients presenting in emergency situations, from 31.3% in 2019 to 50.0% in 2020 and 57.1% in 2021. Thus, the number of elective surgeries decreased significantly. The proportion of TNM (tumor-node-metastasis) staging was, however, statistically significant between the pre-pandemic and pandemic period. In 2019, 13.3% of patients had stage IIa, compared with 28.8% in 2020 and 13.1% in 2021. Similarly, the proportion of very advanced colorectal cancer was higher during the pandemic period of 2020 and 2021 (12.0% in 2019 vs. 12.5% in 2020 and 25.0% in 2021), which was represented by a significantly higher proportion of patients with bowel perforation. Patients with an advanced TNM stage had a 6.28-fold increased risk of disease progression, followed by lymphovascular invasion (HR = 5.19). However, the COVID-19 pandemic, represented by admission years 2020 and 2021, did not pose a significant risk for disease progression and mortality. In-hospital mortality during the pandemic also did not change significantly. After the pandemic restrictions have been lifted, it would be advisable to conduct a widespread colorectal cancer screening campaign in order to identify any instances of the disease that went undetected during the SARS-CoV-2 pandemic.

Establishment and validation of a postoperative predictive model for patients with colorectal mucinous adenocarcinoma

BACKGROUND

The aim of this study was to develop comprehensive and effective nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) rates in patients with colorectal mucinous adenocarcinoma (CRMA).

METHODS

A total of 4711 CRMA patients who underwent radical surgery between 2010 and 2018 from the Surveillance, Epidemiology, and End Results (SEER) database were collected and randomized into development (n=3299) and validation (n=1412) cohorts at a ratio of 7:3 for model development and validation. OS and CSS nomograms were developed using the prognostic factors from the development cohort after multivariable Cox regression analysis. The performance of the nomograms was evaluated using Harrell's concordance index (C-index), calibration diagrams, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA).

RESULTS

The study included 4711 patients. Multivariate Cox regression analysis demonstrated that age, tumor size, grade, pT stage, pN stage, M stage, carcinoembryonic antigen, perineural invasion, tumor deposits, regional nodes examined, and chemotherapy were correlated with OS and CSS. Marital status was independently related to OS. In the development and validation cohorts, the C-index of OS was 0.766 and 0.744, respectively, and the C-index of CSS was 0.826 and 0.809, respectively. Calibration curves and ROC curves showed predictive accuracy. DCA showed that the nomograms had excellent potency over the 8th edition of the TNM staging system with higher clinical net benefits. Significant differences in OS and CSS were observed among low-, medium-, and high-risk groups.

CONCLUSIONS

Nomograms were developed for the first time to predict personalized 1-, 3-, and 5-year OS and CSS in CRMA postoperative patients. External and internal validation confirmed the excellent discrimination and calibration ability of the nomograms. The nomograms can help clinicians design personalized treatment strategies and assist with clinical decisions.

Predicting perineural invasion using histogram analysis of zoomed EPI diffusion-weighted imaging in rectal cancer

PURPOSE

To investigate the utility of histogram analysis of zoomed EPI diffusion-weighted imaging (DWI) for predicting the perineural invasion (PNI) status of rectal cancer (RC).

METHODS

This prospective study evaluated 94 patients diagnosed with histopathologically confirmed RC between July 2020 and July 2021. Patients underwent preoperative rectal magnetic resonance imaging (MRI) examinations, including the zoomed EPI DWI sequence. Ten whole-tumor histogram parameters of each patient were derived from zoomed EPI DWI. Reproducibility was evaluated according to the intra-class correlation coefficient (ICC). The association of the clinico-radiological and histogram features with PNI status was assessed using univariable analysis for trend and multivariable logistic regression analysis with β value calculation. Receiver operating characteristic (ROC) curve analysis was conducted to assess the diagnostic performance.

RESULTS

Forty-two patients exhibited positive PNI. The inter- and intraobserver agreements were excellent for the histogram parameters (all ICCs > 0.80). The maximum (p = 0.001), energy (p = 0.021), entropy (p = 0.021), kurtosis (p < 0.001), and skewness (p < 0.001) were significantly higher in the positive PNI group than in the negative PNI group. Multivariable analysis showed that higher MRI T stage [β = 2.154, 95% confidence interval (CI) 0.932-3.688; p = 0.002] and skewness (β = 0.779, 95% CI 0.255-1.382; p = 0.006) were associated with positive PNI. The model combining skewness and MRI T stage had an area under the ROC curve of 0.811 (95% CI 0.724-0.899) for predicting PNI status.

CONCLUSION

Histogram parameters in zoomed EPI DWI can help predict the PNI status in RC.

Risk of Local Recurrence After Complete Mesocolic Excision for Right-Sided Colon Cancer: Post-Hoc Sensitivity Analysis of a Population-Based Study

BACKGROUND

A causal treatment effect of complete mesocolic excision for right-sided colon cancer on the risk of recurrence has been shown, but it is still unclear whether this is caused solely by a risk reduction of local recurrence.

OBJECTIVE

The goal of this study was to assess to what extent complete mesocolic excision contributes to the risk of local recurrence.

DESIGN

This study was a posthoc analyses of data from a population-based cohort. Inverse probability of treatment weighting and competing risk analyses were used to estimate the possible causal effects of complete mesocolic excision.

SETTING

Data were collected from the 4 public colorectal cancer centers in the Capital Region of Denmark.

PATIENTS

Patients undergoing elective colon resections for right-sided colon cancer without distant metastases during the period 2010-2013 were included. One center performed complete mesocolic excision and the remaining 3 centers performed conventional resections.

MAIN OUTCOME MEASURES

The primary outcome was the cumulative incidence of solely local recurrence 5.2 years after surgery. Secondary outcomes were solely distant recurrence and both local and distant recurrence diagnosed within 180 days.

RESULTS

A total of 807 patients were included with 186 undergoing complete mesocolic excision and 621 conventional resections. The 5.2-year cumulative incidence of a solely local recurrence was 3.7% (95% CI, 0.5-6.1) after complete mesocolic excision compared with 7.0% (5.0-8.9) in the control group, and the absolute risk reduction of complete mesocolic excision was 3.7% (2.5-7.1; p = 0.035). The absolute risk reduction on local and distant recurrence was 3.4% (1.3-5.6; p = 0.002) and on solely distant recurrence was 3.1% (0.0-6.2; p = 0.052).

LIMITATIONS

The recurrence risk after conventional resection might be underestimated by the use of inappropriate modalities to diagnose local recurrence for some patients and the shorter duration in this group.

CONCLUSION

This study shows a causal treatment effect of complete mesocolic excision on the risk of a solely local recurrence and of distant recurrence with or without local recurrence. See Video Abstract at http://links.lww.com/DCR/B832 .RIESGO DE RECURRENCIA LOCAL DESPUÉS DE LA ESCISIÓN MESOCÓLICA COMPLETA PARA EL CÁNCER DE COLON DEL LADO DERECHO: ANÁLISIS DE SENSIBILIDAD POST-HOC DE UN ESTUDIO POBLACIONALANTECEDENTES:Se ha demostrado un efecto del tratamiento causal de la escisión mesocólica completa para el cáncer de colon del lado derecho sobre el riesgo de recurrencia, pero aún no está claro si esto se debe únicamente a una reducción del riesgo de recurrencia local.OBJETIVO:Evaluar en qué medida la escisión mesocólica completa se atribuye al riesgo de recurrencia local.DISEÑO:Análisis posthoc de datos de una cohorte poblacional. Se utilizaron análisis de probabilidad inversa de ponderación del tratamiento y de riesgo competitivo para estimar los posibles efectos causales de la escisión mesocólica completa.AJUSTE:Datos de los cuatro centros públicos de cáncer colorrectal en la Región Capital de Dinamarca.PACIENTES:Pacientes sometidos a resecciones de colon electivas por cáncer de colon derecho sin metástasis a distancia durante el período 2010-2013. Un centro realizó escisión mesocólica completa, el resto resecciones convencionales.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la incidencia acumulada de la recidiva local únicamente, 5,2 años después de la cirugía. Los resultados secundarios fueron únicamente la recidiva a distancia y ambas,la recidiva local y a distancia diagnosticada dentro de los 180 días.RESULTADOS:Se incluyeron un total de 807 pacientes, 186 sometidos a escisión mesocólica completa y 621 resecciones convencionales. La incidencia acumulada de 5,2 años de una recidiva únicamente local fue del 3,7% (IC del 95%: 0,5 a 6,1) después de la escisión mesocólica completa en comparación con el 7,0% (5,0 a 8,9) en el grupo de control, y la reducción del riesgo absoluto de la escisión mesocólica completa fue del 3,7% (2,5-7,1; p = 0,035). La reducción del riesgo absoluto de recidiva local y distante fue del 3,4% (1,3-5,6; p = 0,0019) y de recidiva únicamente a distancia 3,1% (0,0-6,2; p = 0,052).LIMITANTES:El riesgo de recurrencia después de la resección convencional podría subestimarse por el uso de modalidades inapropiadas para el diagnostico de la recurrencia local en algunos pacientes y la duración más corta en este grupo.CONCLUSIÓN:Este estudio muestra un efecto del tratamiento causal de la escisión mesocólica completa sobre el riesgo de una recidiva únicamente local y de recidiva a distancia con o sin recidiva local. Consulte Video Resumen en http://links.lww.com/DCR/B832 . (Traducción-Dr. Mauricio Santamaria ).

Computed tomography-based radiomics nomogram for the preoperative prediction of perineural invasion in colorectal cancer: a multicentre study

PURPOSE

To develop and validate a computed tomography (CT) radiomics nomogram from multicentre datasets for preoperative prediction of perineural invasion (PNI) in colorectal cancer.

METHODS

A total of 299 patients with histologically confirmed colorectal cancer from three hospitals were enrolled in this retrospective study. Radiomic features were extracted from the whole tumour volume. The least absolute shrinkage and selection operator logistic regression was applied for feature selection and radiomics signature construction. Finally, a radiomics nomogram combining the radiomics score and clinical predictors was established. The receiver operating characteristic curve and decision curve analysis (DCA) were used to evaluate the predictive performance of the radiomics nomogram in the training cohort, internal validation and external validation cohorts.

RESULTS

Twelve radiomics features extracted from the whole tumour volume were used to construct the radiomics model. The area under the curve (AUC) values of the radiomics model in the training cohort, internal validation cohort, external validation cohort 1, and external validation cohort 2 were 0.82 (0.75-0.90), 0.77 (0.62-0.92), 0.71 (0.56-0.85), and 0.73 (0.60-0.85), respectively. The nomogram, which combined the radiomics score with T category and N category by CT, yielded better performance in the training cohort (AUC = 0.88), internal validation cohort (AUC = 0.80), external validation cohort 1 (AUC = 0.75), and external validation cohort 2 (AUC = 0.76). DCA confirmed the clinical utility of the nomogram.

CONCLUSIONS

The CT-based radiomics nomogram has the potential to accurately predict PNI in patients with colorectal cancer.

Pathologic Implications of Radial Resection Margin and Perineural Invasion to Adjuvant Chemotherapy after Preoperative Chemoradiotherapy and Surgery for Rectal Cancer: A Multi-Institutional and Case-Matched Control Study

We assessed the exact role of adjuvant chemotherapy after neoadjuvant chemoradiotherapy (CRT) and surgery in rectal cancer patients with positive surgical margin or perineural invasion (PNI). This multi-institutional study included 1799 patients with rectal cancer at cT3-4N0-2M0 stages. Patients were divided into two groups. The high-risk group had a positive margin and/or perineural invasion. The low-risk group showed no positive margin or PNI. Propensity-score matching analysis was performed, and a total of 928 patients, with 464 in each arm, were evaluated. The high-risk group showed significant differences in overall survival (OS, 73.4% vs. 53.9%, p < 0.01) and recurrence-free survival (RFS, 52.7% vs. 40.9%, p = 0.01) at five years between the adjuvant chemotherapy arm and observation arm. The low-risk group showed no significant differences in 5-year OS (p = 0.61) and RFS (p = 0.75) between the two arms. Multivariate analyses showed that age, pathologic N stage, and adjuvant chemotherapy were significantly correlated with OS and RFS in the high-risk group (all p < 0.05). Adjuvant chemotherapy improved OS and RFS more significantly in rectal cancer patients with positive surgical margin or PNI than in those with negative surgical margin and PNI.

A nomogram for predicting 10-year cancer specific survival in patients with pathological T3N0M0 rectal cancer

Background

The pathological T3N0M0 (pT3N0M0) rectal cancer is the earliest stage and has the best prognosis in the locally advanced rectal cancer, but the optimal treatment remains controversial. A reliable prognostic model is needed to discriminate the high-risk patients from the low-risk patients, and optimize adjuvant chemotherapy (ACT) treatment decisions by predicting the likelihood of ACT benefit for the target population.

Patients and methods

We gathered and analyzed 276 patients in Sun Yat-sen University Cancer Center from March 2005 to December 2011. All patients underwent total mesorectal excision (TME), without preoperative therapy, and were pathologically proven pT3N0M0 rectal cancer with negative circumferential resection margin (CRM). LASSO regression model was used for variable selection and risk factor prediction. Multivariable cox regression was used to develop the predicting model. Optimum cut-off values were determined using X-Tile plot analysis. The 10-fold cross-validation was adopted to validate the model. The performance of the nomogram was evaluated with its calibration, discrimination and clinical usefulness.

Results

A total of 188 patients (68.1%) had ACT and no patients had adjuvant radiotherapy. Age, monocyte percentage, carbohydrate antigen 19–9, lymph node dissection numbers and perineural invasion (PNI) were identified as significantly associated variables that could be combined for an accurate prediction risk of Cancer Specific Survival (CSS) for pT3N0M0 patients. The model adjusted for CSS showed good discrimination with a C-index of 0.723 (95% CI: 0.652–0.794). The calibration curves showed that the nomogram adjusted for CSS was able to predict 3-, 5-, and 10-year CSS accurately. The corresponding predicted probability was used to stratify high and low-risk patients (10-year CSS: 69.1% vs. 90.8%, HR = 3.815, 95%CI: 2.102–6.924, P < 0.0001). ACT improved overall survival (OS) in the low-risk patients (10-year OS: 91.9% vs. 83.3%, HR = 0.338, 95% CI: 0.135–0.848, P < 0.0001), while it did not exhibit a significant benefit in the high-risk patients.

Conclusion

The present study showed that age, monocyte percentage, carbohydrate antigen 19–9, lymph node dissection numbers and PNI were independent prognostic factors for pT3N0M0 rectal cancer patients. A nomogram based on these prognostic factors effectively predicts CSS in patients, which can be conveniently used in clinical practice. ACT may improve overall survival in the low-risk patients. But the benefit of ACT was not seen in the high-risk patients.

Emerging Roles of the Nervous System in Gastrointestinal Cancer Development

Simple Summary

Nerve–cancer cross-talk has increasingly become a focus of the oncology field, particularly in gastrointestinal (GI) cancers. The indispensable roles of the nervous system in GI tumorigenesis and malignancy have been dissected by epidemiological, experimental animal and mechanistic data. Herein, we review and integrate recent discoveries linking the nervous system to GI cancer initiation and progression, and focus on the molecular mechanisms by which nerves and neural receptor pathways drive GI malignancy.

Abstract

Our understanding of the fascinating connection between nervous system and gastrointestinal (GI) tumorigenesis has expanded greatly in recent years. Recent studies revealed that neurogenesis plays an active part in GI tumor initiation and progression. Tumor-driven neurogenesis, as well as neurite outgrowth of the pre-existing peripheral nervous system (PNS), may fuel GI tumor progression via facilitating cancer cell proliferation, chemoresistance, invasion and immune escape. Neurotransmitters and neuropeptides drive the activation of various oncogenic pathways downstream of neural receptors within cancer cells, underscoring the importance of neural signaling pathways in GI tumor malignancy. In addition, neural infiltration also plays an integral role in tumor microenvironments, and contributes to an environment in favor of tumor angiogenesis, immune evasion and invasion. Blockade of tumor innervation via denervation or pharmacological agents may serve as a promising therapeutic strategy against GI tumors. In this review, we summarize recent findings linking the nervous system to GI tumor progression, set the spotlight on the molecular mechanisms by which neural signaling fuels cancer aggressiveness, and highlight the importance of targeting neural mechanisms in GI tumor therapy.

Serum Extracellular Vesicle Stratifin Is a Biomarker of Perineural Invasion in Patients With Colorectal Cancer and Predicts Worse Prognosis

Previous studies have shown that the presence of perineural invasion (PNI) is associated with a significantly worse prognosis in colorectal cancer (CRC) patients. In this study, we performed a detailed analysis of the diversity of extracellular vesicles (EV) between NPNI (non-PNI) and PNI using quantitative proteomics and aim to investigate the mechanisms underlying PNI in colorectal cancer. Quantitative proteomics technology was used to identify the proteome of serum-purified EVs from CRC patients with and without PNI (PNI and non-PNI (NPNI) groups, respectively) and healthy volunteers. Mass spectrometry data were verified by ELISA and Western blot analyses. The proteomic profile of serum EVs from the PNI group differed from that of those in the NPNI group. Serum-derived EVs from the PNI promoted more significant cellular mobility than EVs derived from the NPNI group. EV stratifin (SFN) expression levels demonstrated an area under the receiver operating characteristic curve values of 0.84 for discriminating patients with PNI from NPNI patients. Moreover, EV SFN expression levels were an independent predictor of CRC prognosis. In this study, we identified SFN as a potential biomarker for the diagnosis of PNI in stage II CRC patients.

Prognostic Significance of Perineural Invasion in Patients with Stage II/III Gastric Cancer Undergoing Radical Surgery

The prognostic significance of perineural invasion in patients with gastric cancer (GC) is controversial. This study aimed to determine the prognostic value of perineural invasion in patients with stage II/III GC undergoing radical surgery. A total of 1913 patients with stage II/III GC who underwent curative resection between 1994 and 2015 were recruited. Clinicopathological factors, tumor recurrence patterns, disease-free survival, and cancer-specific survival were compared in terms of perineural invasion. The prognostic factors of disease-free survival and cancer-specific survival were determined using univariate and multivariate analyses. Perineural invasion was found in 57.1% of the patients. Age of <65 years, female sex, large tumor size, upper tumor location, total gastrectomy, advanced tumor invasion depth and nodal involvement, greater metastatic to examined lymph node ratio, undifferentiated tumor, and presence of lymphatic or vascular invasion were significantly associated with perineural invasion. The patients with perineural invasion had higher locoregional/peritoneal recurrence rates than those without. Perineural invasion was independently associated with disease-free survival and cancer-specific survival. In conclusion, perineural invasion positivity is associated with aggressive tumor behaviors and higher locoregional/peritoneal recurrence rates in patients with stage II/III GC undergoing curative surgery. It is an independent unfavorable prognostic factor of disease recurrence and cancer-specific survival.

The Prognostic Reliability of Lymphovascular Invasion for Patients with T3N0 Colorectal Cancer in Adjuvant Chemotherapy Decision Making

Simple Summary

This retrospective analysis evaluated the prognostic implications of lymphovascular invasion (LVI) associated with adjuvant chemotherapy in 1634 patients with pT3N0 colorectal cancer. Extensive pathologic review and dual immunohistochemical (IHC) staining with CD31 and D2-40 were undertaken in a subset of 242 patients to determine the reliability of LVI as a prognostic factor. The diagnosis of LVI and PNI changed in 82 (33.9%) and 61 (25.2%) patients, respectively, after central pathologic review (mean follow up duration, 50 (1–114) months). Five-year recurrence-free survival (RFS) and overall survival (OS) rates were 92% and 94.8%, respectively. Before and after pathologic review, LVI was not associated with OS but was associated with RFS after reviewing patients with pT3N0 colorectal cancer. In this patient cohort, the prognostic implications of LVI may have been underrecognized when using hematoxylin and eosin staining slides only for pathologic diagnoses, possibly leading to low recurrence prediction rates.

Abstract

Lymphovascular invasion (LVI) is a high-risk feature guiding decision making for adjuvant chemotherapy. We evaluated the prognostic importance and reliability of LVI as an adjuvant chemotherapy indicator in 1634 patients with pT3N0 colorectal cancer treated with curative radical resection between 2012 and 2016. LVI and perineural invasion (PNI) were identified in 382 (23.5%) and 269 (16.5%) patients, respectively. In total, 772 patients received adjuvant chemotherapy. The five-year recurrence-free survival (RFS) and OS rates were 92% and 94.8%, respectively. Preoperative obstruction, PNI, and positive margins were significantly associated with RFS and OS; however, adjuvant chemotherapy and LVI were not. Pathologic slide central reviews of 242 patients using dual D2-40 and CD31 immunohistochemical staining was performed. In the review cohort, the diagnosis of LVI and PNI was changed in 82 (33.9%) and 61 (25.2%) patients, respectively. Reviewed LVI, encompassing small vessel invasion, lymphatic invasion, and large vessel invasion, was not an independent risk factor associated with OS but was related to RFS. The prognostic importance of LVI and adjuvant chemotherapy was not defined because LVI may be underrecognized in pathologic diagnoses using hematoxylin and eosin staining slides only, leading to low recurrence rate predictions. Using LVI as a guiding factor for adjuvant chemotherapy requires further consideration.

Identification of high-risk stage I colon and rectal cancer patients: a retrospective analysis of a large Japanese cohort

PURPOSE

Data regarding risk factors for recurrence in stage I colorectal cancer patients are limited. The aim of this study was to clarify the existence of a high-recurrence-risk population among stage I colorectal cancer patients.

METHODS

This analysis included 7,539 stage I colorectal cancer patients treated between 1997 and 2012 at 24 leading hospitals in Japan. Risk factors for time to recurrence were evaluated using a Cox proportional hazards model, and a high-risk group for recurrence was identified. Prognostic outcomes of high-risk stage I colorectal cancer patients were compared with those of low-risk stage I and stage II patients.

RESULTS

Multivariable analyses identified left-sided location (hazard ratio [HR]: 1.65, 95% confidence interval [CI]: 1.09-2.58), T2 tumors (HR: 1.80, 95% CI: 1.21-2.66), and lymphatic invasion (HR: 1.55, 95% CI: 1.05-2.28) as risk factors for recurrence in stage I colon cancer, and patients with these three risk factors were classified as high risk. For stage I rectal cancer, patients with poor differentiation (HR: 2.86, 95% CI: 1.21-5.69), T2 tumors (HR: 1.53, 95% CI: 1.07-2.23), and venous invasion (HR: 1.51, 95% CI: 1.08-2.13) were identified as high risk. The Kaplan-Meier analysis of cumulative recurrence rate and recurrence-free survival revealed that the high-risk stage I colorectal cancer patients have poorer clinical outcomes than the low-risk patients.

CONCLUSION

Although stage I colorectal cancer patients generally have a favorable prognosis after curative surgery, poorer prognosis was observed in high-risk stage I colorectal cancer patients than in low-risk patients.

Postoperative locoregional recurrence pattern and treatment management of stage pT4 sigmoid colon cancer: a retrospective cohort study

BACKGROUND

This study aimed to explore the pattern of locoregional recurrence after surgery in patients with non-metastatic stage pT4 sigmoid colon cancer and the role of adjuvant radiotherapy on survival.

METHODS

We retrospectively analyzed data from 208 patients who underwent surgery in our hospital. The patients were randomly divided into training and validation groups at a 1:1 ratio. Patients at high risk for locoregional recurrence were screened using Cox regression analysis. Based on the data of 2,886 patients in the Surveillance, Epidemiology, and End Results (SEER) database, the effect of adjuvant radiotherapy on overall survival (OS) and cancer-specific survival (CSS) was evaluated by Kaplan-Meier curves.

RESULTS

Of the 208 patients, 57 (27.4%) presented with locoregional recurrences (14 anastomotic and 43 abdominal or pelvic lymph node recurrences). Multivariate analysis showed that serum CEA, differentiation, lymph node dissection number, and N stage were independent predictors of locoregional recurrence-free survival (all p < 0.05). A risk-stratification model was constructed, and a total score of ≥ 6.5 points was considered the high-risk group for locoregional recurrence. Both the training and validation sets presented that the model had a good predictive ability (area under the curve = 0.828 and 0.724, respectively). Analysis of SEER data revealed that adjuvant radiotherapy significantly prolonged OS and CSS in the high-risk population (all p < 0.05, vs. no radiotherapy).

CONCLUSIONS

Patients with a total risk score of 6.5 or more had a high likelihood of locoregional recurrence, and perhaps adjuvant radiotherapy could improve their survival.

Limitations of Nerve Fiber Density as a Prognostic Marker in Predicting Oncological Outcomes in Hepatocellular Carcinoma

It has been shown that the presence and density of nerve fibers (NFs; NFD) in the tumor microenvironment (TME) may play an important prognostic role in predicting long-term oncological outcomes in various malignancies. However, the role of NFD in the prognosis of hepatocellular carcinoma (HCC) is yet to be explored. To this end, we aimed to investigate the impact of NFs on oncological outcomes in a large European single-center cohort of HCC patients. In total, 153 HCC patients who underwent partial hepatectomy in a curative-intent setting between 2010 and 2021 at our university hospital were included in this study. Group comparisons between patients with and without NFs were conducted and the association of recurrence-free survival (RFS) and overall survival (OS) with the presence of NFs and other clinico-pathological variables were determined by univariate and multivariable Cox regression models. Patients with NFs in the TME presented with a median OS of 66 months (95% CI: 30−102) compared to 42 months (95% CI: 20−63) for patients without NFs (p = 0.804 log-rank). Further, RFS was 26 months (95% CI: 12−40) for patients with NFs compared to 18 months (95% CI: 9−27) for patients without NFs (p = 0.666 log-rank). In a subgroup analysis, patients with NFD ≤ 5 showed a median OS of 54 months (95% CI: 11−97) compared to 48 months (95% CI: 0−106) for the group of patients with NFD > 5 (p = 0.787 log-rank). Correspondingly, the RFS was 26 months (95% CI: 10−42) in patients with NFD ≤ 5 and 29 months (95% CI: 14−44) for the subcohort with NFD > 5 (p = 0.421 log-rank). Further, group comparisons showed no clinico-pathological differences between patients with NFs (n = 76) and without NFs (n = 77) and NFs were not associated with OS (p = 0.806) and RFS (p = 0.322) in our Cox regression models. In contrast to observations in various malignancies, NFs in the TME and NFD are not associated with long-term oncological outcomes in HCC patients undergoing surgery.

Preoperative Prediction of Perineural Invasion Status of Rectal Cancer Based on Radiomics Nomogram of Multiparametric Magnetic Resonance Imaging

Objectives

To compare the predictive performance of different radiomics signatures from multiparametric magnetic resonance imaging (mpMRI), including four sequences when used individually or combined, and to establish and validate an optimal nomogram for predicting perineural invasion (PNI) in rectal cancer (RC) patients.

Methods

Our retrospective study included 279 RC patients without preoperative antitumor therapy (194 in the training dataset and 85 in the test dataset) who underwent preoperative mpMRI scan between January 2017 and January 2021. Among them, 72 cases were PNI-positive. Then, clinical and radiological variables were collected, including carcinoembryonic antigen (CEA), radiological tumour stage (T_1-4), lymph node stage (N_0-2) and so on. Quantitative radiomics features were extracted and selected from oblique axial T₂-weighted imaging (T₂WI), T₁-weighted imaging (T₁WI), apparent diffusion coefficient (ADC), and enhanced T₁WI (T₁CE) sequences. The clinical model was constructed by integrating the final selected clinical and radiological variables. The radiomics signatures included four single-sequence signatures and one fusion signature were built using the respective remaining optimized features. And the nomogram was constructed based on the independent predictors by using multivariable logistic regression. The area under curve (AUC), DeLong test, calibration curve, and decision curve analysis (DCA) were used to evaluate the performance.

Results

Ultimately, 20 radiomics features were retained from the four sequences—T₁WI (n = 4), T₂WI (n = 5), ADC (n = 5), and T₁CE (n = 6)—to construct four single-sequence radiomics signatures and one fusion radiomics signature. The fusion radiomics signature performed better than four single-sequence radiomics signatures and clinical model (AUCs of 0.835 and 0.773 vs. 0.680-0.737 and 0.666-0.709 in the training and test datasets, respectively). The nomogram constructed by incorporating CEA, tumour stage and rad-score performed best, with AUCs of 0.869 and 0.864 in the training and test datasets, respectively. Delong test showed that the nomogram was significantly different from the clinical model and four single-sequence radiomics signatures (P < 0.05). Moreover, calibration curves demonstrated good agreement, and DCA highlighted benefits of the nomogram.

Conclusions

The comprehensive nomogram can preoperatively and noninvasively predict PNI status, provide a convenient and practical tool for treatment strategy, and help optimize individualized clinical decision-making in RC patients.

Perineural invasion is a prognostic factor in stage II colorectal cancer but not a treatment indicator for traditional chemotherapy: a retrospective cohort study

BACKGROUND

Perineural invasion (PNI) is considered a risk factor of survival but does not yet inform treatment decisions, and has not been studied separately in stage II colorectal cancer (CRC) patients whose postoperative traditional chemotherapy is controversial. This cohort study aimed to assess the association of PNI with basic clinicopathological features and patient outcomes after curative resection and the effects of PNI on responses to adjuvant chemotherapy in stage II CRC.

METHODS

The clinical data of 371 stage II CRC patients who underwent curative-intent surgery at the National Cancer Center/Cancer Hospital in 2014 were retrospectively reviewed. The adjuvant chemotherapy data were acquired from follow-up information. PNI status was examined, and the overall survival (OS) and disease-free survival (DFS) rates were analyzed.

RESULTS

PNI was detected in 82 of the 371 patients (22.1%) and was closely correlated with preoperative serum carcinoembryonic antigen (CEA) levels (P=0.030), gross tumor type (P=0.010), tumor differentiation (P=0.010), p stage (P<0.001), and extramural vascular invasion (EMVI) (P<0.001). The median follow-up time was 71 months. The 5-year OS was 84.1% and 96.5% (P<0.001), and the 5-year DFS was 75.6% and 91.3% (P<0.001) for PNI-positive (+) and PNI-negative (-) patients, respectively. The multivariate regression analyses identified PNI as an independent negative prognostic factor for DFS [hazard ratio (HR): 2.95; 95% confidence interval (CI), 1.546-5.626; P=0.001] and OS (HR: 3.966; 95% CI, 1.642-9.575; P=0.002). Among PNI (+) patients, DFS and OS were positively correlated with CEA levels (P=0.005 and P=0.004, respectively). Postoperative chemotherapy failed to improve DFS (P=0.480 and P=0.267, respectively) and OS (P=0.940 and P=0.077, respectively) regardless of whether the patients were PNI positive or not.

CONCLUSIONS

In stage II CRC patients, PNI was a poor independent predictor for DFS and OS. Among PNI (+) patients, CEA levels were positively correlated with DFS and OS. Traditional postoperative adjuvant chemotherapy does not improve outcomes of PNI (+) patients. Therefore, as to the active role of PNI and vacancy for treatment in allusion to PNI, follow-up of PNI (+) patients with elevated CEA level should be strengthened and further research on drug conducted on PNI deserve to be carried on.

Identification of Predictive Factors for Lymph Node Metastasis in pT1 Stage Colorectal Cancer Patients: A Retrospective Analysis Based on the Population Database

Objective: The purpose of this study was to identify predictive factors for lymph node metastasis (LNM) in pT1 stage colorectal cancer (CRC) patients. Methods: From the Surveillance, Epidemiology, and End Results (SEER) database, 2,697 consecutive pT1 stage patients who underwent surgical resection were retrospectively reviewed. Predictive factors for LNM were identified by the univariate and multivariate logistic regression analysis. The Kaplan-Meier curves and multivariate Cox regression analysis were used to evaluate the relationships between LNM and overall survival (OS) as well as cancer specific survival (CSS) of pT1 stage CRC patients. Results: The prevalence of LNM in pT1 stage CRC patients was 15.2% (410/2,697). Patient age <60 years (OR:1.869, 95% CI: 1.505-2.321, p < 0.001), poorly differentiated or mucinous or signet ring cell adenocarcinoma (OR:2.075, 95% CI: 1.584-2.717, p < 0.001), elevated carcinoembryonic antigen (CEA) level (OR:1.343, 95% CI: 1.022-1.763, p = 0.033) and perineural invasion (PNI) (OR:6.212, 95% CI: 3.502-11.017, p < 0.001) were significantly associated with LNM in pT1 stage patients. The survival analysis demonstrated that pT1 stage patients with LNM had a worse OS (5-year OS: 82.2% vs 88.7%, p = 0.020) and CSS (5-year CSS: 74.9% vs 81.5%, p = 0.041) than those without lymph node metastasis. Lymph node metastasis was an independent predictor of poor OS (HR: 1.543, 95% CI: 1.156-2.060, p = 0.003) and CSS (HR: 1.614, 95% CI: 1.121-2.324, p = 0.010) for pT1 stage colorectal cancer patients. Conclusion: Age, differentiation type, CEA level and perineural invasion were independent predictive factors for LNM in pT1 stage CRC patients. These findings might provide further risk stratification for pT1 stage patients and help clinicians identify high-risk individuals.

The importance of MRI for rectal cancer evaluation

Magnetic resonance imaging (MRI) has gained increasing importance in the management of rectal cancer over the last two decades. The role of MRI in patients with rectal cancer has expanded beyond the tumor-node-metastasis (TNM) system in both staging and restaging scenarios and has contributed to identifying "high" and "low" risk features that can be used to tailor and personalize patient treatment; for instance, selecting the patients for neoadjuvant chemoradiation (NCRT) before the total mesorectal excision (TME) surgery based on risk of recurrence. Among those features, the status of the circumferential resection margin (CRM), extramural vascular invasion (EMVI), and tumor deposits (TD) have stood out. Moreover, MRI also has played a role in surgical planning, especially when the tumor is located in the low rectum, when the relationship between tumor and the anal canal is important to choose the best surgical approach, and in cases of locally advanced or recurrent tumors invading adjacent pelvic organs that may require more complex surgeries such as pelvic exenteration. As approaches using organ preservation emerge, including transanal local excision and "watch-and-wait", MRI may help in the patient selection for those treatments, follow up, and detection of tumor regrowth. Additionally, potential MRI-based prognostic and predictive biomarkers, such as quantitative and semi-quantitative metrics derived from functional sequences like diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE), and radiomics, are under investigation. This review provides an overview of the current role of MRI in rectal cancer in staging and restaging and highlights the main areas under investigation and future perspectives.

Dataset for Pathology Reporting of Colorectal Cancer: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

OBJECTIVE

The aim of this study to describe a new international dataset for pathology reporting of colorectal cancer surgical specimens, produced under the auspices of the International Collaboration on Cancer Reporting (ICCR).

BACKGROUND

Quality of pathology reporting and mutual understanding between colorectal surgeon, pathologist and oncologist are vital to patient management. Some pathology parameters are prone to variable interpretation, resulting in differing positions adopted by existing national datasets.

METHODS

The ICCR, a global alliance of major pathology institutions with links to international cancer organizations, has developed and ratified a rigorous and efficient process for the development of evidence-based, structured datasets for pathology reporting of common cancers. Here we describe the production of a dataset for colorectal cancer resection specimens by a multidisciplinary panel of internationally recognized experts.

RESULTS

The agreed dataset comprises eighteen core (essential) and seven non-core (recommended) elements identified from a review of current evidence. Areas of contention are addressed, some highly relevant to surgical practice, with the aim of standardizing multidisciplinary discussion. The summation of all core elements is considered to be the minimum reporting standard for individual cases. Commentary is provided, explaining each element's clinical relevance, definitions to be applied where appropriate for the agreed list of value options and the rationale for considering the element as core or non-core.

CONCLUSIONS

This first internationally agreed dataset for colorectal cancer pathology reporting promotes standardization of pathology reporting and enhanced clinicopathological communication. Widespread adoption will facilitate international comparisons, multinational clinical trials and help to improve the management of colorectal cancer globally.

Current Perspectives on the Importance of Pathological Features in Prognostication and Guidance of Adjuvant Chemotherapy in Colon Cancer

There is not a clear consensus on which pathological features and biomarkers are important in guiding prognosis and adjuvant therapy in colon cancer. The Pathology in Colon Cancer, Prognosis and Uptake of Adjuvant Therapy (PiCC UP) Australia and New Zealand questionnaire was distributed to colorectal surgeons, medical oncologists and pathologists after institutional board approval. The aim of this study was to understand current specialist attitudes towards pathological features in the prognostication of colon cancer and adjuvant therapy in stage II disease. A 5-scale Likert score was used to assess attitudes towards 23 pathological features for prognosis and 18 features for adjuvant therapy. Data were analysed using a rating scale and graded response model in item response theory (IRT) on STATA (Stata MP, version 15; StataCorp LP). One hundred and sixty-four specialists (45 oncologists, 86 surgeons and 33 pathologists) participated. Based on IRT modelling, the most important pathological features for prognosis in colon cancer were distant metastases, lymph node metastases and liver metastases. Other features seen as important were tumour rupture, involved margin, radial margin, CRM, lymphovascular invasion and grade of differentiation. Size of tumour, location, lymph node ratio and EGFR status were considered less important. The most important features in decision making for adjuvant therapy in stage II colon cancer were tumour rupture, lymphovascular invasion and microsatellite instability. BRAF status, size of tumour, location, tumour budding and tumour infiltrating lymphocytes were factored as lesser importance. Biomarkers such as CDX2, EGFR, KRAS and BRAF status present areas for further research to improve precision oncology. This study provides the most current status on the importance of pathological features in prognostication and recommendations for adjuvant therapy in Australia and New Zealand. Results of this nationwide study may be useful to help in guiding prognosis and adjuvant treatment in colon cancer.

Predicting response to neoadjuvant chemoradiotherapy in rectal cancer: from biomarkers to tumor models

Colorectal cancer (CRC) is a major contributor to cancer-associated morbidity worldwide and over one-third of CRC is located in the rectum. Neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection is commonly applied to treat locally advanced rectal cancer (LARC). In this review, we summarize current and novel concepts of neoadjuvant therapy for LARC such as total neoadjuvant therapy and describe how these developments impact treatment response. Moreover, as response to nCRT is highly divergent in rectal cancers, we discuss the role of potential predictive biomarkers. We review recent advances in biomarker discovery, from a clinical as well as a histopathological and molecular perspective. Furthermore, the role of emerging predictive biomarkers derived from the tumor environment such as immune cell composition and gut microbiome is presented. Finally, we describe how different tumor models such as patient-derived cancer organoids are used to identify novel predictive biomarkers for chemoradiotherapy (CRT) in rectal cancer.

Tumor Deposits and Perineural Invasion had Comparable Impacts on the Survival of Patients With Non-metastatic Colorectal Adenocarcinoma: A Population-Based Propensity Score Matching and Competing Risk Analysis

BACKGROUND

Both tumor deposits (TD) and perineural invasion (PNI) have been identified as risk factors for poor survival in patients with non-metastatic colorectal adenocarcinoma (CRC). However, the adverse impacts of TD and PNI on the survival of patients with non-metastatic CRC have not been compared.

METHOD

Patients with non-metastatic CRC with known TD and PNI status were selected from the Surveillance, Epidemiology, and End Results (SEER) database. First, bivariate logistic regression analysis was utilized to identify the factors associated with TD and PNI status. Then, patients were divided into four groups, according to TD and PNI status. Propensity score matching (PSM) was performed to balance the baseline covariates. The impact of TD and PNI on survival was assessed by analyzing overall survival (OS) and cancer-specific mortality (CSM) rates. OS was calculated by the Kaplan-Meier method with log-rank analysis. CSM was estimated by competing risk analysis using the Fine and Gray model.

RESULTS

A total of 70 689 patients with CRC met the inclusion and exclusion criteria. The positive rates of TD and PNI were 9.37% and 9.91%, respectively. For TD, the most important risk factor was N stage. With respect to PNI, the most significant factor was T stage. Tumor location, tumor size, differentiation grade, and serum CEA level were also correlated with TD and PNI status. After PSM, 1849 pairs were selected. Patients with TD⁺PNI⁺ status had the worst 5 year CSM and 5 year OS. In addition, the long-term survival outcomes of patients with TD⁺PNI^- and TD^-PNI⁺ status were comparable.

CONCLUSION

The adverse impacts of TD and PNI on the survival of patients with non-metastatic CRC were comparable. CRC patients with both TD and PNI positive had the worst survival outcome.

Application of artificial intelligence in a real-world research for predicting the risk of liver metastasis in T1 colorectal cancer

Background

Liver is the most common metastatic site of colorectal cancer (CRC) and liver metastasis (LM) determines subsequent treatment as well as prognosis of patients, especially in T1 patients. T1 CRC patients with LM are recommended to adopt surgery and systematic treatments rather than endoscopic therapy alone. Nevertheless, there is still no effective model to predict the risk of LM in T1 CRC patients. Hence, we aim to construct an accurate predictive model and an easy-to-use tool clinically.

Methods

We integrated two independent CRC cohorts from Surveillance Epidemiology and End Results database (SEER, training dataset) and Xijing hospital (testing dataset). Artificial intelligence (AI) and machine learning (ML) methods were adopted to establish the predictive model.

Results

A total of 16,785 and 326 T1 CRC patients from SEER database and Xijing hospital were incorporated respectively into the study. Every single ML model demonstrated great predictive capability, with an area under the curve (AUC) close to 0.95 and a stacking bagging model displaying the best performance (AUC = 0.9631). Expectedly, the stacking model exhibited a favorable discriminative ability and precisely screened out all eight LM cases from 326 T1 patients in the outer validation cohort. In the subgroup analysis, the stacking model also demonstrated a splendid predictive ability for patients with tumor size ranging from one to50mm (AUC = 0.956).

Conclusion

We successfully established an innovative and convenient AI model for predicting LM in T1 CRC patients, which was further verified in the external dataset. Ultimately, we designed a novel and easy-to-use decision tree, which only incorporated four fundamental parameters and could be successfully applied in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02424-7.

S100-stained perineural invasion is associated with worse prognosis in stage I/II colorectal cancer: Its possible association with immunosuppression in the tumor

Perineural invasion (PNI) is known as a poor prognostic factor in colorectal cancer (CRC). Although histopathological evaluation of PNI is usually conducted on hematoxylin and eosin (HE)-stained sections (HE-PNI), it remains controversial whether PNI can be precisely evaluated only by HE-staining, and its concise mechanisms causing worse prognosis remains elusive. In this study, we examined the impact of PNI evaluated by S-100-immunostaining (S100-PNI) on postoperative mortality in 279 consecutive CRC patients and further investigated its association with the tumor immune microenvironment. S100-PNI was present in 67.3% of tumors whereas HE-PNI was present in 18.5%. A 5-year cumulative incidence of death in the S100-PNI-positive group was significantly higher than that in the S100-PNI-negative group. Further statistical analyses revealed that S100-PNI was an independent prognostic factor of all-cause mortality in stage I/II but not in stage III/IV. Importantly, S100-PNI was associated with the altered tumor immune microenvironment. Infiltrating immune cell profiling revealed that stromal lymphocytic reaction, which was inversely correlated with postoperative mortality, was significantly reduced in S100-PNI-positive tumors compared to S100-PNI-negative tumors in stage I/II. These results indicated that S100-PNI was a poor prognostic factor in stage I/II CRC with possible association with immunosuppression in the tumor.

YBX1 Enhances Metastasis and Stemness by Transcriptionally Regulating MUC1 in Lung Adenocarcinoma

Abnormal expression of the transcription factor Y-box-binding protein-1 (YBX1) is associated with the proliferation, migration, aggressiveness, and stem-like properties of various cancers. These characteristics contribute to the tumorigenesis and metastasis of cancer. We found that the expression levels of Mucin-1 (MUC1) and YBX1 were positively correlated in lung adenocarcinoma cells and lung adenocarcinoma tissue. Our retrospective cohort study of 176 lung adenocarcinoma patients after surgery showed that low expression of both YBX1 and MUC1 was an independent predictor of the prognosis and recurrence of lung adenocarcinoma. In lung adenocarcinoma cells, the silencing/overexpression of YBX1 caused a simultaneous change in MUC1, and MUC1 overexpression partially reversed the decreased tumor cell migration, aggressiveness, and stemness caused by YBX1 silencing. Moreover, chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays proved that MUC1 was the downstream target of YBX1 and that YBX1 bound to the -1480~-1476 position in the promoter region of MUC1 to regulate its transcription. Furthermore, in mouse xenograft models and a lung cancer metastasis model, MUC1, which is downstream of YBX1, partially reversed the decreased number and size of tumors caused by YBX1 silencing. In conclusion, our findings indicated a novel mechanism by which YBX1 promotes the stemness and metastasis of lung adenocarcinoma by targeting MUC1 and provided a combination approach for diagnosis different from traditional single tumor biomarkers to predict patient prognosis and provide clinical treatment targets.

Worst Pattern of Perineural Invasion Redefines the Spatial Localization of Nerves in Oral Squamous Cell Carcinoma

As a key histopathological characteristic of tumor invasion, perineural invasion (PNI) assists tumor dissemination, whereas the current definition of PNI by dichotomy is not accurate and the prognostic value of PNI has not reached consensus. To define PNI status in each patient when mixed types of PNI occurred simultaneously, we here further subclassified the traditional PNI in 183 patients with oral squamous cell carcinoma (OSCC). The spatial localization of nerves in OSCC microenvironment was thoroughly evaluated and successfully concluded into four types of PNI: 0, tumor cells away from nerves; 1, tumor cells encircling nerves less than 33%; 2, tumor cells encircling nerves at least 33%; and 3, tumor cells infiltrating into nerve sheathes. Sequentially, patients were stratified by single and mixed types of PNI. Traditionally, types 0 and 1 were defined as PNI^-, while types 2 and 3 were PNI⁺, which predicted shorter survival time. When multiple types of PNI existed within one tumor, patients with higher score of PNI types tended to have a relatively worse prognosis. Therefore, to define the status of PNI more precisely, the new variable worst pattern of PNI (WPNI) was proposed, which was taken as the highest score of PNI types present in each patient no matter how focal. Results showed that patients with WPNI 1 had longest survival time, and WPNI 2 correlated with better overall survival (p = 0.02), local-regional recurrence-free survival (p = 0.03), and distant metastasis-free survival (p = 0.046) than WPNI 3. Multivariate Cox analysis confirmed that only WPNI 3 could independently predict patients' prognosis, which could be explained by a more damaged immune response in WPNI 3 patients with less CD3⁺CD8⁺ T cells and CD19⁺ B cells. Conclusively, WPNI by trichotomy provide more meticulous and precise pathological information for tumor-nerve interactions in OSCC patients.

Pathological Features and Prognostication in Colorectal Cancer

The prognostication of colorectal cancer (CRC) has traditionally relied on staging as defined by the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications. However, clinically, there appears to be differences in survival patterns independent of stage, suggesting a complex interaction of stage, pathological features, and biomarkers playing a role in guiding prognosis, risk stratification, and guiding neoadjuvant and adjuvant therapies. Histological features such as tumour budding, perineural invasion, apical lymph node involvement, lymph node yield, lymph node ratio, and molecular features such as MSI, KRAS, BRAF, and CDX2 may assist in prognostication and optimising adjuvant treatment. This study provides a comprehensive review of the pathological features and biomarkers that are important in the prognostication and treatment of CRC. We review the importance of pathological features and biomarkers that may be important in colorectal cancer based on the current evidence in the literature.

Radiomics for predicting perineural invasion status in rectal cancer

BACKGROUND

Perineural invasion (PNI), as a key pathological feature of tumor spread, has emerged as an independent prognostic factor in patients with rectal cancer (RC). The preoperative stratification of RC patients according to PNI status is beneficial for individualized treatment and improved prognosis. However, the preoperative evaluation of PNI status is still challenging.

AIM

To establish a radiomics model for evaluating PNI status preoperatively in RC patients.

METHODS

This retrospective study enrolled 303 RC patients in a single institution from March 2018 to October 2019. These patients were classified as the training cohort (n = 242) and validation cohort (n = 61) at a ratio of 8:2. A large number of intra- and peritumoral radiomics features were extracted from portal venous phase images of computed tomography (CT). After deleting redundant features, we tested different feature selection (n = 6) and machine-learning (n = 14) methods to form 84 classifiers. The best performing classifier was then selected to establish Rad-score. Finally, the clinicoradiological model (combined model) was developed by combining Rad-score with clinical factors. These models for predicting PNI were compared using receiver operating characteristic curve (ROC) analysis and area under the ROC curve (AUC).

RESULTS

One hundred and forty-four of the 303 patients were eventually found to be PNI-positive. Clinical factors including CT-reported T stage (cT), N stage (cN), and carcinoembryonic antigen (CEA) level were independent risk factors for predicting PNI preoperatively. We established Rad-score by logistic regression analysis after selecting features with the L1-based method. The combined model was developed by combining Rad-score with cT, cN, and CEA. The combined model showed good performance to predict PNI status, with an AUC of 0.828 [95% confidence interval (CI): 0.774-0.873] in the training cohort and 0.801 (95%CI: 0.679-0.892) in the validation cohort. For comparison of the models, the combined model achieved a higher AUC than the clinical model (cT + cN + CEA) achieved (P < 0.001 in the training cohort, and P = 0.045 in the validation cohort).

CONCLUSION

The combined model incorporating Rad-score and clinical factors can provide an individualized evaluation of PNI status and help clinicians guide individualized treatment of RC patients.

Interobserver variation in the classification of tumor deposits in rectal cancer-is the use of histopathological characteristics the way to go?

The focus on lymph node metastases (LNM) as the most important prognostic marker in colorectal cancer (CRC) has been challenged by the finding that other types of locoregional spread, including tumor deposits (TDs), extramural venous invasion (EMVI), and perineural invasion (PNI), also have significant impact. However, there are concerns about interobserver variation when differentiating between these features. Therefore, this study analyzed interobserver agreement between pathologists when assessing routine tumor nodules based on TNM 8. Electronic slides of 50 tumor nodules that were not treated with neoadjuvant therapy were reviewed by 8 gastrointestinal pathologists. They were asked to classify each nodule as TD, LNM, EMVI, or PNI, and to list which histological discriminatory features were present. There was overall agreement of 73.5% (κ 0.38, 95%-CI 0.33–0.43) if a nodal versus non-nodal classification was used, and 52.2% (κ 0.27, 95%-CI 0.23–0.31) if EMVI and PNI were classified separately. The interobserver agreement varied significantly between discriminatory features from κ 0.64 (95%-CI 0.58–0.70) for roundness to κ 0.26 (95%-CI 0.12–0.41) for a lone arteriole sign, and the presence of discriminatory features did not always correlate with the final classification. Since extranodal pathways of spread are prognostically relevant, classification of tumor nodules is important. There is currently no evidence for the prognostic relevance of the origin of TD, and although some histopathological characteristics showed good interobserver agreement, these are often non-specific. To optimize interobserver agreement, we recommend a binary classification of nodal versus extranodal tumor nodules which is based on prognostic evidence and yields good overall agreement.

Predicting Colon Cancer-Specific Survival for the Asian Population Using National Cancer Registry Data from Taiwan

PURPOSE

Colon cancer is the third most incident and life-threatening cancer in Taiwan. A comprehensive survival prediction system would greatly benefit clinical practice in this area. This study was designed to develop an accurate prognostic model for colon cancer patients by using clinicopathological variables obtained from the Taiwan Cancer Registry database.

METHODS

We analyzed 20,218 colon cancer patients from the Taiwan Cancer Registry database, who were diagnosed between 2007 and 2015, were followed up until December 31, 2017, and had undergone curative surgery. We proposed two prognostic models, with different combinations of predictors. The first model used only traditional clinical features. The second model included several colon cancer site-specific factors (circumferential resection margin, perineural invasion, obstruction, and perforation), in addition to the traditional features. Both prediction models were developed by using a Cox proportional hazards model. Furthermore, we investigated whether race is a significant predictor of survival in colon cancer patients by using Model 1 on the Surveillance, Epidemiology, and End Results (SEER) cancer registry dataset.

RESULTS

The proposed models displayed a robust prediction performance (all Harrell's c-index >0.8). For both the calibration and validation steps, the differences between the predicted and observed mortality were mostly less than 5%.

CONCLUSIONS

The prediction model (Model 1) is an effective predictor of survival regardless of the ethnic background of patients and can potentially help to provide better prediction of colon cancer-specific survival outcomes, thus allowing physicians to improve treatment plans.

Clinicopathological Features of Stage I-III Colorectal Cancer Recurrence Over 5 Years After Radical Surgery Without Receiving Neoadjuvant Therapy: Evidence From a Large Sample Study

Late recurrence (5 or more years) after radical resection of colorectal cancer (CRC) is rare. This study aims to investigate the features of late recurrence in stage I-III CRC. A total of 9,754 stage I-III patients with CRC who underwent radical surgery without receiving neoadjuvant therapy, at the Fudan University Shanghai Cancer Center (FUSCC), were enrolled in this study. These patients were divided into three groups: early recurrence (3 months-2 years), intermediate recurrence (2-5 years), and late recurrence (over 5 years). The median duration of follow-up was 53.5 ± 30.1 months. A total of 2,341 (24.0%) patients developed recurrence. The late recurrence rate was 11.7%. Patients with a higher risk of late recurrence were more likely to be older, to be at the T4 stage, to have a higher degree of colon cancer, to have a lower frequency of signet ring cell carcinoma, to have fewer poorly differentiated tumors, to be at the early stage of CRC, along with less perineural and vascular invasions. Multivariate logistic regression analysis identified age, differentiation, T stage, N stage, perineural, and vascular invasions as independent factors for late recurrence. Late recurrent CRC has some distinctive characteristics. Although recurrence over 5 years after surgery is infrequent, an enhanced follow-up is still needed for the selected patients after 5 years.

Treatment and Outcomes of Colorectal Cancer in Armenia: A Real-World Experience From a Developing Country

PURPOSE

In Armenia, colorectal cancer (CRC) is one of the most frequently diagnosed cancers. It is in the third place by incidence. The aim of this study was to evaluate treatment and outcomes of CRC in Armenia during the last 9 years.

MATERIALS AND METHODS

For this retrospective hospital-based study, we have collected data from two main oncology centers in Armenia: National Oncology Center and “Muratsan” Hospital of Yerevan State Medical University. The information about patients with CRC who were treated at these two centers between January 1, 2010 and July 1, 2018 was collected from the medical records. Log-rank test and Kaplan-Meier curves were used for survival analysis. Prognostic factors were identified by Cox regression.

RESULTS

A total of 602 patients with CRC were involved in the final analysis. Median follow-up time was 37 months (range, 3-207 months). A total of 8.6% of patients had stage I, 32.9% stage II, 38.0% stage III, and 17.6% stage IV cancer; for 2.7% patients, the stage was unknown. The main independent prognostic factors for overall survival (OS) were tumor stage, grade, and histology. Adjuvant chemotherapy has been shown to improve survival in stage II colon cancer and stage III rectal but not in stage II rectal cancer. Radiotherapy did not yield survival improvement in stage II or III rectal cancer. Three- and 5-year OS rates were 62.9% and 51.8% for all stages combined and 79.7% and 68.5% for stages I-II, 62.5% and 48.4% for stage III, and 24.4% and 17% for stage IV respectively.

CONCLUSION

As seen from our results, our survival rates are lower than those of the developed world. Additional research is needed to identify the underlying reasons and to improve patients’ treatment and outcomes in Armenia.

Prognostic Value of Perineural Invasion in Oral Tongue Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

OBJECTIVES

A significant number of recently published research has outlined the contribution of perineural invasion (PNI) to clinical outcomes in oral tongue squamous cell carcinoma (OTSCC), but some results remain conflicting. This study aimed to determine whether patients with OTSCC with PNI have a worse prognosis than those without PNI.

MATERIALS AND METHODS

PubMed, Embase, and the Cochrane Library were queried for potentially eligible articles published up to December 2020. The primary outcomes were the hazard ratio (HR) for locoregional recurrence, overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS). The random-effect model was used in all analyses.

RESULTS

Seventeen studies (4445 patients) were included. Using adjusted HRs, the presence of PNI was associated with a higher risk of locoregional recurrence (HR=1.73, 95%CI: 1.07-2.79, P=0.025, I2 = 33.1%, Pheterogeneity=0.224), worse OS (HR=1.94, 95%CI: 1.39-2.72, P<0.001, I2 = 0.0%, Pheterogeneity=0.838), worse DFS (HR=2.13, 95%CI: 1.53-2.96, P<0.001, I2 = 48.4%, Pheterogeneity=0.071), and worse CSS (HR=1.93, 95%CI: 1.40-2.65, P<0.001, I2 = 25.5%, Pheterogeneity=0.251). PNI had an impact on locoregional recurrence in early-stage OTSCC but not in all stages, and on OS, DFS, and CSS in all-stage and early-stage OTSCC. The sensitivity analyses showed that the results were robust.

CONCLUSION

The presence of PNI significantly affects the locoregional recurrence and survival outcomes among patients with OTSCC.

Blockage of Cholinergic Signaling via Muscarinic Acetylcholine Receptor 3 Inhibits Tumor Growth in Human Colorectal Adenocarcinoma

Cholinergic signaling via the muscarinic M3 acetylcholine receptor (M3R) is involved in the development and progression of colorectal cancer (CRC). The present study aimed to analyze the blocking of M3R signaling in CRC using darifenacin, a selective M3R antagonist. Darifenacin effects were studied on HT-29 and SW480 CRC cells using MTT and BrdU assays, Western blotting and real time RT-PCR. In vivo, blocking of M3R was assessed in an orthotopic CRC xenograft BALB/c^nu/nu mouse model. M3R expression in clinical tumor specimens was studied by immunohistochemistry on a tissue microarray of 585 CRC patients. In vitro, darifenacin decreased tumor cell survival and proliferation in a dose-dependent manner. Acetylcholine-induced p38, ERK1/2 and Akt signaling, and MMP-1 mRNA expression were decreased by darifenacin, as well as matrigel invasion of tumor cells. In mice, darifenacin reduced primary tumor volume and weight (p < 0.05), as well as liver metastases, compared to controls. High expression scores of M3R were found on 89.2% of clinical CRC samples and correlated with infiltrative tumor border and non-mucinous histology (p < 0.05). In conclusion, darifenacin inhibited components of tumor growth and progression in vitro and reduced tumor growth in vivo. Its target, M3R, was expressed on the majority of CRC. Thus, repurposing darifenacin may be an attractive addition to systemic tumor therapy in CRC patients expressing M3R.

Loss of enteric neuronal Ndrg4 promotes colorectal cancer via increased release of Nid1 and Fbln2

The N-Myc Downstream-Regulated Gene 4 (NDRG4), a prominent biomarker for colorectal cancer (CRC), is specifically expressed by enteric neurons. Considering that nerves are important members of the tumor microenvironment, we here establish different Ndrg4 knockout (Ndrg4-/- ) CRC models and an indirect co-culture of primary enteric nervous system (ENS) cells and intestinal organoids to identify whether the ENS, via NDRG4, affects intestinal tumorigenesis. Linking immunostainings and gastrointestinal motility (GI) assays, we show that the absence of Ndrg4 does not trigger any functional or morphological GI abnormalities. However, combining in vivo, in vitro, and quantitative proteomics data, we uncover that Ndrg4 knockdown is associated with enlarged intestinal adenoma development and that organoid growth is boosted by the Ndrg4-/- ENS cell secretome, which is enriched for Nidogen-1 (Nid1) and Fibulin-2 (Fbln2). Moreover, NID1 and FBLN2 are expressed in enteric neurons, enhance migration capacities of CRC cells, and are enriched in human CRC secretomes. Hence, we provide evidence that the ENS, via loss of Ndrg4, is involved in colorectal pathogenesis and that ENS-derived Nidogen-1 and Fibulin-2 enhance colorectal carcinogenesis.

Prognostic analysis and beneficiary identification of adjuvant external beam radiotherapy for stage pT4b sigmoid colon cancer

The clinical efficacy of adjuvant radiotherapy in sigmoid colon cancer remains questioned. To evaluate the clinical efficacy of adjuvant external beam radiotherapy (EBRT) for patients with pathologic stage T4b sigmoid colon cancer. Patients with stage pT4b sigmoid colon cancer receiving adjuvant EBRT or not followed by surgery between 2004 and 2016 were extracted from the Surveillance, Epidemiology, and End Results database. Analysis of overall survival (OS) was performed using Kaplan-Meier curves and prognostic factors were identified using Cox proportional hazards regression models with 95% confidence intervals within the entire cohort. A risk-stratification system was then developed based on the β regression coefficient. Among 2073 patients, 284 (13.7%) underwent adjuvant EBRT. The median OS in the group receiving adjuvant EBRT was significantly longer than that in the non-radiotherapy group (p < 0.001). Age, serum carcinoembryonic antigen (CEA) level, perineural invasion, lymph node dissection (LND) number, and adjuvant EBRT were independent factors associated with OS. A risk-stratification system was generated, which showed that low-risk patients had a higher 5-year survival rate than high-risk patients (75.6% vs. 42.3%, p < 0.001). Adjuvant EBRT significantly prolonged the 5-year survival rate of high-risk patients (62.6% vs. 38.3%, p = 0.009) but showed no survival benefit among low-risk patients (87.7% vs. 73.2%, p = 0.100). Our risk-stratification model comprising age, serum CEA, perineural invasion, and LND number predicted the outcomes of patients with stage pT4b sigmoid colon cancer based on which subgroup of high-risk patients should receive adjuvant EBRT.

A clinical-radiomics model incorporating T2-weighted and diffusion-weighted magnetic resonance images predicts the existence of lymphovascular invasion / perineural invasion in patients with colorectal cancer

PURPOSE

Lymphovascular invasion (LVI) and perineural invasion (PNI) are independent prognostic factors in patients with colorectal cancer (CRC). In this study, we aimed to develop and validate a preoperative predictive model based on high-throughput radiomic features and clinical factors for accurate prediction of LVI/PNI in these patients.

METHODS

Two hundred and sixty-three patients who underwent colorectal resection for histologically confirmed CRC between 1 February 2011 and 30 June 2020 were retrospectively enrolled. Between 1 February 2011 and 30 September 2018, 213 patients were randomly divided into a training cohort (n = 149) and a validation cohort (n = 64) by a ratio of 7:3. We used a 10000-iteration bootstrap analysis to estimate the prediction error and confidence interval for two cohorts. The independent test cohort consisted of 50 patients between 1 October 2018 and 30 June 2020. Regions of interest (ROIs) were manually delineated in high-resolution T2-weighted and diffusion-weighted images using ITK-SNAP software on each CRC tumor slice. In total, 3356 radiomic features were extracted from each ROI. Next, we used the maximum relevance minimum redundancy and least absolute shrinkage and selection operator algorithms to select the strongest of these features to establish a clinical-radiomics model for predicting LVI/PNI. Receiver-operating characteristic and calibration curves were then plotted to evaluate the predictive performance of the model in the training, validation, and independent test cohorts.

RESULTS

A multiparametric clinical-radiomics model combining MRI-reported extramural vascular invasion (EMVI) status and a Radiomics score for the LVI/PNI estimation was established. This model had significant predictive power in the training cohort (area under the curve [AUC] 0.91; 95% confidence interval [CI]: 0.85-0.97), validation cohort (AUC: 0.88; 95% CI: 0.79-89), and independent test cohorts (AUC 0.83, 95% CI 0.72-0.95). The model performed well in the independent test cohort with sensitivity of 0.818, specificity of 0.714, and accuracy of 0.760. Calibration curve and decision curve analysis demonstrated clinical benefits.

CONCLUSION

Multiparametric clinical-radiomics models can accurately predict LVI/PNI in patients with CRC. Our model has predictive ability that should improve preoperative diagnostic performance and allow more individualized treatment decisions.

High resolution MRI-based radiomic nomogram in predicting perineural invasion in rectal cancer

BACKGROUND

To establish and validate a high-resolution magnetic resonance imaging (HRMRI)-based radiomic nomogram for prediction of preoperative perineural invasion (PNI) of rectal cancer (RC).

METHODS

Our retrospective study included 140 subjects with RC (99 in the training cohort and 41 in the validation cohort) who underwent a preoperative HRMRI scan between December 2016 and December 2019. All subjects underwent radical surgery, and then PNI status was evaluated by a qualified pathologist. A total of 396 radiomic features were extracted from oblique axial T2 weighted images, and optimal features were selected to construct a radiomic signature. A combined nomogram was established by incorporating the radiomic signature, HRMRI findings, and clinical risk factors selected by using multivariable logistic regression.

RESULTS

The predictive nomogram of PNI included a radiomic signature, and MRI-reported tumor stage (mT-stage). Clinical risk factors failed to increase the predictive value. Favorable discrimination was achieved between PNI-positive and PNI-negative groups using the radiomic nomogram. The area under the curve (AUC) was 0.81 (95% confidence interval [CI], 0.71-0.91) in the training cohort and 0.75 (95% CI, 0.58-0.92) in the validation cohort. Moreover, our result highlighted that the radiomic nomogram was clinically beneficial, as evidenced by a decision curve analysis.

CONCLUSIONS

HRMRI-based radiomic nomogram could be helpful in the prediction of preoperative PNI in RC patients.

Preoperative prediction of perineural invasion with multi-modality radiomics in rectal cancer

Perineural invasion (PNI) as a grossly underreported independent risk predictor in rectal cancer is hard to identify preoperatively. We aim to predict PNI status in rectal cancer using multi-modality radiomics. In total, 396 radiomics features were extracted from T2-weighted images (T2WIs), diffusion-weighted images (DWIs), and portal venous phase of contrast-enhanced CT (CE-CT) respectively of 94 consecutive patients with histologically confirmed rectal cancer. T2WI score, DWI score, and CT score were calculated via the radiomics features selection and optimization. Discrimination, calibration, and clinical benefit ability were used to evaluate the performance of the radiomics scores in both training and testing datasets. CT score and T2WI score were independent risk predictors [CT score, OR (95% CI) = 4.218 (1.070-16.620); T2WI score, OR (95% CI) = 105.721 (3.091-3615.790)]. The concise score which combined CT score and T2WI score, showed the best performance [training dataset, AUC (95% CI) = 0.906 (0.833-0.979); testing dataset, AUC (95% CI) = 0.884 (0.761-1.000)] and good calibration (P > 0.05 in the Hosmer-Lemeshow test for the training and testing datasets). Decision curve analysis showed that the multi-modality radiomics nomogram had a higher clinical net benefit. The multi-modality radiomics score could be used to preoperatively assess PNI status in rectal cancer.

The enteric nervous system in gastrointestinal disease etiology

A highly conserved but convoluted network of neurons and glial cells, the enteric nervous system (ENS), is positioned along the wall of the gut to coordinate digestive processes and gastrointestinal homeostasis. Because ENS components are in charge of the autonomous regulation of gut function, it is inevitable that their dysfunction is central to the pathophysiology and symptom generation of gastrointestinal disease. While for neurodevelopmental disorders such as Hirschsprung, ENS pathogenesis appears to be clear-cut, the role for impaired ENS activity in the etiology of other gastrointestinal disorders is less established and is often deemed secondary to other insults like intestinal inflammation. However, mounting experimental evidence in recent years indicates that gastrointestinal homeostasis hinges on multifaceted connections between the ENS, and other cellular networks such as the intestinal epithelium, the immune system, and the intestinal microbiome. Derangement of these interactions could underlie gastrointestinal disease onset and elicit variable degrees of abnormal gut function, pinpointing, perhaps unexpectedly, the ENS as a diligent participant in idiopathic but also in inflammatory and cancerous diseases of the gut. In this review, we discuss the latest evidence on the role of the ENS in the pathogenesis of enteric neuropathies, disorders of gut-brain interaction, inflammatory bowel diseases, and colorectal cancer.

Does preoperative stent positioning in obstructive left sided colon cancer increase the risk of perineural invasion?

Colonic stenting as a bridge to surgery has been shown to be a safe and effective treatment for left-sided malignant colonic obstruction depending on local expertise. However, concerns still exist regarding its oncological safety. In particular, several reports showed an increased prevalence of perineural tumor invasion following stent placement. Since perineural invasion negatively affects oncological outcomes, the present study sought to evaluate this controversial association. We retrospectively reviewed 114 patients presenting with left-side obstructing colon cancer over a 10-year period. The relationship between perineural invasion and colonic stenting was analyzed using univariate and multivariate analyses. Perineural invasion was found to be strongly associated with pathological features, including TNM stage, (p < 0.001), poor differentiation (p = 0.002), vascular invasion (p < 0.001), lymphatic invasion (p < 0.001), whereas no significant association with preoperative stenting was observed (p = 0.918) after performing univariate analysis. In the multivariate model, only TNM stage III-IV (OR: 6.810, 95% CI 1.972-23.518, p = 0.002) and venous invasion (OR: 5.325, 95% CI 1.911-14.840, p = 0.001) were independently associated with perineural invasion. The results of this study suggest no association between preoperative colonic stenting and perineural invasion.