Challenges in the management of stage II colon cancer

Tumor aggression-defense index-a novel indicator to predicts recurrence and survival in stage II-III colorectal cancer

BACKGROUND

Although the TNM staging system plays a critical role in guiding adjuvant chemotherapy for colorectal cancer (CRC), its precision for risk stratification in stage II and III CRC patients with proficient DNA mismatch repair (pMMR) remains limited. Therefore, precise predictive models and research on postoperative treatments are crucial for enhancing patient survival and improving quality of life.

METHODS

This retrospective study analyzed 1051 pMMR CRC patients who underwent radical resection and were randomly assigned to training (n = 736) and validation (n = 315) groups. Immunohistochemistry and hematoxylin and eosin staining were utilized to evaluate regulatory-Immunoscore (RIS), tertiary lymphoid structures (TLS), and tumor budding (TB). The Tumor Aggression-Defense Index (TADI) was derived through a multi-factor COX regression model. Subgroup analysis demonstrated potential of TADI in guiding personalized adjuvant therapy for stage II and III CRC.

RESULTS

Univariate and multivariate Cox analysis indicated that TADI was an independent prognostic indicator. Among stage II CRC, chemotherapy was significantly correlated with improved recurrence times in individuals with intermediate (95% CI 0.19-0.59, P < 0.001) and high (95% CI 0.36-0.95, P = 0.031) TADI. In stage III CRC receiving adjuvant chemotherapy, a duration of 3 months or longer was notably associated with a prolonged time to recurrence in those with high TADI (95% CI 0.40-0.98, P = 0.041) compared to durations of less than 3 months.

CONCLUSION

The TADI serves as an effective parameter for predicting the survival outcomes of stage I-III pMMR CRC patients and guiding precision treatment strategies.

The Transcriptional Landscape of Coding and Noncoding RNAs in Recurrent and Nonrecurrent Colon Cancer

A number of patients with colon cancer with local or local advanced disease suffer from recurrence and there is an urgent need for better prognostic biomarkers in this setting. Here, the transcriptomic landscape of mRNAs, long noncoding RNAs, snRNAs, small nucleolar RNAs (snoRNAs), small Cajal body-specific RNAs, pseudogenes, and circular RNAs, as well as RNAs denoted as miscellaneous RNAs, was profiled by total RNA sequencing. In addition to well-known coding and noncoding RNAs, differential expression analysis also uncovered transcripts that have not been implicated previously in colon cancer, such as RNA5SP149, RNU4-2, and SNORD3A. Moreover, there was a profound global up-regulation of snRNA pseudogenes, snoRNAs, and rRNA pseudogenes in more advanced tumors. A global down-regulation of circular RNAs in tumors relative to normal tissues was observed, although only a few were expressed differentially between tumor stages. Many previously undescribed transcripts, including RNU6-620P, RNU2-20P, VTRNA1-3, and RNA5SP60, indicated strong prognostic biomarker potential in receiver operating characteristics analyses. In summary, this study unveiled numerous differentially expressed RNAs across various classes between recurrent and nonrecurrent colon cancer. Notably, there was a significant global up-regulation of snRNA pseudogenes, snoRNAs, and rRNA pseudogenes in advanced tumors. Many of these newly discovered candidates demonstrate a strong prognostic potential for stage II colon cancer.

A comparative analysis of different reduced-port laparoscopic surgical procedures after non-curative endoscopic resection for early colorectal cancer

Introduction

Surgery serves as a salvage procedure for non-curative resection of early-stage colorectal cancer under endoscopy. A standard method for performing additional surgery after endoscopic submucosal dissection (ESD) for early colorectal cancer has yet to be established.

Aim

To enhance the understanding of different surgical outcomes by discussing additional treatment strategies following non-complete curative endoscopic resection of early colorectal cancer.

Material and methods

This retrospective study included 88 patients who were divided into three groups based on the surgical approach: conventional laparoscopic surgery (CLS), single-incision plus one-port laparoscopic surgery (SILS+1), and three-port laparoscopic surgery combined with natural orifice specimen extraction surgery (three-port NOSES). The study aimed to compare the surgical outcomes, safety, and postoperative recovery among these groups.

Results

The SILS+1 and three-port NOSES groups demonstrated comparable safety and efficacy to the CLS group in terms of blood loss, complications, number of lymph node dissections, and length of bowel resection. However, the SILS+1 and three-port NOSES groups had advantages in terms of incision length (7.11 ±0.38, 4.24 ±0.33, 3.16 ±0.22, p < 0.001), postoperative pain (4.000 [3.0,5.0], 3.500 [3.0,4.0], 3.000 [3.0,4.0]; p = 0.003), cosmetic result (4.000 [3.8,5.0], 7.000 [7.0,8.0], 7.000 [7.0,8.0]; p < 0.001), and hospital stay (8.000 [7.0,9.0], 7.000 [6.3,8.0.], 7.000 [6.3,8.0]; p = 0.035).

Conclusions

Different strategies of reduced-port laparoscopic surgery have been demonstrated to be effective and safe in additional surgery after non-curative ESD. These techniques have shown reduced pain and increased satisfaction among patients. Reduced-port laparoscopic surgery is expected to become the preferred treatment option for these patients.

A recurrence-predictive model based on eight genes and tumor mutational burden/microsatellite instability status in Stage II/III colorectal cancer

BACKGROUND

Although adjuvant chemotherapy (ACT) is widely used to treat patients with Stage II/III colorectal cancer (CRC), administering ACT to specific patients remains a challenge. The decision to ACT requires an accurate assessment of recurrence risk and absolute treatment benefit. However, the traditional TNM staging system does not accurately assess a patient's individual risk of recurrence.

METHODS

To identify recurrence risk-related genetic factors for Stage II/III CRC patients after radical surgery, we conducted an analysis of whole-exome sequencing of 47 patients with Stage II/III CRC who underwent radical surgery at five institutions. Patients were grouped into non-recurrence group (NR, n = 24, recurrence-free survival [RFS] > 5 years) and recurrence group (R, n = 23, RFS <2 years). The TCGA-COAD/READ cohort was employed as the validation dataset.

RESULTS

A recurrence-predictive model (G8plus score) based on eight gene (CUL9, PCDHA12, HECTD3, DCX, SMARCA2, FAM193A, AATK, and SORCS2) mutations and tumor mutation burden/microsatellite instability (TMB/MSI) status was constructed, with 97.87% accuracy in our data and 100% negative predictive value in the TCGA-COAD/READ cohort. For the TCGA-COAD/READ cohort, the G8plus-high group had better RFS (HR = 0.22, p = 0.024); the G8plus-high tumors had significantly more infiltrated immune cell types, higher tertiary lymphoid structure signature scores, and higher immunological signature scores. The G8plus score was also a predict biomarker for immunotherapeutic in advanced CRC in the PUCH cohort.

CONCLUSIONS

In conclusion, the G8plus score is a powerful biomarker for predicting the risk of recurrence in patients with stage II/III CRC. It can be used to stratify patients who benefit from ACT and immunotherapy.

The effect of adjuvant chemotherapy on survival in node negative colorectal cancer with or without perineural invasion: a systematic review and meta-analysis

Purpose

It was aimed at assessing the benefits of adjuvant chemotherapy (ACT) for patients with node-negative colorectal cancer (CRC) either with or without perineural invasion (PNI).

Methods

We systematically searched PubMed, Cochrane Library, Embase, and Web of Science from database inception through October 1, 2023. Survival outcomes were analyzed using hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). The methodological quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS). Heterogeneity for the descriptive meta-analyses was quantified using the I2 statistic.

Results

Ten studies included in this review. ACT improved overall survival (OS) (HR 0.52, 95% CI 0.40-0.69) and disease-free survival (DFS) (HR 0.53, 95% CI 0.35-0.82) in PNI + patients but did not affect DFS (HR 1.13, 95% CI 0.72-1.77) in PNI- patients. A disease-specific survival (DSS) benefit with chemotherapy was observed in PNI + (HR 0.76, 95% CI 0.58-0.99) and PNI- patients (HR 0.76, 95% CI 0.57-1.00). And PNI decreased DFS (HR 1.94, 95% CI 1.52-2.47) and OS (HR 1.75, 95% CI 0.96-3.17) in node-negative CRC.

Conclusions

In conclusion, chemotherapy appears most beneficial for survival outcomes in node-negative patients with PNI, but may also confer some advantage in those without PNI.

Systematic Review Registration

Identifier INPLASY2021120103.

The Prognostic Value of Micropapillary Pattern in Colon Cancer and Its Role as a High-Risk Feature in Patients With Stage II Disease

BACKGROUND

The association of a micropapillary pattern with oncologic outcomes has not been fully studied in patients with colon cancer.

OBJECTIVE

We evaluated the prognostic value of a micropapillary pattern, especially for patients with stage II colon cancer.

DESIGN

A retrospective comparative cohort study using propensity score matching.

SETTING

This study was conducted at a single tertiary center.

PATIENTS

Patients with primary colon cancer undergoing curative resection from October 2013 to December 2017 were enrolled. Patients were grouped into micropapillary pattern positive or micropapillary pattern negative.

MAIN OUTCOME MEASUREMENTS

Disease-free survival and overall survival.

RESULTS

Of the eligible 2192 patients, 334 (15.2%) were with micropapillary pattern (+). After 1:2 propensity score matching, 668 patients with micropapillary pattern-negative status were selected. The micropapillary pattern-positive group showed significantly worse 3-year disease-free survival (77.6% vs 85.1%, p = 0.007). Three-year overall survival of micropapillary pattern-positive and micropapillary pattern-negative patients did not show a statistically significant difference (88.9% vs 90.4%, p = 0.480). In multivariable analysis, micropapillary pattern-positive was an independent risk factor for poor disease-free survival (HR 1.547, p = 0.008). In the subgroup analysis for 828 patients with stage II disease, 3-year disease-free survival deteriorated significantly in micropapillary pattern-positive patients (82.6% vs 93.0, p < 0.001). Three-year overall survival was 90.1% and 93.9% in patients positive and negative for micropapillary pattern, respectively ( p = 0.082). In the multivariable analysis for patients with stage II disease, micropapillary pattern-positive status was an independent risk factor for poor disease-free survival (HR 2.003, p = 0.031).

LIMITATIONS

Selection bias due to the retrospective nature of the study.

CONCLUSIONS

Micropapillary pattern-positive status may serve as an independent prognostic factor for colon cancer, especially for patients with stage II disease.

VALOR PRONSTICO DEL PATRN MICROPAPILAR Y SU PAPEL COMO CARACTERSTICA DE ALTO RIESGO EN PACIENTES CON CNCER DE COLON EN ESTADO II

ANTECEDENTES:La asociación del patrón micropapilar con los resultados oncológicos no ha sido completamente estudiada en pacientes con cáncer de colon.OBJETIVO:Evaluamos el valor pronóstico del patrón micropapilar, especialmente en pacientes con cáncer de colon en estadio II.DISEÑO:Estudio de cohortes comparativo y retrospectivo que utilize el emparejamiento por puntuación de propensiones.AJUSTE:Estudio realizado en un solo centro terciario.PACIENTES:Se incluyeron los pacientes con cáncer de colon primario sometidos a resección curativa desde octubre de 2013 hasta diciembre de 2017. Los pacientes se agruparon en patrón micropapilar positivo ( + ) o patrón micropapilar negativo ( - ).PRINCIPALES MEDIDAS DE RESULTADO:Sobrevida libre de enfermedad y la sobrevida global.RESULTADOS:De los 2192 pacientes elegibles, 334 (15,2%) tenían patrón micropapilar (+). Después de emparejar el puntaje de propensión 1:2, se seleccionaron 668 pacientes con patrón micropapilar (-). El grupo con patrón micropapilar (+) mostró una sobrevida libre de enfermedad significativamente inferior a los tres años (77,6% frente a 85,1%, p = 0,007). La sobrevida global a los tres años del patrón micropapilar (+) y del patrón micropapilar (-) no mostró una diferencia estadísticamente significativa (88,9 % frente a 90,4%, p = 0,480). En el análisis multivariable, el patrón micropapilar (+) fue un factor de riesgo independiente para una deficiente sobrevida libre de enfermedad (índice de riesgo 1,547, p = 0,008). En el análisis de subgrupos de 828 pacientes con enfermedad en estadio II, la sobrevida libre de enfermedad a los tres años se deterioró significativamente en los pacientes con patrón micropapilar (+) (82,6% frente a 93,0, p < 0,001). La sobrevida global a los tres años fué del 90,1% y del 93,9% en el patrón micropapilar (+) y el patrón micropapilar (-), respectivamente ( p = 0,082). En el análisis multivariable de los pacientes con enfermedad en estadio II, el patrón micropapilar (+) fue un factor de riesgo independiente para una sobrevida libre de enfermedad deficiente (índice de riesgo 2,003, p = 0,031).LIMITACIONES:Sesgo de selección debido a la naturaleza retrospectiva del estudio.CONCLUSIONES:El patrón micropapilar (+) sirve como factor pronóstico independiente para el cáncer de colon, especialmente para pacientes con enfermedad en estadio II. (Traducción-Dr. Xavier Delgadillo ).

Risk factors for postoperative recurrence in patients with stage II colorectal cancer

BACKGROUND

Recurrences are the main reasons for unfavorable outcomes for patients with stage II colorectal cancer (CRC). To obtain a clear understanding of the high-risk factors, further investigation is warranted. The present study aimed to analyze the risk factors associated with postoperative recurrence in patients with stage II CRC.

METHODS

Eligible patients with pathologically confirmed stage II CRC were enrolled in the study retrospectively based on a prospectively maintained database from April 2008 to March 2019. The Kaplan-Meier method were used to calculate the overall survival (OS) rate and the cumulative recurrence rate. Univariate and multivariable Cox regression analyses were performed to identify risk factors for recurrence.

RESULTS

There were 2515 patients included, of whom 233 (9.3%) developed local or distant recurrence. Recurrence was associated with a significantly worse 5-year OS (45.4% vs. 95.5%, p < 0.0001). The 5-year cumulative recurrence rate was 13.0% in patients with stage II CRC. On multivariable Cox analysis, tumor size (Hazard Ratio (HR) [95% confidence interval (CI)] = 1.79[1.38, 2.33]), preoperative carbohydrate antigen (CA) 125 level (HR [95% CI] = 1.78[1.17, 2.70]), preoperative CA 199 level (HR [95% CI] = 1.56[1.09, 2.22]), and ulcerating tumor (HR [95% CI] = 1.61[1.19, 2.17]) were found to be associated with postoperative recurrence. Adjuvant chemotherapy was associated with a lower cumulative recurrence rate in patients with these risk factors (p = 0.00096).

CONCLUSION

The tumor diameter, preoperative CA125 level, preoperative CA199 level, and an ulcerative tumor can predict postoperative recurrence in patients with stage II CRC, and postoperative chemotherapy could reduce the cumulative recurrence rate in patients with these high-risk factors.

Node-negative colon cancer: histological, molecular, and stromal features predicting disease recurrence

BACKGROUND

Within the group of node-negative colon cancer patients, presumed to have a good prognosis, a significant percentage of patients develops cancer-recurrence. Current high-risk features prove inadequate to select these particular high-risk patients. In the process of tailor-made care and shared decision-making the need to identify these patients grows. In this study we investigate the value of adding molecular markers and the tumour-stroma ratio (TSR) to conventional histological tumour staging methods to improve the selection of high risk patients.

METHODS

We retrospectively analysed 201 patients diagnosed with TNM-stage I-II colon cancer and treated by complete oncological resection between November 1st 2002 and December 31st 2012 at the Jeroen Bosch Hospital. Conventional histological tumour staging, BRAF mutations, KRAS mutations, MSI status and TSR were determined. Differences between groups based on TSR and mutation status, in disease free survival were analysed using Cox-Regression analyses.

RESULTS

Poorly differentiated histology (p = 0.002), high-TSR (p = 0.033), BRAF-mutation (p = 0.008) and MSI (p = 0.011) were identified as significant risk factors for cancer recurrence. The risk of recurrence increased in the presence of both a BRAF-mutation and high-TSR compared to the absence of both factors or presence of only one factor (HR = 3.66 BRAF-mt/TSR-low (p = 0.006), HR 2.82 BRAF-wt/TSR-high (p = 0.015), HR = 4.39 BRAF-mt/TSR-high (p = 0.023)). This was also seen in tumours with MSI and high-TSR (HR = 2.46 MSS/TSR-high (p = 0.041), HR = 3.31 MSI/TSR-high (p = 0.045).

CONCLUSION

Judging by the higher HR for the combination of the prognostic factors TSR and BRAF compared to the HRs of these prognostic factors individually, the prognostication for disease free survival can be improved by determining both TSR and BRAF instead of BRAF alone, as is done in current daily practise. In this study MSI also shows additional value to TSR in the prognostication of disease free survival. Adopting TSR into daily diagnostics will be of additional value next to currently used molecular markers in risk stratification of patients with node negative colon cancer and is therefore advised.

meth-SemiCancer: a cancer subtype classification framework via semi-supervised learning utilizing DNA methylation profiles

BACKGROUND

Identification of the cancer subtype plays a crucial role to provide an accurate diagnosis and proper treatment to improve the clinical outcomes of patients. Recent studies have shown that DNA methylation is one of the key factors for tumorigenesis and tumor growth, where the DNA methylation signatures have the potential to be utilized as cancer subtype-specific markers. However, due to the high dimensionality and the low number of DNA methylome cancer samples with the subtype information, still, to date, a cancer subtype classification method utilizing DNA methylome datasets has not been proposed.

RESULTS

In this paper, we present meth-SemiCancer, a semi-supervised cancer subtype classification framework based on DNA methylation profiles. The proposed model was first pre-trained based on the methylation datasets with the cancer subtype labels. After that, meth-SemiCancer generated the pseudo-subtypes for the cancer datasets without subtype information based on the model's prediction. Finally, fine-tuning was performed utilizing both the labeled and unlabeled datasets.

CONCLUSIONS

From the performance comparison with the standard machine learning-based classifiers, meth-SemiCancer achieved the highest average F1-score and Matthews correlation coefficient, outperforming other methods. Fine-tuning the model with the unlabeled patient samples by providing the proper pseudo-subtypes, encouraged meth-SemiCancer to generalize better than the supervised neural network-based subtype classification method. meth-SemiCancer is publicly available at https://github.com/cbi-bioinfo/meth-SemiCancer .

Impact of the 12-gene recurrence score in influencing adjuvant chemotherapy prescription in mismatch repair proficient stage II/III colonic carcinoma-a systematic review and meta-analysis

INTRODUCTION

The 12-gene recurrence score (RS) is a clinically validated assay which predicts recurrence risk in patients with stage II/III colon cancer. Decisions regarding adjuvant chemotherapy may be guided using this assay or based on the judgement of tumour board.

AIMS

To assess the concordance between the RS and MDT decisions regarding adjuvant chemotherapy in colon cancer.

METHODS

A systematic review was performed in accordance with PRISMA guidelines. Meta-analyses were performed using the Mantel-Haenszel method using the Review Manager version 5.4 software.

RESULTS

Four studies including 855 patients with a mean age of 68 years (range: 25-90 years) met inclusion criteria. Overall, 79.2% had stage II disease (677/855) and 20.8% had stage III disease (178/855). For the entire cohort, concordant results between the 12-gene assay and MDT were more likely than discordant (odds ratio (OR): 0.38, 95% confidence interval (CI): 0.25-0.56, P < 0.001). Patients were more likely to have chemotherapy omitted than escalated when using the RS (OR: 9.76, 95% CI: 6.72-14.18, P < 0.001). For those with stage II disease, concordant results between the 12-gene assay and MDT were more likely than discordant (OR: 0.30, 95% CI: 0.17-0.53, P < 0.001). In stage II disease, patients were more likely to have chemotherapy omitted than escalated when using the RS (OR: 7.39, 95% CI: 4.85-11.26, P < 0.001).

CONCLUSIONS

The use of the 12-gene signature refutes the decision of tumour board in 25% of cases, with 75% of discordant decisions resulting in omission of adjuvant chemotherapy. Therefore, it is possible that a proportion of such patients are being overtreated when relying on tumour board decisions alone.

Copy Number Variations as Determinants of Colorectal Tumor Progression in Liquid Biopsies

Over the years, increasing evidence has shown that copy number variations (CNVs) play an important role in the pathogenesis and prognosis of Colorectal Cancer (CRC). Colorectal adenomas are highly prevalent lesions, but only 5% of these adenomas ever progress to carcinoma. This review summarizes the different CNVs associated with adenoma-carcinoma CRC progression and with CRC staging. Characterization of CNVs in circulating free-RNA and in blood-derived exosomes augers well with the potential of using such assays for patient management and early detection of metastasis. To overcome the limitations related to tissue biopsies and tumor heterogeneity, using CNVs to characterize tumor-derived materials in biofluids provides less invasive sampling methods and a sample that collectively represents multiple tumor sites in heterogeneous samples. Liquid biopsies provide a source of circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), tumor-derived exosomes (TDE), circulating free RNA, and non-coding RNA. This review provides an overview of the current diagnostic and predictive models from liquid biopsies.

Adjuvant chemotherapy is associated with improved overall survival in select patients with Stage II colon cancer: A National Cancer Database analysis

BACKGROUND AND OBJECTIVES

Guidelines for Stage II colon cancer recommend adjuvant chemotherapy (AC) only for tumors with high-risk features, but long-term outcomes data are mixed. We aimed to determine if AC was associated with a survival benefit in this population.

METHODS

Patients were identified from the National Cancer Database and included if they met the following criteria: diagnosis of Stage II colon cancer, surgery, survival data, and complete data on six high-risk features. The cohort of 57 335 patients was stratified by receipt of AC. Subgroup analysis was performed on patients under the age of 65 years with no comorbidities. Overall survival (OS) was the primary endpoint.

RESULTS

An increasing number of high-risk features was associated with significantly decreased median OS. AC was associated with significantly increased OS for patients with 0, 1, 2, and ≥3 high-risk features. On subgroup analysis, receipt of AC was associated with a reduced risk of death (hazard ratio: 0.66; confidence interval: 0.59-0.74). For patients in the subgroup who had a T4 tumor, AC was associated with increased OS (92.7 vs. 83.6 months).

CONCLUSIONS

AC should be considered for all younger, healthy patients with Stage II colon cancer and may be associated with a survival benefit for patients with T4 disease.

A Novel Combined Tumor Budding-Poorly Differentiated Clusters Grading System Predicts Recurrence and Survival in Stage I-III Colorectal Cancer

Tumor budding (TB) and poorly differentiated clusters (PDCs) are powerful prognostic factors in colorectal cancer (CRC). Despite their morphologic and biological overlap, TB and PDC are assessed separately and are distinguished by an arbitrary cutoff for cell cluster size. This cutoff can be challenging to apply in practice and its biological significance remains unclear. We developed a novel scoring system that incorporates TB and PDC into a single parameter ("Combined Score"; CS), eliminating the need for such cutoffs and allowing the prognostic value of PDC to be captured alongside TB. In a cohort of 481 stage I-III CRC resections, CS was significantly associated with American Joint Committee on Cancer (AJCC) stage, T-stage, N-stage, histologic grade, tumor deposits, lymphovascular invasion, and perineural invasion (P<0.0001). In addition, CS was significantly associated with decreased 5-year recurrence-free survival, overall survival, and disease-specific survival (P<0.0001). TB and PDC showed similar associations with oncologic outcomes, with hazard ratios consistently lower than for CS. The association between CS and oncologic outcomes remained significant in subgroup analyses stratified by AJCC stage, anatomic location (rectum/colon) and neoadjuvant therapy status. On multivariable analysis, CS retained its significant association with oncologic outcomes (P=0.0002, 0.005, and 0.009) for recurrence-free survival, disease-specific survival, and overall survival, respectively. In conclusion, CS provides powerful risk stratification in CRC which is at least equivalent to that of TB and PDC assessed individually. If validated elsewhere, CS has practical advantages and a biological rationale that may make it an attractive alternative to assessing these features separately.

Colorectal cancer subtype identification from differential gene expression levels using minimalist deep learning

Background

Cancer molecular subtyping plays a critical role in individualized patient treatment. In previous studies, high-throughput gene expression signature-based methods have been proposed to identify cancer subtypes. Unfortunately, the existing ones suffer from the curse of dimensionality, data sparsity, and computational deficiency.

Methods

To address those problems, we propose a computational framework for colorectal cancer subtyping without any exploitation in model complexity and generality. A supervised learning framework based on deep learning (DeepCSD) is proposed to identify cancer subtypes. Specifically, based on the differentially expressed genes under cancer consensus molecular subtyping, we design a minimalist feed-forward neural network to capture the distinct molecular features in different cancer subtypes. To mitigate the overfitting phenomenon of deep learning as much as possible, L₁ and L₂ regularization and dropout layers are added.

Results

For demonstrating the effectiveness of DeepCSD, we compared it with other methods including Random Forest (RF), Deep forest (gcForest), support vector machine (SVM), XGBoost, and DeepCC on eight independent colorectal cancer datasets. The results reflect that DeepCSD can achieve superior performance over other algorithms. In addition, gene ontology enrichment and pathology analysis are conducted to reveal novel insights into the cancer subtype identification and characterization mechanisms.

Conclusions

DeepCSD considers all subtype-specific genes as input, which is pathologically necessary for its completeness. At the same time, DeepCSD shows remarkable robustness in handling cross-platform gene expression data, achieving similar performance on both training and test data without significant model overfitting or exploitation of model complexity.

Supplementary Information

The online version contains supplementary material available at (10.1186/s13040-022-00295-w).

The Potential Role of Genomic Signature in Stage II Relapsed Colorectal Cancer (CRC) Patients: A Mono-Institutional Study

Purpose

The absolute benefit of adjuvant chemotherapy in stage II CRC is only 3–4%. The identification of biomarkers through molecular profiling could identify patients who will more benefit from adjuvant chemotherapy.

Patients and Methods

This retrospective analysis examined tissue blocks from 17 patients affected by relapsed stage II CRC, whose comprehensive genomic profiling of tumors was conducted through next-generation sequencing (NGS) via Roche-FoundationOne^®.

Results

Mutations were found in APC (76.5%), TP53 (58.8%) and KRAS (52.9%). Only KRAS wild-type samples showed FBXW7. APC frameshift mutations and MLH1 splice variant were conversely significant correlated (7% v 93%, P = 0.014). The median number of gene mutations reported was 6 (range 2–14). The TP53 mutation was associated most frequently with lung metastasis (P = 0.07) and high tumor budding (P = 0.03). Despite no statistical significance, lung recurrence, LVI/Pni, MSI and more than 6 genetic mutations were correlated to worse DFS and OS. Patients carried co-mutations of TP53-FBXW7 reported the worse DFS (4 v 14 months) and OS (4 v 65 months) compared to the other patients.

Conclusion

According to the present analysis, the setting of relapsed CRC emerges as one of the fields of greatest utility for NGS, looking at personalized cancer care.

A Comparison between Different Management Surgical Approaches in the Treatment of Splenic Flexure Colon Cancer

Background There are many surgical approaches which described extent of resection of the colon for adequate surgical management of splenic flexure cancer, but up till now there is no established surgical procedure, this is because the presence of double lymphatic drainage of the mesenteric vessels. Segmental resection of the colon for the management of splenic flexure cancer was a recently accepted surgical procedure.

Objective In the present study, we aimed to compare three surgical management techniques to clarify the best management approach of Egyptian patients with splenic flexure cancer regarding operative, clinical, and oncological outcomes: segmental resection, and extended left or right hemicolectomy,.

Materials and Methods In the present study, we included 90 patients with splenic flexure cancer. Cases were divided into 3 groups. Each group included 30 patients in order to compare three surgical techniques: segmental resection, extended left hemicolectomy, and extended right hemicolectomy.

Results We have found no statistically significant differences between the three included groups regarding operative findings, postoperative complications, local recurrence, distant recurrence, disease progression, recurrence-free survival rate, progression-free survival rate, and overall survival rate. The operative time was longer, and the number of lymph nodes was higher in the extended right hemicolectomy group (p < 0.001).

Conclusion We have shown that segmental resection of the splenic flexure is surgically and clinically suitable for the adequate management of operable cases of carcinoma of the splenic flexure.

Consensus molecular subtypes of colorectal cancer in clinical practice: A translational approach

The identification of several genetic mutations in colorectal cancer (CRC) has allowed a better comprehension of the prognosis and response to different antineoplastic treatments. Recently, through a systematic process, consensus molecular subtypes (CMS) have been described to characterize genetic and molecular mutations in CRC patients. Through CMS, CRC patients can be categorized into four molecular subtypes of CRC by wide transcriptional genome analysis. CMS1 has microsatellite instability and mutations in CIMP and BRAF pathways. CMS2, distinguished by mutations in specific pathways linked to cellular metabolism, also has a better prognosis. CMS3 has a KRAS mutation as a hallmark. CMS4 presents mutations in fibrogenesis pathways and mesenchymal-epithelial transition, associated with a worse prognosis. CMS classification can be a meaningful step in providing possible answers to important issues in CRC, such as the use of adjuvant chemotherapy in stage II, personalized first-line chemotherapy for metastasic CRC, and possible new target treatments that address specific pathways in each molecular subtype. Understanding CMS is a crucial step in personalized medicine, although prospective clinical trials selecting patients by CMS are required to pass proof-of-concept before becoming a routine clinical tool in oncology routine care.

Prognostic Value of N6-Methyladenosine-Related lncRNAs in Early-Stage Colorectal Cancer: Association With Immune Cell Infiltration and Chemotherapeutic Drug Sensitivity

Purpose: Accumulating evidence indicates that N6-methyladenosine-related long non-coding RNAs (m6A-related lncRNAs) play a crucial role in the occurrence and development of several cancers. We aimed to explore the potential role of m6A-related lncRNA signatures in predicting prognosis for early-stage (stages I and II) colorectal cancer (CRC).

Methods: m6A-related lncRNA data were obtained from The Cancer Genome Atlas. Univariate Cox regression analysis was used to screen for prognostic m6A-related lncRNAs. Immune characteristics were analyzed in different subgroups created via unsupervised clustering analysis. Next, patients were randomly divided into training and test cohorts. In the training cohort, least absolute shrinkage and selection operator (LASSO) regression was performed to establish a prognostic model. The predictive value of the signature was evaluated in the training and test cohorts. Drug sensitivity was also examined.

Results: A total of 1,478 m6A-related lncRNAs were identified. Two subgroups were created based on the expression of seven prognostic m6A-related lncRNAs. Prognosis was worse for cluster 1 than for cluster 2, and cluster 1 was characterized by increased numbers of M2 macrophages, decreased numbers of memory B cells, and higher expression of checkpoint genes when compared with cluster 2. Five m6A-related lncRNAs were selected to establish a risk prediction signature via LASSO regression. The 3 years overall survival (OS) was higher in the low-risk group than in the high-risk group. The area under the curve at 1, 2, and 3 years was 0.929, 0.954, and 0.841 in the training cohort and 0.664, 0.760, and 0.754 in the test cohort, respectively. Multivariate Cox regression analysis suggests that the risk score was an independent predictor of OS in both the training and test cohorts. A prognostic nomogram based on the five m6A-related lncRNAs and their clinical features was built and verified. The high-risk group was more sensitive to chemotherapeutic drugs (camptothecin and cisplatin) than the low-risk group.

Conclusion: We identified two molecular subgroups of early-stage CRC with unique immune features based on seven prognostic m6A-related lncRNAs. Subsequent analyses demonstrated the usefulness of a five m6A-related lncRNA signature as a potential indicator of prognosis in patients with early-stage CRC.

Pathology and Prognosis of Colonic Adenocarcinomas With Intermediate Primary Tumor Stage Between pT2 and pT3

CONTEXT.—

Primary tumor stage (pT) is an important prognostic indicator in colonic adenocarcinomas; however, cases that have no muscle fibers beyond the advancing tumor edge but also show no extension beyond the apparent outer border of muscularis propria (termed pT2int), have not been previously studied.

OBJECTIVE.—

To address the clinicopathologic characteristics and prognosis of pT2int tumors.

DESIGN.—

We recharacterized 168 colon carcinomas and compared pT2int cases to bona fide pT2 and pT3 tumors.

RESULTS.—

In side-by-side analysis, 21 pT2int cases diverged from 29 pT2 tumors only in terms of larger size (P = .03), but they were less likely to show high-grade (P = .03), lymphovascular (P < .001), and extramural venous invasion (P = .04); discontinuous tumor deposits (P = .02); lymph node involvement (P = .001); and advanced stage (P = .001), compared with 118 pT3 tumors. Combining pT2int with pT2 cases (versus pT3) was a better independent predictor of negative lymph nodes in multivariate analysis (P = .04; odds ratio [OR], 3.96; CI, 1.09-14.42) and absent distant metastasis in univariate analysis (P = .04), compared with sorting pT2int with pT3 cases (versus pT2). Proportional hazards regression showed that pT2 and pT2int cases together were associated with better disease-free survival compared with pT3 tumors (P = .04; OR, 3.65; CI, 1.05-12.70). Kaplan-Meier analysis demonstrated that when pT2int were grouped with pT2 tumors, they were significantly less likely to show disease progression compared with pT3 (P = .002; log-rank test) and showed a trend toward better disease-specific survival (P = .06), during a mean patient follow-up of 44.9 months.

CONCLUSIONS.—

These data support the conclusion that pT2int carcinomas have clinicopathologic characteristics and are associated with patient outcomes more closely aligned with pT2 rather than pT3 tumors.

Comprehensive Analysis of a tRNA-Derived Small RNA in Colorectal Cancer

Colorectal cancer often presents as a highly variable disease with myriad forms that are at times difficult to detect in early screenings with sufficient accuracy, for which novel diagnostic methods are an attractive and valuable area of improvement. To improve colorectal cancer diagnosis and prognosis, new biomarkers that can be assembled into a diagnostic panel must be identified, and tRNA-derived small RNAs (tsRNAs) are a particularly interesting and increasingly visible new class of molecules to examine. In this study, small RNA-seq data were profiled for the expression of 104 human tsRNAs in tumor tissue and adjacent normal tissue samples, and a diagnostic model was built based on four differentially expressed tsRNAs: tRF-22-WB86Q3P92, tRF-22-WE8SPOX52, tRF-22-WE8S68L52, tRF-18-8R1546D2. Furthermore, the diagnostic model was validated by two independent validation datasets (AUC was 0.97 and 0.99), and a LASSO model was applied to develop a seven-tsRNA-based risk score model for colorectal cancer prognosis. Finally, a tsRNA-mRNA interaction network was established according to potential mRNA targets predicted by bioinformatic methods. In conclusion, the results suggest that abnormal expression of tsRNA in colorectal cancer may have a functional effect on tumor action and moreover, that some of the tsRNAs identified in this study with diagnostic and prognostic potential could be of clinical significance.

Prognostic impact of tumour sidedness in patients with stage II colon cancer: a single-centre retrospective study

BACKGROUND

The search for high-risk factors in stage II colon cancer (CC) is ongoing and several high-risk factors for stage II CC have been identified; however, the effects of tumour sidedness on prognosis are not clear. This study aims to determine whether tumour sidedness could be identified as another high-risk factor for stage II CC.

METHODS

We retrospectively analysed 189 patients with stage II CC and compared clinicopathological findings and long-term outcomes between the patients with right colonic cancer (RCC) and with left colonic cancer (LCC). Prognostic factors for survival were determined using univariate and Cox proportional regression analyses.

RESULTS

A total of 72 patients were diagnosed with RCC and 117 patients were diagnosed with LCC. Patients with RCC were significantly older (P < 0.001), and the number of harvested lymph nodes was greater in the RCC group (RCC: 25 versus LCC: 19; P = 0.003). The overall survival (OS) was worse in the RCC group than the OS in the LCC group (5-year survival rate - RCC: 81.3% versus LCC: 90.4%; P = 0.025). Cox proportional regression analysis showed that tumour sidedness was an independent prognostic factor for both OS (hazard ratio (HR) 3.78, 95% confidence interval (CI) 1.61-8.85, P = 0.022) and DFS (HR 2.58, 95% CI 1.33-4.99, P = 0.005).

CONCLUSION

Patients with RCC have more negative prognostic factors and worse long-term outcomes than those with LCC in stage II CC. Tumour sidedness is a high-risk factor in stage II CC patients.

Impact of high-risk features for stage II adenocarcinoma of the appendix

BACKGROUND

Clinico-pathological high-risk features are frequently utilized in adjuvant chemotherapy (AC) decisions in stage II colorectal cancer and their utility in stage II appendiceal adenocarcinoma (AA) is not established. The aim of this study is to determine the impact of high-risk features in clinical outcomes and whether high risk features are predictive of AC benefit in stage II AA.

METHODS

Patients with pathological stage II AA between 2010 and 2015 were identified from the National Cancer Database (NCDB) using ICD-O-3 morphology and topography codes: 8140, 8480 and C18.1. High risk stage II AA was defined as having at least one of the following clinicopathological features: T4 tumor, <12 lymph nodes examined, poorly differentiated histology, positive margins, or lymphovascular invasion. Patients with none of these features were defined as low-risk.

RESULTS

A total of 1040 patients with pathological stage II AA were identified. 51.0% males, 84.5% Caucasian; median age 61 (range, 19-90). 46.4% were determined to have high-risk stage II AA. High-risk status was associated with worse OS compared to low-risk in univariate (HR 1.55; 95% CI 1.18-2.02; p = 0.001) and multivariable analyses (HR 1.36; 95% CI 1.03-1.79; p = 0.028). High-risk stage II AA patients had significantly worse 5-year OS compared to low-risk patients (67.1% vs. 74.5%, p = 0.0013). AC was administered in 34.4% (n = 166) of high-risk patients and in 36.5% (n = 203) of low-risk patients. Among high-risk patients, AC was not associated with better OS in univariate (HR 0.86; 95% CI 0.59-1.26; p = 0.448) and multivariable analyses (HR 1.35; 95% CI 0.90-2.04; p = 0.151) compared to no AC. Similarly, among low-risk patients, AC was not associated with better OS in univariate (HR 0.92; 95% CI 0.60-1.39; p = 0.679) and multivariable analyses (HR 1.27; 95% CI 0.81-2.02; p = 0.299) compared to no AC. For high-risk patients, 5-year OS was 68.3% in patients that received AC vs. 66.5% in patients that did not (p = 0.722). For low-risk patients, 5-year OS was 74.0% in patients that received AC vs. 76.3% in patients that did not (p = 0.813).

CONCLUSION

High-risk stage II AA patients had significantly worse 5-year OS compared to low-risk patients. AC did not improve survival regardless of high-risk features in stage II AA in this retrospective study. A prospective randomized clinical trial would be required to determine the impact of high-risk features on AC in stage II AA.

Revised Exon Structure of l-DOPA Decarboxylase (DDC) Reveals Novel Splice Variants Associated with Colorectal Cancer Progression

Colorectal cancer (CRC) is a highly heterogenous malignancy with an increased mortality rate. Aberrant splicing is a typical characteristic of CRC, and several studies support the prognostic value of particular transcripts in this malignancy. l-DOPA decarboxylase (DDC) and its derivative neurotransmitters play a multifaceted role in physiological and pathological states. Our recent data support the existence of 6 DDC novel exons. In this study, we investigated the existence of additional DDC novel exons and transcripts, and their potential value as biomarkers in CRC. Next-generation sequencing (NGS) in 55 human cell lines coupled with Sanger sequencing uncovered 3 additional DDC novel exons and 20 splice variants, 7 of which likely encode new protein isoforms. Eight of these transcripts were detected in CRC. An in-house qPCR assay was developed and performed in TNM II and III CRC samples for the quantification of transcripts bearing novel exons. Extensive biostatistical analysis uncovered the prognostic value of specific DDC novel exons for patients’ disease-free and overall survival. The revised DDC exon structure, the putative protein isoforms with distinct functions, and the prognostic value of novel exons highlight the pivotal role of DDC in CRC progression, indicating its potential utility as a molecular biomarker in CRC.

Current status on microsatellite instability, prognosis and adjuvant therapy in colon cancer: A nationwide survey of medical oncologists, colorectal surgeons and gastrointestinal pathologists

BACKGROUND

There is significant variation in attitude both towards the role of microsatellite instability (MSI) in predicting prognosis, and towards its role in guiding which Stage II colon cancer patients may benefit from adjuvant chemotherapy.

AIM

To examine the current status of specialist attitudes towards MSI in guiding prognosis and adjuvant therapy in stage II colon cancer.

METHODS

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. 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).

RESULTS

164 specialists (45 oncologists, 86 surgeons and 33 pathologists) participated. 80.5% regularly attended colorectal multidisciplinary team (MDT) meetings. 89.63% and 59.26% of specialists reported that MSI status was likely or definitely to influence prognosis in colon cancer and recommendations for adjuvant therapy in Stage II colon cancer respectively. IRT modelling was achieved in 17 pathological features for prognosis. MSI IRT score was 4.47 (95% CI: 4.05-4.68). IRT modelling was achieved in 10 pathological features for adjuvant therapy. MSI IRT score was 3.62 (2.89-4.15). MSI ranked 10 (of 17) in order of importance in determining prognosis and ranked three (of 10) in guiding adjuvant therapy.

CONCLUSION

MSI status is considered an important biomarker when selecting patients for adjuvant therapy in Stage II colon cancer. MSI is also considered useful in prognostication of colon cancer. MSI status was ranked similar to the tumour grade of differentiation and the presence of perineural invasion.

Stem Cell Marker Expression in Early Stage Colorectal Cancer is Associated with Recurrent Intestinal Neoplasia

BACKGROUND

Colorectal cancer (CRC) ranks second in cancer deaths worldwide and presents multiple management challenges, one of which is identifying high risk stage II disease that may benefit from adjuvant therapy. Molecular biomarkers, such as ones that identify stem cell activity, could better stratify high-risk cohorts for additional treatment.

METHODS

To identify possible biomarkers of high-risk disease in early-stage CRC, a discovery set (n = 66) of advanced-stage tumors were immunostained with antibodies to stemness proteins (CD166, CD44, CD26, and LGR5) and then digitally analyzed. Using a second validation cohort (n = 54) of primary CRC tumors, we analyzed protein and gene expression of CD166 across disease stages, and extended our analyses to CD166-associated genes (LGR5, ASCL2, BMI1, POSTN, and VIM) by qRT-PCR.

RESULTS

Stage III and metastatic CRC tumors highly expressed stem cell-associated proteins, CD166, CD44, and LGR5. When evaluated across stages, CD166 protein expression was elevated in advanced-stage compared to early-stage tumors. Notably, a small subset of stage I and II cancers harbored elevated CD166 protein expression, which correlated with development of recurrent cancer or adenomatous polyps. Gene expression analyses of CD166-associated molecules revealed elevated ASCL2 in primary tumors from patients who recurred.

CONCLUSIONS

We identified a protein signature prognostic of aggressive disease in early stage CRC. Stem cell-associated protein and gene expression identified a subset of early-stage tumors associated with cancer recurrence and/or subsequent adenoma formation. Signatures for stemness offer promising fingerprints for stratifying early-stage patients at high risk of recurrence.

Lymphocytic infiltration in stage II microsatellite stable colorectal tumors: A retrospective prognosis biomarker analysis

BACKGROUND

Identifying stage II patients with colorectal cancer (CRC) at higher risk of progression is a clinical priority in order to optimize the advantages of adjuvant chemotherapy while avoiding unnecessary toxicity. Recently, the intensity and the quality of the host immune response in the tumor microenvironment have been reported to have an important role in tumorigenesis and an inverse association with tumor progression. This association is well established in microsatellite instable CRC. In this work, we aim to assess the usefulness of measures of T-cell infiltration as prognostic biomarkers in 640 stage II, CRC tumors, 582 of them confirmed microsatellite stable.

METHODS AND FINDINGS

We measured both the quantity and clonality index of T cells by means of T-cell receptor (TCR) immunosequencing in a discovery dataset (95 patients with colon cancer diagnosed at stage II and microsatellite stable, median age 67, 30% women) and replicated the results in 3 additional series of stage II patients from 2 countries. Series 1 and 2 were recruited in Barcelona, Spain and included 112 fresh frozen (FF, median age 69, 44% women) and 163 formalin-fixed paraffin-embedded (FFPE, median age 67, 39% women) samples, respectively. Series 3 included 270 FFPE samples from patients recruited in Haifa, Northern Israel, as part of a large case-control study of CRC (median age 73, 46% women). Median follow-up time was 81.1 months. Cox regression models were fitted to evaluate the prognostic value of T-cell abundance and Simpson clonality of TCR variants adjusting by sex, age, tumor location, and stage (IIA and IIB). In the discovery dataset, higher TCR abundance was associated with better prognosis (hazard ratio [HR] for ≥Q1 = 0.25, 95% CI 0.10-0.63, P = 0.003). A functional analysis of gene expression on these tumors revealed enrichment in pathways related to immune response. Higher values of clonality index (lower diversity) were not associated with worse disease-free survival, though the HR for ≥Q3 was 2.32 (95% CI 0.90-5.97, P = 0.08). These results were replicated in an independent FF dataset (TCR abundance: HR = 0.30, 95% CI 0.12-0.72, P = 0.007; clonality: HR = 3.32, 95% CI 1.38-7.94, P = 0.007). Also, the association with prognosis was tested in 2 independent FFPE datasets. The same association was observed with TCR abundance (HR = 0.41, 95% CI 0.18-0.93, P = 0.03 and HR = 0.56, 95% CI 0.31-1, P = 0.042, respectively, for each FFPE dataset). However, the clonality index was associated with prognosis only in the FFPE dataset from Israel (HR = 2.45, 95% CI 1.39-4.32, P = 0.002). Finally, a combined analysis combining all microsatellite stable (MSS) samples demonstrated a clear prognosis value both for TCR abundance (HR = 0.39, 95% CI 0.26-0.57, P = 1.3e-06) and the clonality index (HR = 2.13, 95% CI 1.44-3.15, P = 0.0002). These associations were also observed when variables were considered continuous in the models (HR per log2 of TCR abundance = 0.85, 95% CI 0.78-0.93, P = 0.0002; HR per log2 or clonality index = 1.16, 95% CI 1.03-1.31, P = 0.016).

LIMITATIONS

This is a retrospective study, and samples had been preserved with different methods. Validation series lack complete information about microsatellite instability (MSI) status and pathology assessment. The Molecular Epidemiology of Colorectal Cancer (MECC) study had information about overall survival instead of progression-free survival.

CONCLUSION

Results from this study demonstrate that tumor lymphocytes, assessed by TCR repertoire quantification based on a sequencing method, are an independent prognostic factor in microsatellite stable stage II CRC.

Somatic POLE exonuclease domain mutations elicit enhanced intratumoral immune responses in stage II colorectal cancer

Previous studies found patients with POLE exonuclease domain mutations (EDMs) in targeted exons were related to significant better outcomes in stage II-III colorectal cancer (CRC). The detailed mutational profile of the entire POLE exonuclease domain, tumor mutation burden (TMB) and immune cell infiltration in POLE EDMs tumors, and the prognostic value of such mutations in stage II CRCs were largely unknown to us. This study was to clarify the characteristics, immune response and prognostic value of somatic POLE EDMs in stage II CRC. A total of 295 patients with stage II CRC were sequenced by next-generation sequencing with a targeted genetic panel. Simultaneous detection of the immune cells was conducted using a five-color immunohistochemical multiplex technique. The detailed molecular characteristics, tumor-infiltrating lymphocyte (TIL) and prognostic effect of POLE EDMs in stage II CRC were analyzed. For stage II CRCs, the POLE EDMs were detected in 3.1% of patients. Patients with POLE EDMs were more prone to be microsatellite instability-high (MSI-H) (33.3% vs 11.2%, p=0.043), younger at diagnosis (median 46 years vs 62 years, p<0.001) and more common at right-sided location (66.7% vs 23.1%; p=0.003). All patients with POLE EMDs were assessed as extremely high TMB, with a mean TMB of 200.8. Compared with other stage II CRCs, POLE EDMs displayed an enhanced intratumoral cytotoxic T cell response, evidenced by increased numbers of CD8+TILs and CD8A expression. Patients with stage II CRCs could be classified into three risk subsets, with significant different 5 years disease-free survival rates of 100% for POLE EDMs, 82.0% for MSI-H and 63.0% for MSS, p=0.013. In conclusion, characterized by a robust intratumoral T cell response, ultramutated POLE EDMs could be detected in a small subset of stage II CRCs with extremely high TMB. Patients with POLE EDMs had excellent outcomes in stage II CRCs, regardless of MSI status. Sequencing of all the exonuclease domain of POLE gene is recommended in clinical practice.

Assessment of Tumor-infiltrating Lymphocytes Using International TILs Working Group (ITWG) System Is a Strong Predictor of Overall Survival in Colorectal Carcinoma: A Study of 1034 Patients

The presence of increased tumor-infiltrating lymphocytes (TILs) is established as a positive prognostic factor in many malignancies including colorectal carcinoma (CRC). However, multiple different approaches have been used to assess TILs. In 2014, the International TILs Working Group (ITWG) proposed a standardized methodology for evaluating TILs, initially in the context of breast cancer, but subsequently expanded to other malignancies. To date, the efficacy of the ITWG system has not been investigated in a large cohort of all-stage CRC. We, therefore, sought to validate this system in CRC. We used the ITWG system to assess the density of stromal TILs in an unselected cohort of 1034 CRC patients undergoing primary tumor resection at our institution. The percentage TILs' score was categorized into 3 groups: low (0% to 10%), intermediate (15% to 50%), and high (55% to 100%). The mean survival was 53, 67, and 75 months, respectively (P=0.0001). This survival benefit remained statistically significant in multivariate analyses (P=0.0001) and subgroup analyses of mismatch repair-proficient CRCs (P=0.0001), mismatch repair-deficient CRCs (P=0.031), BRAFV600E-mutant CRCs (P=0.0001), and BRAF wild-type CRCs (P=0.001). The predictive value of TILs assessed using the ITWG system was superior to the assessment of intraepithelial lymphocyte performed prospectively using a standard system requiring ≥5 lymphocytes per high-powered field in direct contact with tumor cells or between tumor clusters. We conclude that the ITWG system for assessing TILs is a powerful predictor of all-cause survival in CRC independent of many prognostic factors and superior to the assessment of intraepithelial lymphocytes using a traditional system.

Establishment and validation of a novel nomogram incorporating clinicopathological parameters into the TNM staging system to predict prognosis for stage II colorectal cancer

Background

Survival outcomes are significantly different in stage II colorectal cancer (CRC) patients with diverse clinicopathological features. The objective of this study is to establish a credible prognostic nomogram incorporating easily obtained parameters for stage II CRC patients.

Methods

A total of 1708 stage II CRC patients seen at Fudan University Shanghai Cancer Center (FUSCC) from 2008 to 2013 were retrospectively analyzed in this study. Cases were randomly separated into a training set (n = 1084) and a validation set (n = 624). Univariate and multivariate Cox regression analyses were used to identify independent prognostic factors that were subsequently incorporated into a nomogram. The performance of the nomogram was evaluated by the predicted concordance index (C-index) and ROC curve to calculate the area under the curve (AUC). The clinical utility of the nomogram was evaluated using decision curve analysis (DCA).

Results

In univariate and multivariate analyses, eight parameters were correlated with disease-free survival (DFS), which were subsequently selected to generate a prognostic nomogram based on DFS. For DFS predictions, the C-index values of the nomogram were 0.842 (95% confidence interval (CI) 0.710–0.980), and 0.701 (95% CI 0.610–0.770) for the training and validation sets, respectively. The AUC values of the ROC curves for the nomogram to predicted 1, 3 and 5-year survival were 0.869, 0.858, and 0.777 (training group) and 0.673, 0.714, and 0.706 (validation group), respectively. The recurrence probability calibration curve showed good consistency between actual observations and nomogram-based predictions. DCA showed better clinical application value for the nomogram than the TNM staging system.

Conclusion

A novel nomogram was established and validated in a large population, and the nomogram is a simple-to-use tool for physicians to facilitate postoperative personalized prognostic evaluation and determine therapeutic strategies for stage II CRC patients.

Scoulerine promotes cell viability reduction and apoptosis by activating ROS-dependent endoplasmic reticulum stress in colorectal cancer cells

Scoulerine, an isoquinoline alkaloid isolated from Corydalis plants, has been reported to possess potent anti-proliferative and pro-apoptotic function in cancer cells. However, the effects and underlying mechanisms of scoulerine on colorectal cancer (CRC) progression remain elusive. CCK-8 and LDH assays were used to evaluate cell viability. Apoptosis was assessed by flow cytometry analysis, caspase-3/7 activity assay, and Western blot analysis of Bax, Bcl-2 and cytochrome c (Cyt C) expression. Oxidative stress level was examined by measuring reactive oxygen species (ROS) and glutathione (GSH) contents and superoxide dismutase (SOD) activity. Endoplasmic reticulum (ER) stress activation was detected by Western blot analysis of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) expression. Results showed that scoulerine dose-dependently suppressed CRC cell viability. Scoulerine induced apoptosis and increased caspase-3/7 activity in CRC cells. Bax and cytosolic Cyt C expression was enhanced while Bcl-2 and mitochondrial Cyt C expression was reduced in scoulerine-treated CRC cells. Additionally, scoulerine induced oxidative damage in CRC cells by increasing ROS generation and reducing GSH content and SOD activity. Scoulerine activated ER stress, as evidenced by the increased GRP78 and CHOP expression in CRC cells. Interestingly, blocking ROS production by ROS scavenger N-acetyl-cysteine (NAC) attenuated scoulerine-induced ER stress. Inhibition of ER stress by 4-phenyl butyric acid (4-PBA) abolished scoulerine-induced ROS generation in CRC cells. Blockage of ROS and ER stress attenuated scoulerine-induced cell viability reduction and apoptosis in CRC cells. In conclusion, scoulerine promoted cell viability reduction and apoptosis by activating ROS-dependent ER stress in CRC cells.

Node negative colorectal cancer patients: assesment of high-risk features on recurrence

BACKGROUND

The introduction of population-based screening programs for colorectal cancer (CRC) results in less patients with advanced disease. There is an increase in the amount of node negative CRC, which makes adequate risk stratification for this particular group of patients necessary. The addition of more risk factors to the conventional histological high-risk factors is investigated in this retrospective study.

PATIENTS AND METHODS

A cohort of 227 node negative (stage I and II) CRC patients who were not treated with adjuvant chemotherapy were selected from two previously conducted cohort studies. Detailed histopathological examination was performed by two independent observers and molecular background (BRAF/RAS mutations, microsatellite status (MSI)) was studied. Univariate analyses were used to analyse differences in histological and mutational characteristics between patients with and without recurrence. P-values below 0.05 were considered statistically significant.

RESULTS

Poorly differentiated histology (p:0.002), BRAF mutation (p:0.002) and MSI status (p:0.006) were found significant relevant risk factors that were related to recurrent disease. Poorly differentiated histology was associated with intermediate/high tumor budding (TB) (p:0.001), a BRAF mutation (p:0.001) and MSI status (p:0.001). A combination of all three features (poorly differentiated histology, BRAF and MSI) was more often present in the recurrence group.

CONCLUSIONS

Recurrence in node negative CRC patients could be better predicted when molecular features such as, BRAF mutation and MSI status are incorporated into a model with poorly differentiated CRC. Therefore, these features might help in the selection of patients who possibly will benefit from adjuvant treatment.

The Intestinal Tumour Microenvironment

The tumour microenvironment (TME) of intestinal tumours is highly complex and comprises a network of stromal cells, tumour cells, immune cells and fibroblasts, as well as microorganisms. The tumour location, environmental factors and the tumour cells themselves influence the cells within the TME. Immune cells can destroy tumour cells and are associated with better patient prognosis and response to therapy; however, immune cells are highly plastic and easily influenced to instead promote tumour growth. The interaction between local immune cells and the microbiome can lead to progression or regression of intestinal tumours. In this chapter, we will discuss how tumour development and progression can influence, and be influenced by, the microenvironment surrounding it, focusing on immune and fibroblastic cells, and the intestinal microbiota, particularly in the context of colorectal cancer.

Challenges with colorectal cancer staging: results of an international study

Challenges exist with standardized colorectal cancer reporting despite adoption of the American Joint Committee on Cancer-Staging Manual 8th edition. We performed this study to gauge current practice patterns among a diverse group of surgical pathologists. A web-based questionnaire depicting problematic issues and images related to colorectal carcinoma staging was circulated among 118 surgical pathologists and their responses were correlated with their geographic location (North America vs. Europe vs. others), nature of practice (academic vs. community), the sign-out model (gastrointestinal subspecialty vs. general surgical pathology), and years of professional experience. We found that a substantial number of practicing pathologists ignore recommended-staging criteria in specific settings, particularly with respect to assessment of advanced T stage. Tumors that communicated with the serosa through inflammatory foci were staged as pT3 (49%) or pT4a (51%) by nearly equal numbers of pathologists regardless of level of experience, the sign-out model, or geographic location. Only 65% assigned T stage and margin status based on extent of viable tumor in the neoadjuvant setting. One-third of pathologists, particularly those in Europe (p = 0.015), classified acellular mucin deposits as N1 disease when detected in treatment-naive cases. Nearly 50% of pathologists classified isolated tumor cells (i.e., deposits <0.2 mm) in lymph nodes as metastatic disease (i.e., pN1, p = 0.02). Our results suggest that pathologists ignore recommendations that are based on insufficient data and apply individualized criteria when faced with situations that are not addressed in the American Joint Committee on Cancer Staging Manual 8th edition. These variations in practice limit the ability to compare outcome data across different institutions and draw attention to areas that require further study.

A network view of microRNA and gene interactions in different pathological stages of colon cancer

BACKGROUND

Colon cancer is one of the common cancers in human. Although the number of annual cases has decreased drastically, prognostic screening and translational methods can be improved. Hence, it is critical to understand the molecular mechanisms of disease progression and prognosis.

RESULTS

In this study, we develop a new strategy for integrating microRNA and gene expression profiles together with clinical information toward understanding the regulation of colon cancer. Particularly, we use this approach to identify microRNA and gene expression networks that are specific to certain pathological stages. To demonstrate the application of our method, we apply this approach to identify microRNA and gene interactions that are specific to pathological stages of colon cancer in The Cancer Genome Atlas (TCGA) datasets.

CONCLUSIONS

Our results show that there are significant differences in network connections between miRNAs and genes in different pathological stages of colon cancer. These findings point to a hypothesis that these networks signify different roles of microRNA and gene regulation in the pathogenesis and tumorigenesis of colon cancer.

The Use of Circulating Tumor DNA to Monitor and Predict Response to Treatment in Colorectal Cancer

Background: Colorectal cancer is one of the most common cancers worldwide and has a high mortality rate following disease recurrence. Treatment efficacy is maximized by providing tailored cancer treatment, ideally involving surgical resection and personalized neoadjuvant and adjuvant therapies, including chemotherapy, radiotherapy and increasingly, targeted therapy. Early detection of recurrence or disease progression results in more treatable disease and is essential to improving survival outcomes. Recent advances in the understanding of tumor genetics have resulted in the discovery of circulating tumor DNA (ctDNA). A growing body of evidence supports the use of these sensitive biomarkers in detecting residual disease and diagnosing recurrence as well as enabling targeted and tumor-specific adjuvant therapies. Methods: A literature search in Pubmed was performed to identify all original articles preceding April 2019 that utilize ctDNA for the purpose of monitoring response to colorectal cancer treatment. Results: Ninety-two clinical studies were included. These studies demonstrate that ctDNA is a reliable measure of tumor burden. Studies show the utility of ctDNA in assessing the adequacy of surgical tumor clearance and changes in ctDNA levels reflect response to systemic treatments. ctDNA can be used in the selection of targeted treatments. The reappearance or increase in ctDNA, as well as the emergence of new mutations, correlates with disease recurrence, progression, and resistance to therapy, with ctDNA measurement allowing more sensitive monitoring than currently used clinical tools. Conclusions: ctDNA shows enormous promise as a sensitive biomarker for monitoring response to many treatment modalities and for targeting therapy. Thus, it is emerging as a new way for guiding treatment decisions-initiating, altering, and ceasing treatments, or prompting investigation into the potential for residual disease. However, many potentially useful ctDNA markers are available and more work is needed to determine which are best suited for specific purposes and for improving specific outcomes.

RBP7 is a clinically prognostic biomarker and linked to tumor invasion and EMT in colon cancer

RBP7 is a member of the cellular retinol-binding protein (CRBP) family and previous data suggested a link between CRBPs and the malignant transformation of colon cancer cells. Here, we investigated the potential of RBP7 as a predictive biomarker for patients with colon cancer and determined its functional relevance for tumor progression. We analyzed RBP7 protein and mRNA expression in independent tissue collections of colon cancers with recorded follow-up data, including data from TCGA. We used gene set enrichment analyses to characterize its functional role. Effects of RBP7 on migration and invasion were determined in transwell assays. High expression of RBP7 was an independent biomarker of poor cancer specific survival in early and late stage colon cancer, and linked to colon cancer progression. Gene set enrichment analysis revealed a strong association of RBP7, colon cancer invasion and epithelial mesenchymal transition (EMT). Ectopic expression of RBP7 increased migration and invasion of colon cancer cells. Our findings demonstrate that RBP7 is a strong prognostic biomarker in colon cancer that functionally contributes to the malignant phenotype of colon cancer cells. This may aid in risk stratification for the therapeutic management of patients with colorectal cancer.

DeepCC: a novel deep learning-based framework for cancer molecular subtype classification

Molecular subtyping of cancer is a critical step towards more individualized therapy and provides important biological insights into cancer heterogeneity. Although gene expression signature-based classification has been widely demonstrated to be an effective approach in the last decade, the widespread implementation has long been limited by platform differences, batch effects, and the difficulty to classify individual patient samples. Here, we describe a novel supervised cancer classification framework, deep cancer subtype classification (DeepCC), based on deep learning of functional spectra quantifying activities of biological pathways. In two case studies about colorectal and breast cancer classification, DeepCC classifiers and DeepCC single sample predictors both achieved overall higher sensitivity, specificity, and accuracy compared with other widely used classification methods such as random forests (RF), support vector machine (SVM), gradient boosting machine (GBM), and multinomial logistic regression algorithms. Simulation analysis based on random subsampling of genes demonstrated the robustness of DeepCC to missing data. Moreover, deep features learned by DeepCC captured biological characteristics associated with distinct molecular subtypes, enabling more compact within-subtype distribution and between-subtype separation of patient samples, and therefore greatly reduce the number of unclassifiable samples previously. In summary, DeepCC provides a novel cancer classification framework that is platform independent, robust to missing data, and can be used for single sample prediction facilitating clinical implementation of cancer molecular subtyping.

Treatment of splenic flexure colon cancer: a comparison of three different surgical procedures: Experience of a high volume cancer center

Extended right or left hemicolectomy are the most common surgical treatments for splenic flexure colon cancer. Extended resection (including distal pancreasectomy and/or splenectomy), has been often indicated for the treatment for the splenic flexure cancer, because the lymphatic drainage at this site is poorly defined and assumed as heterogeneous. Between January 2006 and May 2016, 103 patients with splenic flexure colon cancer were enrolled in the study. We evaluated the clinicopathological findings and outcomes of all patients and associated them to the different surgical treatment. Out of 103 selected cases an extended right hemicolectomy was performed in 22 (21.4%) patients, an extended left hemicolectomy in 24 (23.3%) patients, a segmental resection of the splenic flexure in 57 (55.3%) patients; the combined resection of adjacent organs showing tumor adherence was carried out in 11 (10.7%) patients. The tumor infiltrated near organs (T4) in 5 patients. No significant differences in complications were found among the three groups. In all groups no differences were found in the total number of harvested lymphnodes. After a median follow-up of 42 months, 30 recurrences and 19 deaths occurred (12 for tumor progression). There was no difference in overall and progression free survival among the three different surgical treatments. According to our results, the partial resection of splenic flexure was not associated with a worse prognosis and it was leading for a satisfactory oncological outcome. It is our opinion that the extended surgery is seldomly indicated to cure splenic flexure cancer.

Adjuvant chemotherapy in stage II-III operated colon cancer patients from a nontrial cohort in a low colon cancer prevalence country with predominant use of modified CAPOX

BACKGROUND

Data regarding the practice of adjuvant chemotherapy, specifically with modified CAPOX, and survival outcomes in operated colon cancer patients from a nontrial cohort in a lower-middle income and low prevalence nation like India is scarce.

MATERIALS AND METHODS

Patients who underwent upfront curative resection for colon cancer from January 2013 to December 2016 were analyzed for baseline variables and outcomes.

RESULTS

A total of 491 patients underwent curative resection in the predefined time period. The median age of the patients was 53 years (range: 17-87). Patients with Stage I, Stage II, and Stage III disease comprised 7.9%, 44.8%, and 45.4% of the entire cohort, respectively. Patients with Stage I cancer were observed. Adjuvant chemotherapy was planned for 384 patients (78.2%), with the doublet regimens (capecitabine-oxaliplatin, or 5-fluorouracil-oxaliplatin) being used commonly (77.6%). Common toxicities were Hand-foot syndrome (Grade 2/3 - 21.4%) and peripheral neuropathy (Grade 2/3 - 20.1%). About 85% of patients receiving monotherapy (capecitabine or 5 fluorouracil) and 81.2% of patients receiving doublet chemotherapy (mCAPOX or modified FOLFOX-7) completed their planned adjuvant treatment. With a median follow-up of 22 months, estimated 3 years event-free survival was 86%, and overall survival (OS) was 93.6%. Stage, younger age (<50 years), underlying cardiovascular abnormalities, need for dose reductions and noncompletion of planned chemotherapy predicted for inferior estimated 3-year OS on multivariate analysis.

CONCLUSIONS

Adjuvant chemotherapy especially with modified CAPOX appears well tolerated in the Indian population and early survival outcomes appear to be comparable to published literature.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

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

Objective.—

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

Data Sources.—

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

Conclusions.—

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

Gene pair based prognostic signature for colorectal colon cancer

BACKGROUND

The identification of high-risk colorectal cancer (CRC) patient is key to individualized treatment after surgery and reliable prognostic biomarkers are needed identifying high-risk CRC patients.

METHODS

We developed a gene pair based prognostic signature that could can the prognosis risk in patients with CRC. This study retrospectively analyzed 4 public CRC datasets, and 1123 patients with CRC were divided into a training cohort (n = 300) and 3 independent validation cohorts (n = 507, 226, and 90 patients).

RESULTS

A signature of 9 prognosis-related gene pairs (PRGPs) consisting of 17 unique genes was constructed. Then, a PRGP index (PRGPI) was constructed and divided patients into high- and low-risk groups according to the signature score. Patients in the high-risk group showed a poorer relapse-free survival than the low-risk group in both the training cohort [hazard ratio (HR) range, 4.6, 95% confidence interval (95% CI), 2.55-8.32; P < .0001] and meta-validation set (hazard ratio range, 4.09, 95% CI, 1.99-8.39; P < .0001). The PRGPI signature achieved a higher accuracy [mean concordance index (C-index): 0.6∼0.74] than a commercialized molecular signature (mean C-index, 0.48∼0.56) for estimation of relapse-free survival in comparable validation sets.

CONCLUSION

The gene pair based prognostic signature is a promising biomarker for estimating relapse-free survival of CRC.

Establishment of a 12-gene expression signature to predict colon cancer prognosis

A robust and accurate gene expression signature is essential to assist oncologists to determine which subset of patients at similar Tumor-Lymph Node-Metastasis (TNM) stage has high recurrence risk and could benefit from adjuvant therapies. Here we applied a two-step supervised machine-learning method and established a 12-gene expression signature to precisely predict colon adenocarcinoma (COAD) prognosis by using COAD RNA-seq transcriptome data from The Cancer Genome Atlas (TCGA). The predictive performance of the 12-gene signature was validated with two independent gene expression microarray datasets: GSE39582 includes 566 COAD cases for the development of six molecular subtypes with distinct clinical, molecular and survival characteristics; GSE17538 is a dataset containing 232 colon cancer patients for the generation of a metastasis gene expression profile to predict recurrence and death in COAD patients. The signature could effectively separate the poor prognosis patients from good prognosis group (disease specific survival (DSS): Kaplan Meier (KM) Log Rank p = 0.0034; overall survival (OS): KM Log Rank p = 0.0336) in GSE17538. For patients with proficient mismatch repair system (pMMR) in GSE39582, the signature could also effectively distinguish high risk group from low risk group (OS: KM Log Rank p = 0.005; Relapse free survival (RFS): KM Log Rank p = 0.022). Interestingly, advanced stage patients were significantly enriched in high 12-gene score group (Fisher’s exact test p = 0.0003). After stage stratification, the signature could still distinguish poor prognosis patients in GSE17538 from good prognosis within stage II (Log Rank p = 0.01) and stage II & III (Log Rank p = 0.017) in the outcome of DFS. Within stage III or II/III pMMR patients treated with Adjuvant Chemotherapies (ACT) and patients with higher 12-gene score showed poorer prognosis (III, OS: KM Log Rank p = 0.046; III & II, OS: KM Log Rank p = 0.041). Among stage II/III pMMR patients with lower 12-gene scores in GSE39582, the subgroup receiving ACT showed significantly longer OS time compared with those who received no ACT (Log Rank p = 0.021), while there is no obvious difference between counterparts among patients with higher 12-gene scores (Log Rank p = 0.12). Besides COAD, our 12-gene signature is multifunctional in several other cancer types including kidney cancer, lung cancer, uveal and skin melanoma, brain cancer, and pancreatic cancer. Functional classification showed that seven of the twelve genes are involved in immune system function and regulation, so our 12-gene signature could potentially be used to guide decisions about adjuvant therapy for patients with stage II/III and pMMR COAD.

Neoadjuvant Chemotherapy is Associated with Lower Lymph Node Counts in Colon Cancer

Adequate lymphadenectomy is associated with improved survival in patients who undergo oncologic resection of colorectal cancer and has been identified as a quality metric. Neoadjuvant chemotherapy has been found to be associated with collection of <12 lymph nodes in patients with rectal cancer. The purpose of this study was to evaluate patient and operative risk factors for inadequate lymph node retrieval during oncologic colectomy. The 2014 American College of Surgeons National Surgical Quality Improvement Program Participant Use File data set for oncologic colectomy (n = 9077) was analyzed. Patient- and operation-related factors were assessed by univariate and multivariate regression analyses to determine factors associated with the number of lymph nodes collected. Adequate lymphadenectomy was defined by collection of >12 lymph nodes. Of 9077 patients with a diagnosis of colon cancer who underwent colectomy, a minimum of 12 lymph nodes was harvested in 7897 (87%). Significant factors independently associated with inadequate lymphadenectomy included preoperative chemotherapy, emergent surgery, and T1 tumors (all P < 0.05). A large majority of patients who undergo colectomy for colon cancer have at least 12 lymph nodes collected. Preoperative chemotherapy is a major risk factor for inadequate lymph node retrieval. Recognition of factors associated with inadequate lymphadenectomy may improve colectomy lymph node yield and survival in patients with colon cancer.

Nomogram Integrating Genomics with Clinicopathologic Features Improves Prognosis Prediction for Colorectal Cancer

The current tumor staging system is insufficient for predicting the outcomes for patients with colorectal cancer because of its phenotypic and genomic heterogeneity. Integrating gene expression signatures with clinicopathologic factors may yield a predictive accuracy exceeding that of the currently available system. Twenty-seven signatures that used gene expression data to predict colorectal cancer prognosis were identified and re-analyzed using bioinformatic methods. Next, clinically annotated colorectal cancer samples (n = 1710) with the corresponding expression profiles, that predicted a patient's probability of cancer recurrence, were pooled to evaluate their prognostic values and establish a clinicopathologic-genomic nomogram. Only 2 of the 27 signatures evaluated showed a significant association with prognosis and provided a reasonable prediction accuracy in the pooled cohort (HR, 2.46; 95% CI, 1.183-5.132, P < 0.001; AUC, 60.83; HR, 2.33; 95% CI, 1.218-4.453, P < 0.001; AUC, 71.34). By integrating the above signatures with prognostic clinicopathologic features, a clinicopathologic-genomic nomogram was cautiously constructed. The nomogram successfully stratified colorectal cancer patients into three risk groups with remarkably different DFS rates and further stratified stage II and III patients into distinct risk subgroups. Importantly, among patients receiving chemotherapy, the nomogram determined that those in the intermediate- (HR, 0.98; 95% CI, 0.255-0.679, P < 0.001) and high-risk (HR, 0.67; 95% CI, 0.469-0.957, P = 0.028) groups had favorable responses.Implications: These findings offer evidence that genomic data provide independent and complementary prognostic information, and incorporation of this information refines the prognosis of colorectal cancer. Mol Cancer Res; 16(9); 1373-84. ©2018 AACR.

Clinical Signatures of Mucinous and Poorly Differentiated Subtypes of Colorectal Adenocarcinomas by a Propensity Score Analysis of an Independent Patient Database from Three Phase III Trials

BACKGROUND

Although colorectal cancer comprises several histological subtypes, the influences of histological subtypes on disease progression and treatment responses remain controversial.

OBJECTIVE

We sought to evaluate the prognostic relevance of mucinous and poorly differentiated histological subtypes of colorectal cancer by the propensity score weighting analysis of prospectively collected data from multi-institute phase III trials.

DESIGN

Independent patient data analysis of a pooled database from 3 phase III trials was performed.

SETTINGS

An integrated database of 3 multicenter prospective clinical trials (the Japanese Foundation for Multidisciplinary Treatment of Cancer 7, 15, and 33) was the source of study data.

INTERVENTIONS

Surgery alone or postoperative adjuvant chemotherapy was offered in patients with resectable colorectal cancer.

MAIN OUTCOME MEASURES

To balance essential variables more strictly for the comparison analyses, propensity score weighting was conducted with the use of a multinomial logistic regression model. We evaluated the clinical signatures of mucinous and poorly differentiated subtypes with regard to postoperative survival, recurrence, and chemosensitivity.

RESULTS

Of 5489 patients, 136 (2.5%) and 155 (2.8%) were pathologically diagnosed with poorly differentiated and mucinous subtypes. The poorly differentiated subtypes were associated with a poorer prognosis than the "others" group (HR, 1.69; 95% CI, 1.00-2.87; p = 0.051), particularly in the patient subgroup of adjuvant chemotherapy (HR, 2.16). Although the mucinous subtype had a marginal prognostic impact among patients with stage I to III colorectal cancer (HR, 1.33; 95% CI, 0.90-1.96), it was found to be an independent prognostic factor in the subpopulation of patients with stage II disease, being associated with a higher prevalence of peritoneal recurrence.

LIMITATIONS

The treatment regimens of postoperative chemotherapy are now somewhat outdated.

CONCLUSIONS

Both mucinous and poorly differentiated subtypes have distinct clinical characteristics. Patients with the mucinous subtype require special attention during follow-up, even for stage II disease, because of the risk of peritoneal or local recurrence. See Video Abstract at http://links.lww.com/DCR/A531.

Evolving notions on immune response in colorectal cancer and their implications for biomarker development

INTRODUCTION

Colorectal cancer (CRC) still represents the third most commonly diagnosed type of cancer in men and women worldwide. CRC is acknowledged as a heterogeneous disease that develops through a multi-step sequence of events driven by clonal selections; this observation is sustained by the fact that histologically similar tumors may have completely different outcomes, including a varied response to therapy.

METHODS

In "early" and "intermediate" stage of CRC (stages II and III, respectively) there is a compelling need for new biomarkers fit to assess the metastatic potential of their disease, selecting patients with aggressive disease that might benefit from adjuvant and targeted therapies. Therefore, we review the actual notions on immune response in colorectal cancer and their implications for biomarker development.

RESULTS

The recognition of the key role of immune cells in human cancer progression has recently drawn attention on the tumor immune microenvironment, as a source of new indicators of tumor outcome and response to therapy. Thus, beside consolidated histopathological biomarkers, immune endpoints are now emerging as potential biomarkers.

CONCLUSIONS

The introduction of immune signatures and cellular and molecular components of the immune system as biomarkers is particularly important considering the increasing use of immune-based cancer therapies as therapeutic strategies for cancer patients.

Prognostic value of loss of heterozygosity and sub-cellular localization of SMAD4 varies with tumor stage in colorectal cancer

Background

Although loss of heterozygosity (LOH) at chromosome location 18q21 and decreased expression of SMAD4 in invasive colorectal cancers (CRCs) correlate with poor patient survival, the prognostic value of LOH at 18q21 and sub-cellular localization of SMAD4 have not been evaluated in relation to tumor stage.

Methods

Genomic DNA samples from 209 formalin-fixed, paraffin-embedded sporadic CRC tissues and their matching controls were analyzed for 18q21 LOH, and corresponding tissue sections were evaluated by immunohistochemistry for expression of SMAD4 and assessed for its sub-cellular localization (nuclear vs. cytoplasmic). In addition, 53 frozen CRCs and their matching control tissues were analyzed for their mutational status and mRNA expression of SMAD4. The phenotypic expression pattern and LOH status were evaluated for correlation with patient survival by the use of Kaplan-Meier and Cox regression models.

Results

LOH of 18q21 was detected in 61% of the informative cases. In 8% of the cases, missense point mutations were detected in Smad4. In CRCs, relative to controls, there was increased SMAD4 staining in the cytoplasm (74%) and decreased staining in the nuclei (37%). LOH of 18q21 and high cytoplasmic localization of SMAD4 were associated with shortened overall survival of Stage II patients, whereas low nuclear expression of SMAD4 was associated with worse survival, but only for patients with Stage III CRCs.

Conclusions

LOH of 18q21 and high cytoplasmic localization of SMAD4 in Stage II CRCs and low nuclear SMAD4 in Stage III CRCs are predictors of shortened patient survival.

Ezrin expression combined with MSI status in prognostication of stage II colorectal cancer

Currently used factors predicting disease recurrence in stage II colorectal cancer patients are not optimal for risk stratification. Thus, new biomarkers are needed. In this study the applicability of ezrin protein expression together with MSI status and BRAF mutation status were tested in predicting disease outcome in stage II colorectal cancer. The study population consisted of 173 stage II colorectal cancer patients. Paraffin-embedded cancer tissue material from surgical specimens was used to construct tissue microarrays (TMAs) with next-generation technique. The TMA-slides were subjected to following immunohistochemical stainings: MLH1, MSH2, MSH6, PMS2, ezrin and anti-BRAF V600E antibody. The staining results were correlated with clinicopathological variables and survival. In categorical analysis, high ezrin protein expression correlated with poor disease-specific survival (p = 0.038). In univariate analysis patients having microsatellite instabile / low ezrin expression tumors had a significantly longer disease-specific survival than patients having microsatellite stable / high ezrin expression tumors (p = 0.007). In multivariate survival analysis, the presence of BRAF mutation was associated to poor overall survival (p = 0.028, HR 3.29, 95% CI1.14–9.54). High ezrin protein expression in patients with microsatellite stable tumors was linked to poor disease-specific survival (p = 0.01, HR 5.68, 95% CI 1.53–21.12). Ezrin protein expression is a promising biomarker in estimating the outcome of stage II colorectal cancer patients. When combined with microsatellite status its ability in predicting disease outcome is further improved.