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

The Glasgow Microenvironment Score: an exemplar of contemporary biomarker evolution in colorectal cancer

Colorectal cancer remains a leading cause of mortality worldwide. Significant variation in response to treatment and survival is evident among patients with similar stage disease. Molecular profiling has highlighted the heterogeneity of colorectal cancer but has had limited impact in daily clinical practice. Biomarkers with robust prognostic and therapeutic relevance are urgently required. Ideally, biomarkers would be derived from H&E sections used for routine pathological staging, have reliable sensitivity and specificity, and require minimal additional training. The biomarker targets would capture key pathological features with proven additive prognostic and clinical utility, such as the local inflammatory response and tumour microenvironment. The Glasgow Microenvironment Score (GMS), first described in 2014, combines assessment of peritumoural inflammation at the invasive margin with quantification of tumour stromal content. Using H&E sections, the Klintrup-Mäkinen (KM) grade is determined by qualitative morphological assessment of the peritumoural lymphocytic infiltrate at the invasive margin and tumour stroma percentage (TSP) calculated in a semi-quantitative manner as a percentage of stroma within the visible field. The resulting three prognostic categories have direct clinical relevance: GMS 0 denotes a tumour with a dense inflammatory infiltrate/high KM grade at the invasive margin and improved survival; GMS 1 represents weak inflammatory response and low TSP associated with intermediate survival; and GMS 2 tumours are typified by a weak inflammatory response, high TSP, and inferior survival. The prognostic capacity of the GMS has been widely validated while its potential to guide chemotherapy has been demonstrated in a large phase 3 trial cohort. Here, we detail its journey from conception through validation to clinical translation and outline the future for this promising and practical biomarker.

The Association of Mismatch Repair Status with Microscopically Positive (R1) Margins in Stage III Colorectal Cancer: A Retrospective Cohort Study

BACKGROUND

There is mounting evidence that microscopically positive (R1) margins in patients with colorectal cancer (CRC) may represent a surrogate for aggressive cancer biology rather than technical failure during surgery. However, whether detectable biological differences exist between CRC with R0 and R1 margins is unknown. We sought to investigate whether mismatch repair (MMR) status differs between Stage III CRC with R0 or R1 margins.

METHODS

Patients treated for Stage III CRC from January 1, 2016 to December 31, 2019 were identified by using the Danish Colorectal Cancer Group database. Patients were stratified according to MMR status (proficient [pMMR] vs. deficient [dMMR]) and margin status. Outcomes of interest included the R1 rate according to MMR and overall survival.

RESULTS

A total of 3636 patients were included, of whom 473 (13.0%) had dMMR colorectal cancers. Patients with dMMR cancers were more likely to be elderly, female, and have right-sided cancers. R1 margins were significantly more common in patients with dMMR cancers (20.5% vs. 15.2%, p < 0.001), with the greatest difference seen in the rate of R1 margins related to the primary tumour (8.9% vs. 4.7%) rather than to lymph node metastases (11.6% vs. 10.5%). This association was seen in both right- and left-sided cancers. On multivariable analyses, R1 margins, but not MMR status, were associated with poorer survival, alongside age, pN stage, perineural invasion, and extramural venous invasion.

CONCLUSIONS

In patients with Stage III CRC, dMMR status is associated with increased risks of R1 margins following potentially curative surgery, supporting the use of neoadjuvant immunotherapy in this patient group.

Assessing venous invasion in stage II colon cancer: optimal elastin stains and survival analysis

AIMS

Venous invasion (VI) in colorectal carcinoma influences treatment strategies, especially in early stages. Despite elastin staining effectiveness in detecting VI, guidelines for its routine application, including the optimal number of slides for staining, are limited.

METHODS

Elastin staining was performed for VI assessment in patients with colorectal adenocarcinoma. Patients were categorised into two groups: single elastin stain group (SEG, n=248) and multiple elastin stain group (MEG, n=204).

RESULTS

The average number of elastin-stained blocks was 2±1.7, increasing to 3.3±1.9 in MEG. VI detection was significantly higher in patients in MEG (50.5%) compared with SEG (37.0%) (p=0.004). VI detection rate was higher in MEG (63.7%) than in SEG (46.0%) among patients with stage III-IV disease (p=0.011), but did not significantly differ among patients with stage I-II disease. Staining two blocks improved VI detection without additional gains from more stains. Compared with elastin performed on a single block, VI detected by elastin stain on two or more blocks did not significantly impact progression-free or disease-free survival with stage II patients.

CONCLUSIONS

Employing two elastin stains on separate blocks significantly enhances VI detection in colorectal carcinoma without additional benefits from more extensive staining. This study suggests that while increasing sensitivity for VI detection, staining beyond two blocks may not benefit prognostication and could be counterproductive, warranting further research. We emphasise the need for strategic use of the elastin stain and cautious interpretation of the increased detection sensitivity of multiple elastin stains.

Circumferential resection margin positivity due to direct or indirect tumour involvement in rectal cancer - a call for better stratification

BACKGROUND

A positive circumferential resection margin (CRM) after rectal cancer surgery, which can be the result of direct or indirect tumour involvement, has consistently been associated with increased local recurrence and poorer survival. However, little is known of the differential impact of the mode of tumour involvement on outcomes.

METHODS

1460 consecutive patients undergoing rectal cancer resection between 2003 and 2018 were retrospectively assessed. Histopathology reports for patients with a positive CRM were reviewed to determine cases of direct (R1-tumour) or indirect tumour involvement (R1-other). Disease-free survival (DFS) and overall survival (OS) were assessed by Kaplan-Meier analysis. The role of the mode of CRM positivity was examined by univariate and multivariate Cox proportional hazards models.

RESULTS

Eighty-five patients had an R1 resection due to CRM involvement (5.8%). Of those, 69 were due to direct tumour involvement, while 16 were from indirect causes. Kaplan-Meier analysis revealed that R1-other was associated with increased OS (hazard ratio 0.40, log-rank P = 0.006) and DFS (P = 0.043). Multivariate regression confirmed that the mode of CRM positivity was an independent predictor of OS. More interestingly, the patterns of recurrence were different between the two groups, with R1-tumour leading to significantly more local recurrence (P = 0.04).

CONCLUSIONS

Our data strongly suggests that direct tumour involvement of the CRM confers worse prognosis after rectal cancer surgery. Importantly, differences in the site and frequency of recurrences make a case for better stratification of patients with a positive CRM to guide treatment decisions.

The Relationship between Tumor Budding and Tumor Deposits in Patients with Stage III Colorectal Carcinoma

Background/Objectives: Recently, some new morphological features of colorectal cancer have been discovered as important prognostic factors; in this paper, we study the relationship between tumor budding (TB) and tumor deposits (TDs). Methods: The retrospective cohort study included 90 patients with pathohistologically confirmed stage III CRC who were treated with radical surgical resection. All hematoxylin and eosin (H and E)-stained slides from each patient were reviewed, and histological parameters were recorded. The samples were divided into two groups with similar sizes: a group without TDs (N = 51) and a control group with TDs (N = 39). The presence and TB grade were further analyzed in these groups and compared with other clinical and histological features. Results: The prevalence of TB in the investigated cohort was unexpectedly high (94.4%). Overall, there were 23 (25.6%) Bd1, 20 (22.2%) Bd2, and 47 (52.2%) Bd3 cases. The presence of TDs was significantly associated with a higher number of TB (p < 0.001, OR 16.3) and, consequently, with a higher TB grade (p = 0.004, OR 11.04). A higher TB grade (p = 0.001, HR 2.28; 95% CI 1.93-4.76) and a growing number of TDs (p = 0.014, HR 1.52; 95% CI 1.09-2.1) were statistically significantly associated with shorter survival. Conclusions: TDs appear more often in patients with higher TB grades in stage III CRC. A higher TB grade and a growing number of TDs were statistically significantly associated with shorter overall survival. These results could give additional emphasis to the importance of TB as an adverse prognostic factor since a strong relationship with TDs has been demonstrated.

Sporadic Polyps of the Colorectum

Colorectal polyps are common, and their diagnosis and classification represent a major component of gastrointestinal pathology practice. The majority of colorectal polyps represent precursors of either the chromosomal instability or serrated neoplasia pathways to colorectal carcinoma. Accurate reporting of these polyps has major implications for surveillance and thus for cancer prevention. In this review, we discuss the key histologic features of the major colorectal polyps with a particular emphasis on diagnostic pitfalls and areas of contention.

Extracting structured information from unstructured histopathology reports using generative pre-trained transformer 4 (GPT-4)

Deep learning applied to whole-slide histopathology images (WSIs) has the potential to enhance precision oncology and alleviate the workload of experts. However, developing these models necessitates large amounts of data with ground truth labels, which can be both time-consuming and expensive to obtain. Pathology reports are typically unstructured or poorly structured texts, and efforts to implement structured reporting templates have been unsuccessful, as these efforts lead to perceived extra workload. In this study, we hypothesised that large language models (LLMs), such as the generative pre-trained transformer 4 (GPT-4), can extract structured data from unstructured plain language reports using a zero-shot approach without requiring any re-training. We tested this hypothesis by utilising GPT-4 to extract information from histopathological reports, focusing on two extensive sets of pathology reports for colorectal cancer and glioblastoma. We found a high concordance between LLM-generated structured data and human-generated structured data. Consequently, LLMs could potentially be employed routinely to extract ground truth data for machine learning from unstructured pathology reports in the future. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

The use of core descriptors from the ENiGMA code study in recent literature: a systematic review

AIM

The heterogeneity in data quality presented in studies regarding Crohn's anal fistula (CAF) limit extrapolation into clinical practice. The ENiGMA collaborators established a core descriptor set to standardize reporting of CAF. The aim of this work was to quantify the use of these descriptors in recent literature.

METHOD

We completed a systematic review of PubMed and the Cochrane Library, extracting publications from the past 10 years specific to the clinical interventions and outcomes of CAF, and reported in line with PRISMA guidance. Each article was assessed for inclusion of ENiGMA descriptors. The median number of descriptors per publication was evaluated along with the overall frequency of each individual descriptor. Use of ENiGMA descriptors was compared between medical and procedural publications.

RESULTS

Ninety publications were included. The median number of descriptors was 15 of 37; 16 descriptors were used in over half of the publications while 17 were used in fewer than a third. Descriptors were more frequently used in procedural (n = 16) than medical publications (n = 14) (p = 0.031). In procedural publications, eight descriptors were more frequently used including Faecal incontinence, Number of previous fistula interventions, Presence and severity of anorectal stenosis and Current proctitis. Medical publications were more likely to include Previous response to biological therapy and Duration and type of current course of biological therapy.

CONCLUSION

With many descriptors being used infrequently and variations between medical and procedural literature, the colorectal community should assess the need for all 37 descriptors.

Current Challenges and Controversies in Colorectal Carcinoma Pathologic Staging-A Practical Guide

The pathologic assessment of colorectal carcinoma specimens plays a crucial role in the therapeutic management of patients and disease prognostication. The TNM staging system is used globally and is a critical component of colorectal carcinoma pathology reporting. However, our experience informs us that there are significant variations in the assignment of the TNM stage, both between pathologists and between hospital centers. We identify several potential reasons for this, among them suboptimal gross and microscopic assessment of colorectal resection specimens and, later, nonuniformity in applying criteria set forth in pathologic TNM staging guidelines. In addition, some defining characteristics of the staging system remain poorly defined. We aim to enlist those issues with potential remedies to improve reproducibility and, therefore, multidisciplinary discussion.

The topographical distribution of lymph node metastases in colon cancer resections

In accordance with international guidelines all lymph nodes in colon cancer specimens must be examined to obtain accurate staging. This study aimed to determine the topographical location of lymph node metastases and evaluate if a more limited sampling approach could be an alternative. Partial colectomies received at the Department of Pathology, Zealand University Hospital during a six-month period were included. At the macroscopic examination, each specimen was divided into three different segments: a segment containing the index tumor and the tumor-feeding artery, an oral and an anal segment. The number of lymph nodes and lymph node metastases were registered separately for each segment. Resections from 93 patients were included. Of 2466 lymph nodes, 1839 (74.6 %) were located in the tumor segment, 308 (12.5 %) in the oral, and 319 (12.9 %) in the anal segment, respectively. In 133 (5,4 %) lymph nodes a metastasis was present. Of these 129 (97.0 %) were located in the tumor segment, one (0.8 %) in the oral segment, and three (2.3 %) in the anal segment. No patients had metastasis in the oral or anal segments without metastases also being present in the tumor segment leading to consideration of the need for lymph node harvest of the complete specimen upon initial examination. As such, the segment containing the index tumor and tumor-feeding artery could be regarded as a sentinel segment indicating a potential need for lymph node dissection in the oral and anal segments.

Variations in the definition and perceived importance of positive resection margins in patients with colorectal cancer - an EYSAC international survey

INTRODUCTION

Microscopically positive resection margins (R1) are associated with poorer outcomes in patients with colorectal cancer. However, different definitions of R1 margins exist. It is unclear to what extent the definitions used in everyday clinical practice differ within and between nations. This study sought to investigate variations in the definition of R1 margins in colorectal cancer and the importance of margin status in clinical decision-making.

MATERIALS AND METHODS

A 14-point survey was developed by members of The European Society of Surgical Oncology (ESSO) Youngs Surgeons and Alumni Club (EYSAC) Research Academy targeting all members of the multidisciplinary team (MDT) treating patients with colorectal cancer. The survey was distributed on social media, in ESSO's monthly newsletter and via national societies.

RESULTS

In total, 137 responses were received. Most respondents were from Europe (89.7%), with the majority from Denmark (56.9%). Less than 2/3 of respondents defined R1 margins as the presence of viable cancer cells ≤1 mm of the margin. Only 60% reported that subdivisions of R1 margins (primary tumour vs tumour deposit vs metastatic lymph node) are routinely available. More than 20% of respondents reported that pathology reports are not routinely reviewed at MDT meetings. Less than half of respondents considered margin status in decision-making for type and duration of adjuvant chemotherapy in Stage III colon cancer.

CONCLUSION

The definitions and perceived clinical importance of microscopically positive margins in patients with colorectal cancer appear to vary. Adoption of an international dataset for pathology reporting may help to standardise current practices.

Assessment of Elastic Laminal Invasion Contributes to an Objective pT3 Subclassification in Colon Cancer

The extent of tumor spread influences on the clinical outcome, and which determine T stage of colorectal cancer. However, pathologic discrimination between pT3 and pT4a in the eighth edition of the American Joint Committee on Cancer (AJCC)-TNM stage is subjective, and more objective discrimination method for deeply invasive advanced colon cancer is mandatory for standardized patient management. Peritoneal elastic laminal invasion (ELI) detected using elastic staining may increase the objective discrimination of deeply invasive advanced colon cancer. In this study, we constructed ELI study group to investigate feasibility, objectivity, and prognostic utility of ELI. Furthermore, pT classification using ELI was investigated based on these data. At first, concordance study investigated objectivity using 60 pT3 and pT4a colon cancers. Simultaneously, a multi-institutional retrospective study was performed to assess ELI's prognostic utility in 1202 colon cancer cases from 6 institutions. In the concordance study, objectivity, represented by κ, was higher in the ELI assessment than in pT classification. In the multi-institutional retrospective study, elastic staining revealed that ELI was a strong prognostic factor. The clinical outcome of pT3 cases with ELI was significantly and consistently worse than that of those without ELI. pT classification into pT3 without ELI, pT3 with ELI, and pT4a was an independent prognostic factor. In this study, we revealed that ELI is an objective method for discriminating deeply invasive advanced colon cancer. Based on its feasibility, objectivity, and prognostic utility, ELI can subdivide pT3 lesions into pT3a (without ELI) and pT3b (with ELI).

Ibero-American Consensus Review and Incorporation of New Biomarkers for Clinical Practice in Colorectal Cancer

Advances in genomic technologies have significantly improved the management of colorectal cancer (CRC). Several biomarkers have been identified in CRC that enable personalization in the use of biologic agents that have shown to enhance the clinical outcomes of patients. However, technologies used for their determination generate massive amounts of information that can be difficult for the clinician to interpret and use adequately. Through several discussion meetings, a group of oncology experts from Spain and several Latin American countries reviewed the latest literature to provide practical recommendations on the determination of biomarkers in CRC based on their clinical experience. The article also describes the importance of looking for additional prognostic biomarkers and the use of histopathology to establish an adequate molecular classification. Present and future of immunotherapy biomarkers in CRC patients are also discussed, together with several techniques for marker determination, including liquid biopsy, next-generation sequencing (NGS), polymerase chain reaction (PCR), and fecal immunohistochemical tests. Finally, the role of Molecular Tumor Boards in the diagnosis and treatment of CRC is described. All of this information will allow us to highlight the importance of biomarker determination in CRC.

The neoadjuvant rectal score and a novel magnetic resonance imaging based neoadjuvant rectal score are stage independent predictors of long-term outcome in locally advanced rectal cancer

AIM

Neoadjuvant rectal (NAR) score is an early surrogate for longer-term outcomes in rectal cancer undergoing radiotherapy and resection. In an era of increasing organ preservation, resection specimens are not always available to calculate the NAR score. Post-treatment magnetic resonance imaging (MRI) re-staging of regression is subjective, limiting reproducibility. We explored the potential for a novel MRI-based NAR score (mrNAR) adapted from the NAR formula.

METHODS

Locally advanced rectal cancer patients undergoing neoadjuvant therapy (nCRT) and surgery were retrospectively identified between 2008 and 2020 in a single cancer network. mrNAR was calculated by adapting the NAR formula, replacing pathological (p) stages with post-nCRT MR stages (ymr). Cox regression assessed relationships between clinicopathological characteristics, NAR and mrNAR with overall survival (OS) and recurrence-free survival (RFS).

RESULTS

In total, 381 NAR and 177 mrNAR scores were calculated. On univariate analysis NAR related to OS (hazard ratio [HR] 2.05, 95% confidence interval [CI] 1.33-3.14, p = 0.001) and RFS (HR 2.52, 95% CI 1.77-3.59, p = 0.001). NAR 3-year OS <8 was 95.3%, 8-16 was 88.6% and >16 was 80%. mrNAR related to OS (HR 2.96, 95% CI 1.38-6.34, p = 0.005) and RFS (HR 2.99, 95% CI 1.49-6.00, p = 0.002). 3-year OS for mrNAR <8 was 96.2%, 8-16 was 92.4% and >16 was 78%. On multivariate analysis, mrNAR was a stage-independent predictor of OS and RFS. mrNAR corresponded to NAR score category in only 15% (positive predictive value 0.23) and 47.5% (positive predictive value 0.48) of cases for categories <8 and >16, respectively.

CONCLUSIONS

Neoadjuvant rectal score is validated as a surrogate end-point for long-term outcomes. mrNAR categories do not correlate with NAR but have stage-independent prognostic value. mrNAR may represent a novel surrogate end-point for future neoadjuvant treatments that focus on organ preservation.

Tumor budding as a potential prognostic marker in determining the behavior of primary liver cancers

Hepatocellular (HCC) and intrahepatic cholangiocarcinoma (ICC), the most common primary tumors of the liver, are among the most important causes of cancer deaths worldwide. Because patients with primary liver tumors are frequently diagnosed at an advanced stage and have high mortality, many efforts have been made to identify new markers to determine their behavior and treatment, similar to those in other solid organ tumors. Recently, morphological assessment of tumor budding (TB) has been revealed as a promising prognostic finding to predict tumor behavior and survival across several different tumor types. Currently, the TB score in colorectal cancer has been revealed as an important parameter in pathology report protocols to determine the course of the disease. Regarding the liver, despite enormous data showing that many mechanisms involved in TB are associated with tumor behavior in both HCC and ICC, studies focusing on the role of TB in predicting the behavior and prognosis of these tumors have started to be investigated very recently. The purpose of this review is to present data about TB in primary tumors of the liver, pointing out the potential role of this parameter in determining the course of the disease, and emphasize the need to increase the number of further studies focusing on the evaluation of this parameter with an overview of the mechanisms involved in TB.

Minimum standards of pelvic exenterative practice: PelvEx Collaborative guideline

This document outlines the important aspects of caring for patients who have been diagnosed with advanced pelvic cancer. It is primarily aimed at those who are establishing a service that adequately caters to this patient group. The relevant literature has been summarized and an attempt made to simplify the approach to management of these complex cases.

miR-200b, ZEB2 and PTPN13 Are Downregulated in Colorectal Carcinoma with Serosal Invasion

Serosal invasion is an independent negative prognostic factor in certain cancers, including CRC. However, the mechanisms behind serosal invasion are poorly understood. We therefore assumed that epithelial-mesenchymal transition (EMT) might be involved. Our study included 34 patients with CRC, 3 stage pT2, 14 stage pT3 and 17 showing serosal invasion (stage pT4a according to TNM staging system). RNA isolated from formalin-fixed paraffin-embedded tissue samples was analysed for expression of the miR-200 family and their target genes CDKN1B, ONECUT2, PTPN13, RND3, SOX2, TGFB2 and ZEB2 using real-time PCR. We found upregulation of miR-200b and ONECUT2 in CRC pT3 and pT4a compared to normal mucosa, and downregulation of CDKN1B in CRC pT3. Moreover, we observed, downregulation of miR-200b, PTPN13 and ZEB2 in CRC with serosal invasion (pT4a) compared to pT3. Our results suggest the involvement of partial EMT in serosal invasion of CRC. In addition, PTPN13 seems to be one of the important regulators involved in serosal invasion, and ONECUT2 in tumour growth.

Molecular Basis of Extramural Vascular Invasion (EMVI) in Colorectal Carcinoma

BACKGROUND

Extramural vascular invasion (EMVI) is a known poor prognostic factor in colorectal carcinoma; however, its molecular basis has not been defined. This study aimed to assess the expression of molecular markers in EMVI positive colorectal carcinoma to understand their tumor microenvironment.

METHODS

Immunohistochemistry was performed on tissue microarrays of surgically resected colorectal cancer specimens for immunological markers, and BRAFV600E mutation (and on the tissue blocks for mismatch repair proteins). Automated quantification was used for CD8, LAG3, FOXP3, PU1, and CD163, and manual quantification was used for PDL1, HLA I markers (beta-2 microglobulin, HC10), and HLA II. The Wilcoxon rank-sum test was used to compare EMVI positive and negative tumors. A logistic regression model was fitted to assess the predictive effect of biomarkers on EMVI.

RESULTS

There were 340 EMVI positive and 678 EMVI negative chemo naïve tumors. PDL1 was barely expressed on tumor cells (median 0) in the entire cohort. We found a significantly lower expression of CD8, LAG3, FOXP3, PU1 cells, PDL1 positive macrophages, and beta-2 microglobulin on tumor cells in the EMVI positive subset (p ≤ 0.001). There was no association of BRAFV600E or deficient mismatch repair proteins (dMMR) with EMVI. PU1 (OR 0.8, 0.7-0.9) and low PDL1 (OR 1.6, 1.1-2.3) independently predicted EMVI on multivariate logistic regression among all biomarkers examined.

CONCLUSION

There is a generalized blunting of immune response in EMVI positive colorectal carcinoma, which may contribute to a worse prognosis. Tumor-associated macrophages seem to play the most significant role in determining EMVI.

Potential of DEK proto‑oncogene as a prognostic biomarker for colorectal cancer: An evidence‑based review

Given its role in tumorigenesis and its correlation with various pathologic features of colorectal cancer (CRC), DEK is considered to have the potential to predict CRC prognosis. This review attempts to summarize current knowledge and evidence supporting the potential of DEK as a prognostic biomarker of CRC. We searched meta-analyses, systematic reviews, cohort studies, and cell line studies published in the last 10 years. A literature search was conducted in PubMed, Pubmed Central (PMC), Proquest, EBSCOHost, Scopus, and Cochrane Library using the keywords ‘colorectal/colon/rectal cancer’, ‘DEK’, ‘biomarker’, and ‘prognosis’. Studies that were not published in English, without accessible full text, unrelated to clinical questions, or conducted with a design unsuitable for the eligibility criteria were excluded. Seven included studies reported the potential of DEK as a prognostic biomarker of CRC and its role in cancer cell proliferation, invasion, and metastasis. This role is achieved through the Wnt/β-catenin pathway, prevention of apoptosis through destabilization of p53, and bridging inflammation and tumorigenesis through the nuclear factor (NF)-κB pathway, causing chronic inflammation and activation of tumorigenic genes. DEK overexpression is also associated with CRC clinical and pathological features, such as tumor size, lymph node metastasis, serosal invasion, differentiation, tumor staging, and epithelial-mesenchymal transition. DEK overexpression was found to be associated with lower survival and recovery rates. Its prognostic value was comparable with other prognostic biomarkers of CRC, such as BRAF, topoisomerase-1, and CEA. A cohort study reported that DEK overexpression was associated with a better response to fluoropyrimidine-based chemotherapy, while a cell-line study indicated a correlation between DEK overexpression with a worse response to irinotecan-based chemotherapy. In conclusion, considering its correlation with CRC pathology, its association with worse CRC patient survival, and its possibility to forecast the therapeutic response of various chemotherapeutic regimens, DEK has the potential to be used as a CRC prognostic biomarker.

Tumor-Infiltrating Lymphocytes as Biomarkers of Treatment Response and Long-Term Survival in Patients with Rectal Cancer: A Systematic Review and Meta-Analysis

Simple Summary

This study investigated tumor-infiltrating lymphocytes (TILs) in pretherapeutic biopsies as biomarkers of treatment response and long-term prognosis in patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy. A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. The results indicate that it is possible to identify a sub-group of patients with improved treatment response and long-term prognosis by assessing the density of CD8⁺ TILs at the time of diagnosis.

Abstract

Neoadjuvant chemoradiotherapy (NCRT) is indicated in locally advanced rectal cancer (LARC) to downstage tumors before surgery. Watchful waiting may be a treatment option to avoid surgery in patients, obtaining a complete clinical response. However, biomarkers predictive of treatment response and long-term prognosis are lacking. Here we investigated tumor-infiltrating lymphocytes (TILs) in pretherapeutic biopsies as predictive and prognostic biomarkers. A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. In total, 429 articles were identified, of which 19 studies were included in the systematic review and 14 studies in the meta-analysis. Patients with high pretherapeutic CD8⁺ TILs density had an increased likelihood of achieving a pathological complete response (RR = 2.71; 95% CI: 1.58–4.66) or a complete or near-complete pathological treatment response (RR = 1.86; 95% CI: 1.50–2.29). Furthermore, high CD8⁺ TILs density was a favorable prognostic factor for disease-free survival (HR = 0.57; 95% CI: 0.38–0.86) and overall survival (HR = 0.43; 95% CI: 0.27–0.69). CD3⁺, CD4⁺, and FOXP3⁺ TILs were not identified as predictive or prognostic biomarkers. Thus, assessing pretherapeutic CD8⁺ TILs density may assist in identifying patients with increased sensitivity to NCRT and favorable long-term prognosis.

[Standardized structured reports for gastrointestinal tumors]

Synoptic reporting in pathology as opposed to traditional narrative reporting is defined by a laboratory value-like format and use of standardized checklists. It contributes to completeness and comprehensibility of pathology reports and ultimately patient care. As of today, two major institutions publish synoptic reporting templates, the College of American Pathologists (CAP) and the International Collaboration for Cancer Reporting (ICCR). Synoptic protocols are available for all major cancer types and provide not only a standardized terminology and a checklist for completeness of reports, but also facilitate uniform utilization of diagnostic criteria. Additionally, both CAP and ICCR protocols are accompanied by detailed and up-to-date reference lists and thereby represent a valuable source of information even when synoptic reporting is not used. The benefits and challenges of implementation of synoptic reporting are discussed, in particular with regard to reporting in German.