Poorly differentiated clusters (PDCs) as a novel histological predictor of nodal metastases in pT1 colorectal cancer

Prognostic Significance of "High" Tumor Budding and "High" Poorly Differentiated Clusters in Endometrial Carcinomas: Independent Predictors of Lymphovascular Space Invasion and Lymph Node Metastasis

Tumor budding (TB) and poorly differentiated clusters (PDCs) are well-established prognostic factors in various cancers. This study aimed to assess the independent prognostic role of these markers in endometrial carcinomas. Retrospective analysis of endometrial carcinoma resection specimens by examining traditional histologic prognostic parameters. TB and PDC were observed at 20× magnification in ten fields at the invasive front and categorized as present or absent. In addition, a count of ≥5 was stratified as "high." Clinical and follow-up details were extracted from Gynecologic Oncology records. Sixty-five endometrial carcinomas were studied and were predominantly endometrioid (n=47, 72.3%). TB was identified in 52.3% of cases, with high TB observed in 38.5%. PDC was evident in 44.6%, with high PDC seen in 29.2%. Associations were significant between the presence of TB/high TB and higher tumor grade ( P < 0.001), deep myometrial invasion ( P = 0.006/ P = 0.002), diffuse pattern of invasion ( P = 0.007/ P = 0.03), microcystic elongated and fragmented pattern ( P < 0.001), lymphovascular space invasion, lymph node metastasis ( P =<0.001) and International Federation of Gynecology and Obstetrics stage ( P = 0.000/ P = 0.002). PDC/high PDC showed similar associations, and, in addition, with nonendometrioid histologic type ( P = 0.02) and tumor location in a lower uterine segment (high PDC, P = 0.009). After adjusting for other significant parameters, both high TB ( P = 0.03) and high PDC ( P = 0.031) emerged as independent prognostic parameters for lymphovascular space invasion or Lymph node metastasis. No recorded deaths or significant events occurred, precluding commentary on overall survival status. High TB and PDC are independent predictors of Lymph node metastasis in endometrial carcinomas. Their association with the microcystic elongated and fragmented pattern makes them histologic predictors of epithelial-mesenchymal transition. Their simple application underscores their potential as valuable additional prognostic indicators for endometrial carcinomas.

Comparison of the prognosis and lymph node metastasis between no tumor budding and low-grade tumor budding in T1 and T2 colorectal cancer

Tumor budding is a significant prognostic factor in colorectal cancer (CRC) management and is graded as follows: 0-4 buds as low, 5-9 buds as intermediate, and > 10 buds as high. However, the specific prognostic difference between cases with 0 buds (BD0) and those with 1-4 buds (BD1) is not well established owing to a lack of comparative studies. This study aimed to examine and compare the rate of lymph node (LN) metastasis and prognosis by distinguishing between BD0 and BD1 within the low-grade category (0-4 buds) of tumor budding in submucosa (T1) and muscularis propria (T2) CRC. We retrospectively identified 223 cases of T1 and T2 CRC underwent surgery from 2015 to 2018 across three medical institutions using medical records. Pathology, including assessing tumor budding, was subsequently reconfirmed, and the recurrence and survival of patients were evaluated up to December 2023. Patients in the BD1 group exhibited a higher T stage than those in the BD0 group, accompanied by significantly increased rates of lymphovascular and perineural invasion. The prevalence of LN metastasis was 14.8%. No significant differences in LN metastasis were observed between the BD0 and BD1 groups. In a multivariate analysis exploring factors associated with LN metastasis, relevant factors included lymphatic invasion, perineural invasion, and ≥ 5 buds. There were no significant differences in 5-year survival and progression free survival rates between the BD0 and BD1 groups (P = 0.971). This study confirmed that there was no significant difference in LN metastasis or prognosis between patients with BD0 and BD1.

[The phenomenon of tumor budding in gastric cancer]

Gastric cancer remains the fifth most common malignant neoplasm in the world and ranks fifth among the causes associated with cancer. The TNM system remains the gold standard for predictive stratification of patients with gastric cancer, but the search for new sensitive, specific and reproducible biomarkers to develop a personalized approach to the management of patients with gastric cancer does not lose its relevance. The phenomenon of tumor budding is a well-established independent prognostic factor in colorectal cancer. In 2017, the first guideline on the method of calculating tumor budding for colorectal cancer was published. Despite the promising potential of using tumor budding in gastric cancer this parameter is still not evaluated in everyday practice. This lection provides data on various methods of counting tumor budding in gastric carcinomas, describes the molecular mechanisms of interaction between tumor cells and the immune microenvironment, and summarizes the available data on the relationship of clinical and morphological characteristics of gastric cancer with the degree of tumor budding. The relationship between the degree of tumor budding and the prognostic characteristics of gastric cancer and the prospects for its use is also described.

Prognostic value of isolated tumor cells and micrometastasis of lymph nodes in invasive urinary bladder cancer

INTRODUCTION

The prognostic significance of nodal micrometastasis and isolated tumor cells (ITC) in urinary bladder cancer (UBC) is unknown. We aimed to evaluate the prevalence, clinical impact, and clinicopathological characteristics of nodal micrometastasis and ITC in UBC.

MATERIALS AND METHODS

A total of 124 patients with UBC undergoing surgery were investigated. Detection of micrometastasis and ITC was performed using pancytokeratin immunohistochemistry (IHC). Histopathologic and clinical findings were correlated with patients' outcome.

RESULT

IHC detected nodal micrometastasis and ITC (pNmi group) in 12.9% (13/101) of originally node-negative patients and in 26.1% (6/23) of originally node-positive patients (pN+ group). The remaining 88 were truly node-negative patients (pN0 group). After IHC, all 13 patients in the pNmi group were upstaged from pN0 to pN1-2 and one patient in the pN+ group was changed from pN1 to pN2. Nodal micrometastasis and ITC were significantly associated with mixed urothelial carcinoma (UC) (p = 0.002), UC with discohesive pattern (p = 0.006), glandular differentiation (p = 0.043), lymphovascular invasion (p = 0.009), and budding-like tumor cell clusters (p = 0.002). The pNmi group had significantly worse cancer-specific survival than the pN0 group in univariate (p = 0.004) and multivariate (p = 0.040) analysis.

CONCLUSION

IHC frequently identified nodal micrometastasis and ITC in originally node-negative UBC patients on routine pathological examination. Nodal micrometastasis and ITC were independently associated with cancer-related mortality in UBC. IHC might be selectively used to detect micrometastasis and ITC in UBC having specific pathological features.

Local Invasion Patterns Characterized by SARIFA and Tumor Budding Differ and Have Distinct Prognostic Significance in Esophageal Adenocarcinoma and Squamous Cell Carcinoma

Both esophageal squamous cell carcinoma (ESQCC) and adenocarcinoma (EAC) are known to have poor prognosis. We aimed to investigate the invasion front areas of 57 ESQCC and 43 EAC cases to find histological signs of metastatic progression. Tumor cell clusters with different cell counts, including tumor buds (TBs) and poorly differentiated clusters (PDCs), were assessed. The presence of the recently described Stroma AReactive Invasion Front Area (SARIFA) phenomenon, which defines a direct contact between tumor cells and adipocytes, was more frequently observed in EAC than in ESQCC (p = 0.004). In adenocarcinomas, a higher prevalence of SARIFA was observed in tumors with a higher number of small clusters (TBs and small PDCs; p < 0.001); furthermore, both the high number of TBs (p = 0.016) and the presence of SARIFA (p = 0.001) correlated with a higher pT stage. SARIFA positivity in EAC (p = 0.011) and high TB in ESQCC (p = 0.0006) were found to be independent prognostic factors for lymph node metastases. Moreover, in ESQCC, the higher absolute number of both TBs and PDCs was associated with shorter overall survival (p = 0.0269 and p = 0.0377, respectively). Our results suggest that the histological subtypes of esophageal cancer behave differently, namely, that different features of the invasion front are of prognostic significance.

High charge of cerebroid nests in nodular melanomas predicts tumor aggressiveness and high mutational tumoral burden: a pilot study

PURPOSE

Even today, melanoma is a highly aggressive neoplasm with a high mortality rate. The nodular type is very aggressive and has cerebroid nests of melanocytes (CNMs) at the growth edge, morphologically similar to the poorly differentiated neoplastic epithelial cell clusters described in colorectal, breast, and endometrioid endometrial cancers.

PATIENTS AND METHODS

We selected 25 nodular melanomas (NMs) with known molecular profiles, of which the entire paraffin-embedded lesion was available. We counted CNMs under a microscopic at a magnification of 20x (i.e., a microscopic field with a major axis of 1 mm). Based on the number of CNMs in the area, melanomas were classified into three groups: G1 (CNMs ranging from 0 to 4), G2 (CNMs ranging from 5 to 9), and G3 (CNMs ≥ 10). The presence of CNMs and their counts were compared with molecular and histopathological data.

RESULTS

Seventeen (NMs) were grouped as G1 (68%), 5 as G2 (20%), and 3 as G3 (12%) based on CNMs count. The presence of CNMs correlated with epithelioid cell morphology (p < 0.05), Clark IV and V levels (p < 0.05), vascular invasion (p < 0.05), and biological mutants (p < 0.05). Melanomas with ≥ 10 CNMs more frequently show ulceration (p < 0.02) and the BRAF V600E mutation (p < 0.02).

CONCLUSION

CNMs count has a predictive role regardless of tumor size; their association with the BRAF V600E mutation suggests their predictive significance in response to biologics. However, further investigations are needed to strengthen this hypothesis.

Predictors of early colorectal cancer metastasis to lymph nodes: providing rationale for therapy decisions

With the improvement of national health awareness and the popularization of a series of screening methods, the number of patients with early colorectal cancer is gradually increasing, and accurate prediction of lymph node metastasis of T1 colorectal cancer is the key to determining the optimal therapeutic solutions. Whether patients with T1 colorectal cancer undergoing endoscopic resection require additional surgery and regional lymph node dissection is inconclusive in current guidelines. However, we can be sure that in early colorectal cancer without lymph node metastasis, endoscopic resection alone does not affect the prognosis, and it greatly improves the quality of life and reduces the incidence of surgical complications while preserving organ integrity. Therefore, it is vital to discriminate patients without lymph node metastasis in T1 colorectal cancer, and this requires accurate predictors. This paper briefly explains the significance and shortcomings of traditional pathological factors, then extends and states the new pathological factors, clinical test factors, molecular biomarkers, and the risk assessment models of lymph node metastasis based on artificial intelligence.

Additional staining for lymphovascular invasion is associated with increased estimation of lymph node metastasis in patients with T1 colorectal cancer: Systematic review and meta-analysis

OBJECTIVES

Lymphovascular invasion (LVI) is a critical risk factor for lymph node metastasis (LNM), which requires additional surgery after endoscopic resection of T1 colorectal cancer (CRC). However, the impact of additional staining on estimating LNM is unclear. This systematic review aimed to evaluate the impact of additional staining on determining LNM in T1 CRC.

METHODS

We searched five electronic databases. Outcomes were diagnostic odds ratio (DOR), assessed using hierarchical summary receiver operating characteristic curves, and interobserver agreement among pathologists for positive LVI, assessed using Kappa coefficients (κ). We performed a subgroup analysis of studies that simultaneously included a multivariable analysis for other risk factors (deep submucosal invasion, poor differentiation, and tumor budding).

RESULTS

Among the 64 studies (18,097 patients) identified, hematoxylin-eosin (HE) and additional staining for LVI had pooled sensitivities of 0.45 (95% confidence interval [CI] 0.32-0.58) and 0.68 (95% CI 0.44-0.86), specificities of 0.88 (95% CI 0.78-0.94) and 0.76 (95% CI 0.62-0.86), and DORs of 6.26 (95% CI 3.73-10.53) and 6.47 (95% CI 3.40-12.32) for determining LNM, respectively. In multivariable analysis, the DOR of additional staining for LNM (DOR 5.95; 95% CI 2.87-12.33) was higher than that of HE staining (DOR 1.89; 95% CI 1.13-3.16) (P = 0.01). Pooled κ values were 0.37 (95% CI 0.22-0.52) and 0.62 (95% CI 0.04-0.99) for HE and additional staining for LVI, respectively.

CONCLUSION

Additional staining for LVI may increase the DOR for LNM and interobserver agreement for positive LVI among pathologists.

Are the width, length, depth, and area of submucosal invasion predictive of lymph node metastasis in pT1 colorectal cancer?

PURPOSE

Submucosa-limited (pathological T1, pT1) colorectal cancers (CRCs) pose a continuing challenge in the choice of treatment options, which range from local excision to radical surgery. The aim of this study was to evaluate the morphometric and morphologic risk factors associated with regional lymph node metastasis (LNM) in pT1 CRC.

METHODS

We performed a histological review of patients who underwent oncological resection between 2016 and 2022. Tumor grade, budding, poorly differentiated clusters (PDCs), cancer gland rupture, lymphovascular invasion (LVI), and presence of deep submucosal invasion (DSI), as well as width, length, total area, and area of DSI, were evaluated as potential risk factors for LNM.

RESULTS

A total of 264 cases of colon and rectal carcinomas with invasion into the submucosal layer (pT1) were identified. LNM was found in 46 of the 264 cases (17.4%). All morphometric parameters, as well as DSI (P=0.330), showed no significant association with LNM. High grade adenocarcinoma (P=0.050), budding (P=0.056), and PDCs (P<0.001) were associated with LNM. In the multivariate analysis, LVI presence remained the only significant independent risk factor (odds ratio, 15.7; 95% confidence interval, 8.5-94.9; P<0.001).

CONCLUSION

The DSI of T1 CRC, as well as other morphometric parameters of submucosal tumor spread, held no predictive value in terms of LNM. LVI was the only independent risk factor of LNM.

Grades of Poorly Differentiated Clusters are Associated with Lymph Node and the Tumour, Node and Metastasis Stages in Colorectal Carcinoma

Background

Colorectal carcinoma (CRC) is the third most common cancer globally. In Malaysia, CRC is most prevalent among males and the second most common cancer among females. The CRC arises mainly from the adenocarcinoma sequence. Poorly differentiated clusters (PDCs) and tumour budding (TB) are believed to represent sequential steps in tumour growth. Therefore, this study analysed the association between PDC grades with clinicopathological and demographic characteristics of CRC.

Methods

A total of 47 CRC cases previously diagnosed by histopathological examination were reviewed for the presence of PDCs and graded accordingly. The association between PDC grades with clinicopathological and demographic characteristics was statistically analysed.

Results

Out of the 47 cases with PDCs, most of them were of grade 3 (G3) (n = 27, 57.4%), followed by grade 2 (G2) (n = 13, 27.7%) and grade 1 (G1) (n = 7, 14.9%). Higher PDC grades (G2 and G3) were mainly observed in higher tumour stage (T); T3 (n = 26, 83.9%), T4 (n = 12, 92.3%), N1 (n = 20, 86.9%), N2 (n = 15, 100%). In addition, there was a significant association between PDC grades with the nodal stage (N) (P = 0.013) and the tumour, node and metastasis (TNM) stages (P = 0.012).

Conclusion

The PDC grades are useful for assessing the disease prognosis in CRC. A statistically significant association between PDC grades with N and TNM stages suggested that PDC grades are potential predictive parameters for invasive and metastatic risks in CRC.

Lymph Node Molecular Analysis with OSNA Enables the Identification of pT1 CRC Patients at Risk of Recurrence: A Multicentre Study

Early-stage colorectal carcinoma (CRC)-pT1-is a therapeutic challenge and presents some histological features related to lymph node metastasis (LNM). A significant proportion of pT1 CRCs are treated surgically, resulting in a non-negligible surgical-associated mortality rate of 1.5-2%. Among these cases, approximately 6-16% exhibit LNM, but the impact on survival is unclear. Therefore, there is an unmet need to establish an objective and reliable lymph node (LN) staging method to optimise the therapeutic management of pT1 CRC patients and to avoid overtreating or undertreating them. In this multicentre study, 89 patients with pT1 CRC were included. All histological features associated with LNM were evaluated. LNs were assessed using two methods, One-Step Nucleic Acid Amplification (OSNA) and the conventional FFPE plus haematoxylin and eosin (H&E) staining. OSNA is an RT-PCR-based method for amplifying CK19 mRNA. Our aim was to assess the performance of OSNA and H&E in evaluating LNs to identify patients at risk of recurrence and to optimise their clinical management. We observed an 80.9% concordance in LN assessment using the two methods. In 9% of cases, LNs were found to be positive using H&E, and in 24.7% of cases, LNs were found to be positive using OSNA. The OSNA results are provided as the total tumour load (TTL), defined as the total tumour burden present in all the LNs of a surgical specimen. In CRC, a TTL ≥ 6000 CK19 m-RNA copies/µL is associated with poor prognosis. Three patients had TTL > 6000 copies/μL, which was associated with higher tumour budding. The discrepancies observed between the OSNA and H&E results were mostly attributed to tumour allocation bias. We concluded that LN assessment with OSNA enables the identification of pT1 CRC patients at some risk of recurrence and helps to optimise their clinical management.

Colorectal Carcinomas: Searching for New Histological Parameters Associated with Lymph Node Metastases

Background and Objectives: Colorectal cancer (CRC) continues to be an essential public health problem. Our study aimed to evaluate the prognostic significance of classic prognostic factors and some less-studied histopathological parameters in CRC. Materials and Methods: We performed a retrospective study on 71 colorectal carcinoma patients who underwent surgery at the "Pius Brînzeu" County Clinical Emergency Hospital in Timișoara, Romania. We analyzed the classic parameters but also tumor budding (TB), poorly differentiated clusters (PDCs) of cells, tumor-infiltrating lymphocytes (TILs), and the configuration of the tumor border on hematoxylin-eosin slides. Results: A high degree of malignancy (p = 0.006), deep invasion of the intestinal wall (p = 0.003), an advanced stage of the disease (p < 0.0001), lymphovascular invasion (p < 0.0001), perineural invasion (p < 0.0001), high-grade TB (p < 0.0001), high-grade PDCs (p < 0.0001), infiltrative tumor border configuration (p < 0.0001) showed a positive correlation with lymph node metastases. Conclusions: The analyzed parameters positively correlate with unfavorable prognostic factors in CRC. We highlight the value of classic prognostic factors along with a series of less-known parameters that are more accessible and easier to evaluate using standard staining techniques and that could predict the risk of relapse or aggressive evolution in patients with CRC.

Pathological features associated with metastasis in patients with early invasive (pT1) colorectal carcinoma in colorectal polyps

AIMS

Colorectal carcinoma (CRC) arising in a colorectal polyp with invasion limited to the submucosa is sufficiently treated by complete endoscopic resection alone in many cases. Histological features of the carcinoma including tumour size, vascular invasion and poor tumour differentiation or evidence of de-differentiation, such as tumour budding, are associated with a higher risk for metastasis such that oncological resection is recommended. However, most malignant polyps with these features do not have lymph node metastases at the time of resection, so there is a need for better refinement of the histological risk features.

METHODS AND RESULTS

A total of 437 consecutive colorectal polyps with submucosal invasive carcinoma from a single centre, 57 of which had metastatic disease, were supplemented by 30 cases with known metastatic disease from two additional centres. Clinical and histological features of the polyp cancers were reviewed looking for differences between the 87 cancers with metastatic disease and the remaining cases without metastasis. A subgroup of 204 polyps removed intact was also analysed to ensure maximum histological accuracy.

CONCLUSIONS

This study confirmed larger invasive tumour size, vascular invasion and poor tumour differentiation as adverse predictive features. Prominent peritumoral desmoplasia and high cytological grade were additional adverse features. A predictive logistic regression model comprised of (i) presence of any form of vascular invasion; (ii) presence of high tumour budding (BD3); (iii) width of invasive tumour component > 8 mm; (iv) depth of invasive tumour > 1.5 mm; and (v) the finding of prominent expansile desmoplasia located within and beyond the deep invasive edge of the carcinoma, showed excellent performance in predicting metastatic disease.

Tumor budding in breast carcinoma: A systematic review and meta-analysis

ABSTRACT

Tumor budding is gaining importance as a prognostic factor in various carcinomas due to its association with epithelial-mesenchymal transition (EMT) and hence clinical outcome. Reporting tumor budding in breast cancer lacks homogeneity. We aim to systematically review the existing literature and conduct a meta-analysis to assess the prognostic implication of tumor budding in breast carcinoma. A systematic search was performed to identify studies that compared different prognostic variables between high- and low-grade tumor budding. Quality assessment was performed using a modified Newcastle Ottawa Scale. Dichotomous variables were pooled using the odds ratio using the Der-Simonian-Laird method. Meta-analysis was conducted to study the association between low/high-grade tumor budding and tumor grade, lymph node metastasis, lymphovascular invasion, ER, PR, HER2neu, KI67, and the molecular subtype triple-negative breast carcinoma. Thirteen studies with a total of 1763 patients were included. A moderate risk of bias was noted. The median bias scoring was 7 (6-9). High-grade tumor budding was significantly associated with lymph node metastasis (OR: 2.25, 95% CI: 1.52-3.34, P < 0.01) and lymphovascular invasion (OR: 3.14, 95% CI: 2.10-4.71, P < 0.01), and low-grade budding was significantly associated with triple-negative breast carcinoma (OR: 0.61, 95% CI: 0.39-0.95, P = 0.03)There was significant heterogeneity in the assessment and grading of tumor budding; thus, a checklist of items was identified that lacked standardization. Our meta-analysis concluded that tumor budding can act as an independent prognostic marker for breast cancer.

New Histoprognostic Factors to Consider for the Staging of Colon Cancers: Tumor Deposits, Invasive Tumor Infiltration and High-Grade Budding

Colorectal cancer is a major public health issue due to its high incidence and mortality. It is, therefore, essential to identify histological markers for prognostic purposes and to optimize the therapeutic management of patients. The main objective of our study was to analyze the impact of new histoprognostic factors, such as tumor deposits, budding, poorly differentiated clusters, mode of infiltration, the intensity of inflammatory infiltrate and the type of tumor stroma, on the survival of patients with colon cancer. Two hundred and twenty-nine resected colon cancers were fully histologically reviewed, and survival and recurrence data were collected. Survival was analyzed using Kaplan-Meier curves. A univariate and multivariate Cox model was constructed to identify prognostic factors for overall survival and recurrence-free survival. The median overall survival of the patients was 60.2 months and the median recurrence-free survival was 46.9 months. Overall survival and recurrence-free survival were significantly worse in the presence of isolated tumor deposits (log rank = 0.003 and 0.001, respectively) and for an infiltrative type of tumor invasion (log rank = 0.008 and 0.02, respectively). High-grade budding was associated with a poor prognosis, with no significant difference. We did not find a significant prognostic impact of the presence of poorly differentiated clusters, the intensity of the inflammatory infiltrate or the stromal type. In conclusion, the analysis of these recent histoprognostic factors, such as tumor deposits, mode of infiltration, and budding, could be integrated into the results of pathological reports of colon cancers. Thus, the therapeutic management of patients could be adjusted by providing more aggressive treatments in the presence of some of these factors.

Tumour budding and poorly differentiated clusters in colon cancer - different manifestations of partial epithelial-mesenchymal transition

Morphological features including infiltrative growth, tumour budding (TB), and poorly differentiated clusters (PDCs) have a firmly established negative predictive value in colorectal cancer (CRC). Despite extensive research, the mechanisms underlying different tumour growth patterns remain poorly understood. The aim of this study was to investigate the involvement of epithelial-mesenchymal transition (EMT) in TB and PDCs in CRC. Using laser-capture microdissection, we obtained distinct parts of the primary CRC including TB, PDCs, expansive tumour front, and the central part of the tumour, and analysed the expression of EMT-related markers, i.e. the miR-200 family, ZEB1/2, RND3, and CDH1. In TB, the miR-200 family and CDH1 were significantly downregulated, while ZEB2 was significantly upregulated. In PDCs, miR-141, miR-200c, and CDH1 were significantly downregulated. No significant differences were observed in the expression of any EMT-related markers between the expansive tumour front and the central part of the tumour. Our results suggest that both TB and PDCs are related to partial EMT. Discrete differences in morphology and expression of EMT-related markers between TB and PDCs indicate that they represent different manifestations of partial EMT. TB seems to be closer to complete EMT than PDCs. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Prognostic Ability of Tumor Budding Outperforms Poorly Differentiated Clusters in Gastric Cancer

The prognostic value of histological phenomena tumor budding (TB) and poorly differentiated clusters (PDCs) have been less studied in gastric cancer (GAC) and the data provided so far are controversial. In our study, 290 surgically resected GAC cases were evaluated for TB according to the criteria of International Tumor Budding Consensus Conference (ITBCC) and PDC, and both parameters were scored on a three-grade scale as described for colorectal cancer previously (0: Grade0, 1-4: Grade1, 5-9: Grade2 and ≥10: Grade3) and classified as low (Grade0-2) and high (Grade3) TB/PDC. High TB/PDC was associated with diffuse-type morphology, higher pT status, incomplete surgical resection, poor tumor differentiation and perineural and lymphovascular invasion. Multivariable survival analyses have shown an independent prognostic role of high TB with poorer overall survival in the total cohort (p = 0.014) and in intestinal-type adenocarcinomas (p = 0.005). Multivariable model revealed high TB as an independent predictor for lymph node metastasis in both the total cohort (p = 0.019) and in the intestinal type adenocarcinomas (p = 0.038). In contrast to tumor budding, no significant association was found between PDC and the occurrence of lymph node metastasis and tumor stage and even survival. In conclusion, tumor budding is an independent prognostic factor of survival in gastric cancer, especially in intestinal-type adenocarcinomas.

Poorly differentiated cluster grade-a vital predictor for lymph node metastasis and oncological outcomes in patients with T1 colorectal cancer: a retrospective study

Background

T1 colorectal cancers have a low lymph node metastasis rate and good prognosis. Thus, endoscopic resection is an attractive choice. This study aimed to describe the value of poorly differentiated cluster grade in identifying endoscopically curable T1 colorectal cancers.

Methods

We included 183 T1 colorectal cancer patients who underwent curative resection. Univariate and multivariate logistic regressions were used to identify lymph node metastasis predictors. The Akaike information criterion was used to determine whether poorly differentiated cluster grade was the best predictor. Backward regression was used to screen the variables. Survival analyses were conducted to determine the prognostic predictive power of poorly differentiated cluster grade. Correlations among predictors and concordance between our pathologists were also investigated.

Results

Poorly differentiated cluster grade was an independent predictor for lymph node metastasis (adjusted odds ratio [OR]_{G 3} = 0.001; 95% confidence interval [95% CI]_{G 3} =  < 0.001, 0.139) in T1 colorectal cancer patients; moreover, it had the best predictive value (AIC = 61.626) among all indicators. It was also screened for inclusion in the predictive model. Accordingly, a high poorly differentiated cluster grade independently indicated shorter overall survival (hazard ratio [HR]_{G 2} = 4.315; 95% CI_{G 2} = 1.506, 12.568; HR_{G 3} = 5.049; 95% CI_{G 3} = 1.326, 19.222) and disease-free survival (HR_{G 3} = 6.621; 95% CI_{G 3} = 1.472, 29.786).

Conclusions

Poorly differentiated cluster grade is a vital reference to manage T1 colorectal cancer. It could serve as an indicator to screen endoscopically curable T1 colorectal cancers.

Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection

Current histopathological staging procedures in colorectal cancer (CRC) depend on midline division of the lymph nodes (LNs) with one section of hematoxylin and eosin staining. Cancer cells outside this transection line may be missed, which could lead to understaging of Union for International Cancer Control Stage II high-risk patients. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid molecular diagnostic tool for LN metastases detection. It is a molecular technique that can analyze the entire LN tissue using a reverse-transcriptase loop-mediated isothermal amplification reaction to detect tumor-specific cytokeratin 19 mRNA. Our findings suggest that the OSNA assay has a high diagnostic accuracy in detecting metastatic LNs in CRC and a high negative predictive value. OSNA is a standardized, observer-independent technique, which may lead to more accurate staging. It has been suggested that in stage II CRC, the upstaging can reach 25% and these patients can access postoperative adjuvant chemotherapy. Moreover, intraoperative OSNA sentinel node evaluation may allow early CRC to be treated with organ-preserving surgery, while in more advanced-stage disease, a tailored lymphadenectomy can be performed considering the presence of aberrant lymphatic drainage and skip metastases.

Current problems and perspectives of pathological risk factors for lymph node metastasis in T1 colorectal cancer: Systematic review

With the prevalence of endoscopic submucosal dissection and endoscopic full thickness resection, which enable complete resection of T1 colorectal cancer with a negative margin, the treatment strategy following endoscopic resection has become more important. The necessity of secondary surgical resection is determined on the basis of the risk of lymph node metastasis according to the histopathological findings of resected specimens because ~10% of T1 colorectal cancer cases have lymph node metastasis. The current Japanese treatment guidelines state four risk factors for lymph node metastasis: lymphovascular invasion, histological differentiation, depth of submucosal invasion, and tumor budding. These guidelines have succeeded in stratifying the low-risk group for lymph node metastasis, in which endoscopic resection alone is acceptable for cure. On the other hand, there are some problems: there is variation in diagnosis methods and low interobserver agreement for each pathological factor and 90% of surgical resections are unnecessary, with lymph node metastasis negativity. To ensure patients with T1 colorectal cancer receive more appropriate treatment, these problems should be addressed. In this systematic review, we gave some suggestions to these practical issues of four pathological factors as predictors.

Deep Submucosal Invasion Is Not an Independent Risk Factor for Lymph Node Metastasis in T1 Colorectal Cancer: A Meta-Analysis

BACKGROUND & AIMS

Deep submucosal invasion (DSI) is considered a key risk factor for lymph node metastasis (LNM) and important criterion to recommend surgery in T1 colorectal cancer. However, metastatic risk for DSI is shown to be low in the absence of other histologic risk factors. This meta-analysis determines the independent risk of DSI for LNM.

METHODS

Suitable studies were included to establish LNM risk for DSI in univariable analysis. To assess DSI as independent risk factor, studies were eligible if risk factors (eg, DSI, poor differentiation, lymphovascular invasion, and high-grade tumor budding) were simultaneously included in multivariable analysis or LNM rate of DSI was described in absence of poor differentiation, lymphovascular invasion, and high-grade tumor budding. Odds ratios (OR) and 95% CIs were calculated.

RESULTS

Sixty-seven studies (21,238 patients) were included. Overall LNM rate was 11.2% and significantly higher for DSI-positive cancers (OR, 2.58; 95% CI, 2.10-3.18). Eight studies (3621 patients) were included in multivariable meta-analysis and did not weigh DSI as a significant predictor for LNM (OR, 1.73; 95% CI, 0.96-3.12). As opposed to a significant association between LNM and poor differentiation (OR, 2.14; 95% CI, 1.39-3.28), high-grade tumor budding (OR, 2.83; 95% CI, 2.06-3.88), and lymphovascular invasion (OR, 3.16; 95% CI, 1.88-5.33). Eight studies (1146 patients) analyzed DSI as solitary risk factor; absolute risk of LNM was 2.6% and pooled incidence rate was 2.83 (95% CI, 1.66-4.78).

CONCLUSIONS

DSI is not a strong independent predictor for LNM and should be reconsidered as a sole indicator for oncologic surgery. The expanding armamentarium for local excision as first-line treatment prompts serious consideration in amenable cases to tailor T1 colorectal cancer management.

Role of poorly differentiated cluster in gastric cancer: is it a new prognosis factor?

BACKGROUND

Poorly differentiated Clusters (PDCs) of tumor cells composed of more than five elements have been recently described in gastrointestinal cancers and correlate with a worse prognosis. Our study aims to investigate PDC occurrence in a series of patients with gastric cancer and correlate it with lymph node status and clinical outcome.

MATERIAL AND METHODS

50 patients were included in the study; PDCs count was graduated as G1, G2, and G3 according to Ueno classification (PDCs count at 20× <5, 5-9 and ≥10 respectively). We collected several clinicopathologic variables such as tumor location, pTNM stage, vascular or perineural invasion, and lymph-node ratio for each case.

RESULTS

The presence of PDCs was related to vascular invasion (p < .013) and recurrence event (p < .027). When the population was categorized according to the number of PDCs, a significant correlation was found with the presence of lymph node metastasis (p < .000), the Lymph Node Ratio (p < .002), WHO stage at the diagnosis (p < .000) and vascular invasion (p < .001). At the univariate and multivariate analysis, PDCs were found as an independent risk factor for recurrence (HR 1.94; CI 95% 1.209-3.121; p < .006 and HR 0.401; CI 95% 0.187-0.862; p < .017 respectively). The Kaplan-Meier curves for OS and DFS showed a significant association between PDCs and shorter time to recurrence or survival.

CONCLUSION

PDC is a strong prognostic factor in gastric cancer, easily detectable, and feasible. As far as we know, this is the first report in Literature of a strong correlation between PDC and survival in patients with operated gastric cancer.

Classic and Novel Histopathologic Risk Factors for Lymph Node Metastasis in T1 Colorectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Treatment of endoscopically resected T1 colorectal cancers is based on the risk of lymph node metastasis. Risk is based on histopathologic features, although there is lack of consensus as to what constitutes high-risk features.

OBJECTIVE

The purpose of this study was to conduct a systematic review and meta-analysis of histopathologic risk factors for lymph node metastasis.

DATA SOURCES

A search of MEDLINE, Embase, Scopus, and Cochrane controlled register of trials for risk factors for lymph node metastasis was performed from inception until August 2018.

STUDY SELECTION

Included patients must have had an oncologic resection to confirm lymph node status and reported at least 1 histopathologic risk factor.

INTERVENTION

Rates of lymph node positivity were compared between patients with and without risk factors.

MAIN OUTCOME MEASURES

We report the results of the meta-analysis as ORs.

RESULTS

Of 8592 citations, 60 met inclusion criteria. Pooled analyses found that lymphovascular invasion, vascular invasion, neural invasion, and poorly differentiated histology were significantly associated with lymph node metastasis, as were depths of 1000 µm (OR = 2.76), 1500 µm (OR = 4.37), 2000 µm (OR = 2.37), submucosal level 3 depth (OR = 3.08), and submucosal level 2/3 (OR = 3.08) depth. Depth of 3000 µm, Haggitt level 4, and widths of 3000 µm and 4000 µm were not significantly associated with lymph node metastasis. Tumor budding (OR = 4.99) and poorly differentiated clusters (OR = 14.61) were also significantly associated with lymph node metastasis.

LIMITATIONS

Included studies reported risk factors independently, making it impossible to examine the additive metastasis risk in patients with numerous risk factors.

CONCLUSIONS

We identified 1500 μm as the depth most significantly associated with lymph node metastasis. Novel factors tumor budding and poorly differentiated clusters were also significantly associated with lymph node metastasis. These findings should help inform guidelines regarding risk stratification of T1 tumors and prompt additional investigation into the exact contribution of poorly differentiated clusters to lymph node metastasis.

Cytoproliferative activity in colorectal poorly differentiated clusters: Biological significance in tumor setting

BACKGROUND

Poorly differentiated clusters (PDCs) have gained a significant prognostic role in colorectal carcinomas (CRCs) being associated to high risk of lymph node metastasis, shorter survival time and poor prognosis. The knowledge in PDC biology is not completely clear.

MATERIALS AND METHODS

We assessed Ki-67 LI in 45 CRCs showing ≥10 PDCs. We distinguished PDCs at the periphery of the tumor masses (pPDCs) from those within the tumor masses (cPDCs). We chose 3 cut-offs of Ki-67 labeling index (Ki-67 LI): <10%, 10-50%, and >50% of the labeled cells.

RESULTS

Ki-67 LI in pPDCs was<10% in 37 cases (82%), 10-50% in 6 cases (13%) and >50%in 2 cases (5%); Ki-67 LI in cPDCs was<10% in 4 cases (23.5%), 10-50% in 4 (23.5%) and >50% in 9 (54%). Ki-67 LI in tumor budding foci (TBs) was <10% in 8 cases (32%), 10-50% in 8 (32%) and >50% in 9 (36%). The difference of Ki-67 LI reaches the statistical significance (p < 0.005). Ki-67 LI <10% in the pPDCs was associated with nodal metastases (pN+) (p < 0.0001), pTNM stage III and IV(p < 0.0001) and TB (p < 0.001). Ki-67 LI > 50% in cPDC was significantly associated withpT3-pT4 and advanced pTNM stages (p < 0.0001), N+ (p = 0.0001) and LVI (p < 0.05).

CONCLUSION

Different Ki-67 LI detected between cPDCs and pPDCs suggesting a biological difference in PDCs. An actively proliferating central tumor areas can be distinguished from the peripheral portion of the tumors in which the cells interact with the stroma acquiring invasive and metastatic potential.

Association Between Obesity and Histological Tumor Budding in Patients With Nonmetastatic Colon Cancer

IMPORTANCE

Obesity is associated with increased risk of colorectal cancer (CRC) and a more aggressive disease course. Tumor budding (TB) is an important prognostic factor for CRC, but its association with obesity is unknown.

OBJECTIVE

To evaluate the association of TB with obesity and other prognostic factors in colon cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study involved a histological review of colon cancer specimens obtained during 7 years (January 2008 to December 2015) at the University of Kentucky Medical Center; data analysis was conducted from February 2020 to January 2021. Specimens came from 200 patients with stage I to III colon cancer; patients with stage 0, stage IV, or incomplete data were excluded.

MAIN OUTCOMES AND MEASURES

TB was defined as 1 to 4 malignant cells at the invasive edge of the tumor, independently assessed by 2 academic pathologists. The primary outcome was the association of TB with obesity (defined as body mass index [BMI] of 30 or greater). Secondary outcomes include the association of TB with clinical features (ie, age, race, sex, TNM stage, tumor location) and pathological features (ie, poorly differentiated tumor clusters [PDCs], Klintrup-Mäkinen inflammatory score, desmoplasia, infiltrative tumor border, tumor necrosis, and tumor-to-stroma ratio).

RESULTS

A total of 200 specimens were reviewed. The median (interquartile range) age of patients was 62 (55-72) years, 102 (51.0%) were women, and the mean (SD) BMI was 28.5 (8.4). A total of 57 specimens (28.5%) were from stage I tumors; 74 (37.0%), stage II; and 69 (34.5%), stage III. Of these, 97 (48.5%) had low-grade (<5 buds), 36 (18.0%) had intermediate-grade (5-9 buds), and 67 (33.5%) had high-grade (≥10 buds) TB. Multivariable analysis adjusting for clinical and histological factors demonstrated that higher TB grade was associated with obesity (odds ratio [OR], 4.25; 95% CI, 1.95-9.26), higher PDC grade (grade 2 vs 1: OR, 9.14; 95% CI, 3.49-23.93; grade 3 vs 1: OR, 5.10; 95% CI, 2.30-11.27), increased infiltrative tumor border (OR, 1.03; 95% CI, 1.01-1.04), cecal location (OR, 2.55; 95% CI, 1.09-5.97), and higher stage (eg, stage III vs stage I for high-grade or intermediate-grade vs low-grade TB: OR, 2.91; 95% CI, 1.00-8.49). Additionally, patients with a higher TB grade had worse overall survival (intermediate vs low TB: hazard ratio, 2.20; 95% CI, 1.11-4.35; log-rank P = .02; high vs low TB: hazard ratio, 2.67; 95% CI, 1.45-4.90; log-rank P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study, a novel association between high TB grade and obesity was found. The association could reflect a systemic condition (ie, obesity) locally influencing aggressive growth (ie, high TB) in colon cancer.

Lymph Node Tumor Burden Correlates With Tumor Budding and Poorly Differentiated Clusters: A New Prognostic Factor in Colorectal Carcinoma?

INTRODUCTION

Molecular lymph node (LN) staging in early colorectal cancer (CRC) has demonstrated to be more precise than conventional histopathology pN staging. Tumor budding (TB) and poorly differentiated clusters (PDCs) are associated with LN metastases, recurrences, and lower survival in CRC. We evaluated the correlation between the total tumor load (TTL) in LNs from CRC surgical specimens with patient outcome, TB, and PDC.

METHODS

In this retrospective multicentre study, 5,931 LNs from 342 stage I-III CRC were analyzed by both hematoxylin and eosin and molecular detection of tumor cytokeratin 19 mRNA by one-step nucleic acid amplification. TB and PDC were evaluated by hematoxylin and eosin and cytokeratin 19 immunohistochemistry.

RESULTS

One-step nucleic acid was positive in 38.3% patients (n = 131). Tumor Budding was low in 45% cases, intermediate in 25%, and high in 30%. Poorly Differentiated Clusters were low-grade G1 in 53%, G2 in 32%, and G3 in 15%. TB and PDC correlated with TTL, high-grade, lymphovascular and perineural invasion, pT, pN and stage (P < 0.001). TB, PDC, and TTL ≥ 6,000 copies/µL were associated with worse overall survival (P = 0.002, P = 0.013, and P = 0.046) and disease-free survival (P < 0.001).

DISCUSSION

The implementation of more sensitive molecular methods to assess LN status is a promising alternative approach to pN staging, which could be integrated to other factors to help risk stratification and management of patients with early-stage CRC. This study demonstrates the correlation of the amount of LN tumor burden with TB and PDCs. TTL is related to the outcome and could be used as a new prognostic factor in CRC (see Visual Abstract, Supplementary Digital Content 2, http://links.lww.com/CTG/A512).

Prognostic impact of tumor budding and EMT in periampullary adenocarcinoma: a quantitative approach

The presence of invasive cell clusters known as tumor budding and the closely related epithelial mesenchymal transition (EMT) have a prognostic impact on cancer patients' overall survival. Interestingly, data quantitatively analyzing and correlating the amount of tumor buds and patient overall survival as well as the impact of expression of epithelial phenotype markers are missing. Periampullary carcinoma samples of 171 patients were immunohistochemically stained for E-Cadherin (ECad). Tumor cell clusters (TCC, defined from one to 50 cells) were manually quantified comprising tumor cell number and subcellular localization of ECad expression (membranous, cytoplasmic or mixed). Data analyses were performed using elastic net feature selection. Hereby, five distinct intervals of TCC sizes and corresponding fractions of cells with distinct ECad expression were identified. Prognostic features of the defined budding categories were entered into a subsequent Cox regression model together with standard clinicopathological parameters and, based on the model prediction, cases were categorized into "low and high budding" grades. Overall median TCC size was 16 cells (range: 2-36 cells). The median number of TCCs per tumor was 42 (range: 3-283). Elastic net feature selection identified TCCs of 6-10 and 31-35 cells as prognostically most relevant negative and positive features, respectively. Regarding ECad expression, cytoplasmic ECad expression in TCCs of 11-15 as well as of 26-30 cells revealed prognostic relevance. Combining TCC numbers and ECad expression, budding grade qualified as independent prognostic factor for patient overall survival (p<0.001) in a multivariable clinicopathologic Cox model. Applying an advanced modelling by machine learning on a cohort of periampullary cancers, we show that not the smallest TCCs (1-5 cells) but tumor cell nests containing 6-10 cells display the strongest negative prognostic relevance. Moreover, we demonstrate that larger TCCs might have a strong positive prognostic impact in periampullary adenocarcinomas, contributing to establishing an advanced grading system.

Poorly differentiated clusters in colorectal cancer: a current review and implications for future practice

Poorly differentiated clusters (PDC), defined as small groups of ≥5 tumour cells without glandular differentiation, have gained recent attention as a promising prognostic factor in colorectal cancer (CRC). Numerous studies have shown PDC to be significantly associated with other adverse histopathological features and worse clinical outcomes. PDC may hold particular promise in stage II colon cancer, where risk stratification plays a critical role in patient selection for adjuvant chemotherapy. In addition, emerging evidence suggests that PDC can predict lymph node metastasis in endoscopically resected pT1 CRC, potentially helping the selection of patients for oncological resection. In 'head-to-head' comparisons, PDC grade has consistently outperformed conventional histological grading systems both in terms of risk stratification and reproducibility. With a number of large-scale studies now available, this review evaluates the evidence regarding the prognostic significance of PDC, considers its relationship with other emerging invasive front prognostic markers (such as tumour budding and stroma type), assesses its 'practice readiness', addressing issues such as interobserver reproducibility, scoring methodologies and special histological subtypes (e.g. micropapillary and mucinous carcinoma), and draws attention to ongoing challenges and areas in need of further study. Finally, emerging data on the role of PDC in non-colorectal cancers are briefly considered.

Adverse Histologic Features in Colorectal Nonpedunculated Malignant Polyps With Nodal Metastasis

Tumor differentiation, lymphovascular invasion, margin status, polyp shape, and size are important parameters of malignant polyps (pT1) indicating possible node metastasis, which justifies a surgery. However, the size, margin, and lymphovascular invasion are often unknown or difficult to assess in a piecemeal polypectomy from a nonpedunculated malignant polyp. The aim of the study was to identify adverse histologic features in nonpedunculated malignant polyps associated with an increased risk of nodal metastasis, which may warrant a colectomy procedure. A total of 24 node-positive and 18 node-negative nonpedunculated malignant polyps and their corresponding subsequent resection specimens from 2005 to 2018 were reviewed. Cases with node metastasis were more often positive for high-grade tumor budding (70.8% vs. 16.7%; P=0.0005), poorly differentiated clusters (54.2% vs. 22.2%; P=0.0369), and both high-grade tumor budding and poorly differentiated clusters (45.8% vs. 11.1%; P=0.0160) compared with controls without nodal metastasis. High-grade tumor budding, poorly differentiated clusters, and combined high-grade tumor budding and poorly differentiated clusters increased the risk of nodal metastasis, with odds ratio of 12.1, 4.1, and 14.3, respectively. Furthermore, nodal metastasis could be seen in subsequent colectomy specimen even in completely excised malignant polyps with adverse histologic features. Our findings indicate that high-grade tumor budding and poorly differentiated clusters are important adverse histologic risk features in predicting lymph node metastatic potential. These histologic features should be reported and it may warrant a colectomy when they are present.

Clinicopathological significance of heterogeneic ezrin expression in poorly differentiated clusters of colorectal cancers

Multicellular structures, such as tumor buddings and poorly differentiated clusters (PDC), exist at the invasive front of colorectal cancers (CRC). Although it has been reported that CRC with PDC showed frequent lymph node metastases with a worse prognosis, the molecular markers of PDC that are responsible for prognosis have not been identified. We here noticed for the first time that Ezrin, a regulator of the actin cytoskeleton, is expressed in the corner cells of PDC. We then aimed to verify whether heterogeneous Ezrin expression in PDC predicts the prognosis of CRC patients. We immunohistochemically analyzed Ezrin expression in PDC of 184 patients with completely resected stages I-III CRC. We established the Ezrin corner score (ECS), which quantifies the tendency of Ezrin-positive cells to accumulate at the corners of PDC. On the basis of ECS values, 2 indices, the mean ECS and the number of PDC with high ECS, were obtained. Both indices were significantly higher in CRC with lymphatic invasion, higher PDC grade, and presence of micropapillary (MP) PDC. The mean ECS-high group showed shorter recurrence-free survival than the mean ECS-low group but without significance. The other index, the number of ECS-high PDC, was significantly associated with recurrence-free survival. These results suggest that Ezrin is involved in PDC progression and lymphatic invasion, and that ECS may be a marker for aggressive PDC.

Tumor Budding in Colorectal Carcinoma: Translating a Morphologic Score Into Clinically Meaningful Results

CONTEXT

- Tumor budding has received increasing recognition as an important independent prognostic factor in colorectal carcinoma. Prominent tumor budding in adenocarcinoma arising in a polyp has been shown to be a risk factor for lymph node involvement. The variability in methods used for evaluating tumor budding in different studies and lack of standardized guidelines have impeded routine inclusion of tumor budding in pathology reports. This changed last year with consensus guidelines based on the International Tumor Budding Consensus Conference (ITBCC). These guidelines have been included in the recent College of American Pathologists (CAPs) Colorectal Cancer Protocol. The consensus methodology will allow uniform reporting of this finding, but challenges in interpretation in the setting of intense inflammation, fibrosis, or gland fragmentation need to be addressed in future guidelines.

OBJECTIVE

- To provide a brief overview of the known clinical significance of tumor budding in colorectal carcinoma and discuss the practical aspects of its implementation on a routine basis.

DATA SOURCES

- English-language pathology literature.

CONCLUSIONS

- Tumor budding has been shown to be an independent prognostic marker in colorectal carcinomas and the routine reporting of tumor buds is now advocated by using the approach outlined by the ITBCC guidelines. Tumor budding is included in the CAP protocol as a recommended element. Presence of prominent tumor budding in an adenocarcinoma in a polyp may have implications for management, such as additional resection, while it serves as a prognostic factor in other settings.

Histologic Factors Associated With Need for Surgery in Patients With Pedunculated T1 Colorectal Carcinomas

BACKGROUND & AIMS

Most patients with pedunculated T1 colorectal tumors referred for surgery are not found to have lymph node metastases, and were therefore unnecessarily placed at risk for surgery-associated complications. We aimed to identify histologic factors associated with need for surgery in patients with pedunculated T1 colorectal tumors.

METHODS

We performed a cohort-nested matched case-control study of 708 patients diagnosed with pedunculated T1 colorectal tumors at 13 hospitals in The Netherlands, from January 1, 2000 through December 31, 2014, followed for a median of 44 months (interquartile range, 20-80 months). We identified 37 patients (5.2%) who required surgery (due to lymph node, intramural, or distant metastases). These patients were matched with patients with pedunculated T1 colorectal tumors without a need for surgery (no metastases, controls, n = 111). Blinded pathologists analyzed specimens from each tumor, stained with H&E. We evaluated associations between histologic factors and patient need for surgery using univariable conditional logistic regression analysis. We used multivariable least absolute shrinkage and selection operator (LASSO; an online version of the LASSO model is available at: http://t1crc.com/calculator/) regression to develop models for identification of patients with tumors requiring surgery, and tested the accuracy of our model by projecting our case-control data toward the entire cohort (708 patients). We compared our model with previously developed strategies to identify high-risk tumors: conventional model 1 (based on poor differentiation, lymphovascular invasion, or Haggitt level 4) and conventional model 2 (based on poor differentiation, lymphovascular invasion, Haggitt level 4, or tumor budding).

RESULTS

We identified 5 histologic factors that differentiated cases from controls: lymphovascular invasion, Haggitt level 4 invasion, muscularis mucosae type B (incompletely or completely disrupted), poorly differentiated clusters and tumor budding, which identified patients who required surgery with an area under the curve (AUC) value of 0.83 (95% confidence interval, 0.76-0.90). When we used a clinically plausible predicted probability threshold of ≥4.0%, 67.5% (478 of 708) of patients were predicted to not need surgery. This threshold identified patients who required surgery with 83.8% sensitivity (95% confidence interval, 68.0%-93.8%) and 70.3% specificity (95% confidence interval, 60.9%-78.6%). Conventional models 1 and 2 identified patients who required surgery with lower AUC values (AUC, 0.67; 95% CI, 0.60-0.74; P = .002 and AUC, 0.64; 95% CI, 0.58-0.70; P < .001, respectively) than our LASSO model. When we applied our LASSO model with a predicted probability threshold of ≥4.0%, the percentage of missed cases (tumors mistakenly assigned as low risk) was comparable (6 of 478 [1.3%]) to that of conventional model 1 (4 of 307 [1.3%]) and conventional model 2 (3 of 244 [1.2%]). However, the percentage of patients referred for surgery based on our LASSO model was much lower (32.5%, n = 230) than that for conventional model 1 (56.6%, n = 401) or conventional model 2 (65.5%, n = 464).

CONCLUSIONS

In a cohort-nested matched case-control study of 708 patients with pedunculated T1 colorectal carcinomas, we developed a model based on histologic features of tumors that identifies patients who require surgery (due to high risk of metastasis) with greater accuracy than previous models. Our model might be used to identify patients most likely to benefit from adjuvant surgery.

Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016

Tumor budding is a well-established independent prognostic factor in colorectal cancer but a standardized method for its assessment has been lacking. The primary aim of the International Tumor Budding Consensus Conference (ITBCC) was to reach agreement on an international, evidence-based standardized scoring system for tumor budding in colorectal cancer. The ITBCC included nine sessions with presentations, a pre-meeting survey and an e-book covering the key publications on tumor budding in colorectal cancer. The 'Grading of Recommendation Assessment, Development and Evaluation' method was used to determine the strength of recommendations and quality of evidence. The following 10 statements achieved consensus: tumor budding is defined as a single tumor cell or a cell cluster consisting of four tumor cells or less (22/22, 100%). Tumor budding is an independent predictor of lymph node metastases in pT1 colorectal cancer (23/23, 100%). Tumor budding is an independent predictor of survival in stage II colorectal cancer (23/23, 100%). Tumor budding should be taken into account along with other clinicopathological features in a multidisciplinary setting (23/23, 100%). Tumor budding is counted on H&E (19/22, 86%). Intratumoral budding exists in colorectal cancer and has been shown to be related to lymph node metastasis (22/22, 100%). Tumor budding is assessed in one hotspot (in a field measuring 0.785 mm2) at the invasive front (22/22, 100%). A three-tier system should be used along with the budding count in order to facilitate risk stratification in colorectal cancer (23/23, 100%). Tumor budding and tumor grade are not the same (23/23, 100%). Tumor budding should be included in guidelines/protocols for colorectal cancer reporting (23/23, 100%). Members of the ITBCC were able to reach strong consensus on a single international, evidence-based method for tumor budding assessment and reporting. It is proposed that this method be incorporated into colorectal cancer guidelines/protocols and staging systems.

Systematic review and meta-analysis of the impact of tumour budding in colorectal cancer

Background:

Tumour budding is a histological finding in epithelial cancers indicating an unfavourable phenotype. Previous studies have demonstrated that it is a negative prognostic indicator in colorectal cancer (CRC), and has been proposed as an additional factor to incorporate into staging protocols.

Methods:

A systematic review of papers until March 2016 published on Embase, Medline, PubMed, PubMed Central and Cochrane databases pertaining to tumour budding in CRC was performed. Study end points were the presence of lymph node metastases, recurrence (local and distal) and 5-year cancer-related death.

Results:

A total of 7821 patients from 34 papers were included, with a mean rate of tumour budding of 36.8±16.5%. Pooled analysis suggested that specimens exhibiting tumour budding were significantly associated with lymph node positivity (OR 4.94, 95% CI 3.96–6.17, P<0.00001), more likely to develop disease recurrence over the time period (OR 5.50, 95% CI 3.64–8.29, P<0.00001) and more likely to lead to cancer-related death at 5 years (OR 4.51, 95% CI 2.55–7.99, P<0.00001).

Conclusions:

Tumour budding in CRC is strongly predictive of lymph node metastases, recurrence and cancer-related death at 5 years, and its incorporation into the CRC staging algorithm will contribute to more effective risk stratification.

KRAS, NRAS, BRAF mutations and high counts of poorly differentiated clusters of neoplastic cells in colorectal cancer: observational analysis of 175 cases

A novel grading system based on the counting of poorly differentiated clusters (PDC) of neoplastic cells at the invasive margin and in the tumour stroma was recently introduced among the histological parameters predictive of adverse clinical outcome in colorectal cancer (CRC). The aim of this study was to correlate the histological grade based on PDC and the mutational status of KRAS, NRAS and BRAF genes in 175 consecutive CRCs. The highest PDC count under the objective lens of a ×20 microscopic field in each tumour was considered for grading assessment, so that PDC counts <5, 5-9 and ≥10 PDCs were defined grade 1, grade 2 and grade 3, respectively. Hotspots mutations were identified using the MassArray platform. Overall, there were 42 (24%) mutated tumours. Mutational status was significantly associated with high pT stage (p = 0.0021), advanced pTNM stage (p = 0.0018), nodal metastases (p = 0.006), tumour budding (p = 0.022) and high PDC grade (p = 0.0022). KRAS mutations were significantly associated with PDC grade (p = 0.0379), while BRAF mutations were associated with PDC-G3 although statistical significance was not reached. No significant associations were found between NRAS and PDC. The significant association between mutated KRAS and PDC grade suggests that KRAS mutations may be involved in the formation of PDC.

A novel histologic grading scheme based on poorly differentiated clusters is applicable to treated rectal cancer and is associated with established histopathological prognosticators

The conventional histologic grading of colorectal cancer (CRC) is less suited for resected rectal cancer following neoadjuvant chemoradiation. Enumeration of poorly differentiated clusters (PDC) is a recently proposed histologic grading scheme. We aimed to apply PDC grading to treated rectal cancer and to test the prognostic significance of this novel approach. Archived hematoxylin and eosin slides of 72 rectal adenocarcinomas resected following neoadjuvant treatment were retrieved. PDC, tumor budding, and tumor regression were assessed. The parameters were correlated with clinicopathological features and survival. PDC was strongly associated with tumor budding, perineural invasion (PNI), metastasis, and low degree of tumor regression. Tumor budding was significantly associated with lymphovascular invasion and PNI, and metastasis. Tumors with a lower degree of regression were more likely to show high pathologic T stage and advanced clinical stage. Local recurrence was associated with poor survival. PDC did not correlate with overall survival. PDC grading is applicable to resected rectal cancer status post neoadjuvant treatment and correlates with established histopathological prognosticators. PDC and tumor budding may represent a histologic spectrum reflective of the same biological significance. Validation and incorporation of these simple histologic grading schemes may strengthen the prognostic power of the histologic parameters that influence the oncologic outcome in treated rectal cancer. Further study to evaluate the significance of PDC as an oncologic prognosticator is warranted.

Poorly differentiated clusters (PDC) in colorectal cancer: what is and ought to be known

Background

The counting of poorly differentiated clusters of 5 or more cancer cells lacking a gland-like structure in a tumor mass has recently been identified among the histological features predictive of poor prognosis in colorectal cancer.

Main body

Poorly differentiated clusters can easily be recognized in the histological sections of colorectal cancer routinely stained with haematoxylin and eosin. Despite some limitations related to specimen fragmentation, counting can also be assessed in endoscopic biopsies. Based on the number of poorly differentiated clusters that appear under a microscopic field of a ×20 objective lens (i.e., a microscopic field with a major axis of 1 mm), colorectal cancer can be graded into malignancies as follows: tumors with <5 clusters as grade 1, tumors with 5 to 9 clusters as grade 2, and tumors with ≥10 clusters as grade 3. High poorly differentiated cluster counts are significantly associated with peri-neural and lympho-vascular invasion, the presence of nodal metastases or micrometastases, as well as shorter overall and progression free survival to colorectal cancer.

Conclusion

The morphological aspects and clinical relevance of poorly differentiated clusters counting in colorectal cancer are discussed in this review.

Histologic prognostic markers in stage IIA colorectal cancer: a comparative study

OBJECTIVE

pTNM stage IIA colorectal cancer (CRC) is not currently submitted to any adjuvant treatment due to its good prognosis. Nevertheless, a percentage of cases unexpectedly recur. The aim of this study was to assess and compare the prognostic value and inter-observer agreement of a novel histological grading system based on the counting of poorly differentiated clusters (PDC) of cancer cells and that of conventional histological grade, lymphatic, venous and perineural invasion (LVI, VI, PNI), tumour budding (TB) and tumor border configuration in stage IIA CRC.

MATERIALS AND METHODS

the afore mentioned histological parameters were assessed in 82 stage IIA CRCs. Inter-observer agreement and correlation with tumour relapse were analyzed by using Fleiss-Cohen's weighted K statistics, Fisher exact test and Chi-squared test. The Mantel-Cox log-rank test was applied to assess the strength of association with disease-free interval (DFI).

RESULTS

inter-observer agreement was very good/good in the assessment of PDC presence and grade, while it was moderate at best in the evaluation of the other parameters. The presence of PDC, high PDC grade, LVI and TB were significantly associated with disease progression (p < 0.0001; p = 0.0012; p = 0.0308; p = 0.0002) and shorter DFI (p = 0.0001; p < 0.0001; p = 0.0129; p = 0.0008). PDC presence (p < 0.0001) and TB (p = 0.012) were independent prognostic factors in multivariate analysis.

CONCLUSIONS

our findings suggest that the assessment of PDC may be useful to stratify patients with stage IIA CRC for recurrence risk, and to identify high risk patients who could benefit from adjuvant chemotherapy.

Prognostic significance of grading based on the counting of poorly differentiated clusters in colorectal mucinous adenocarcinoma

Mucinous adenocarcinoma (MAC) of the colon and rectum is a histological entity with still indefinite prognostic significance. Although it was previously designated as poorly differentiated by convention, the most recent World Health Organization guidelines indicate that the level of maturation of the epithelium determines differentiation in MAC and that microsatellite instability status should be taken into account for its histological grading. Nonetheless, precise criteria for grading are not provided, and the prognostic value of histological grading in MAC still remains unclear. In the present study we aimed to investigate the prognostic value of a grading system based on the counting of poorly differentiated clusters (PDC) of neoplastic cells in 108 colorectal MACs and to compare its reproducibility and significance with those of a grading system based on glandular differentiation. We found that PDC grade was more reproducible and significantly associated with disease progression (P = .0089) as well as with death from colorectal cancer (P = .0035) in our MACs, as compared to the grade based on glandular differentiation, which was not associated with any of the clinicopathologic variables. Moreover, PDC grade emerged as a significant, independent prognostic factor of recurrence-free survival (P = .0198) and cancer-specific survival (P = .0293) in MAC. Interestingly, the prognostic value of PDC grade was unaltered following incorporation of mismatch repair system status in grading. In conclusion, we demonstrated for the first time that PDC grading is feasible, reproducible, and prognostically relevant in MAC, which may support its use in routine practice.

Poorly differentiated clusters with larger extents have a greater impact on survival: a semi-quantitative pathological evaluation for 239 patients with non-mucinous pT2-3 colorectal carcinoma

BACKGROUND

Poorly differentiated clusters (PDCs) at the invasive front of tumors in colorectal cancer (CRC) have recently been highlighted as histological prognosticators. We aimed to assess the clinical importance of extent of PDCs in CRC.

METHODS

A total of 239 patients with non-mucinous pT2 and pT3 CRC were pathologically reviewed. PDCs were defined as cancer clusters composed of ≥5 cancer cells lacking full glandular formation. Patients were classified according to the number of PDCs observed under a × 20 objective lens. Patients with <5 clusters were classified as G1, those with 5 to 9 clusters were classified as G2, and those with ≥10 clusters were classified as G3. In addition, in order to semi-quantitatively evaluate the PDCs, the extent of the highest grade of PDCs at the tumor's invasive front was measured and summated, if separately distributed. We identified cutoffs for the extents of PDCs and compared the results with the patients' survival rates.

RESULTS

The number of patients with G1, G2, and G3 clusters was 140, 46, and 53, respectively. The presence of G3 PDCs was significantly correlated with lymphatic permeation (P < 0.0001) and node involvement (P < 0.0001). The 5-year overall survival rates of G1, G2, and G3 were 91%, 88%, and 76%, respectively. Based on the Kaplan-Meier method, 5- and 10-mm cutoffs were identified as the statistically reliable stratification for the extents of G3 clusters, and 15, 20, and 18 G3 patients exhibited extents of <5 mm, 5 to 9 mm, and ≥10 mm, respectively; however, cutoffs for the extents of G1 and G2 clusters were not obtained. In the subgroup analysis, when the extents of G3 clusters were subclassified into <5 mm as G3a, 5 to 9 mm as G3b, and ≥10 mm as G3c, the 5-year overall survival rates were 83%, 62%, and 44%, respectively.

CONCLUSIONS

G3 PDCs were highly indicative of tumor aggressiveness. Quantitative evaluation that takes into account the extent of PDCs would provide more concise prognostic information. Our results suggest that G3 PDCs with a larger extent are closely associated with unfavorable patient outcome.

Clinicopathologic impacts of poorly differentiated cluster-based grading system in colorectal carcinoma

Differentiation-based histologic grading of colorectal carcinoma (CRC) is widely used, but its clinical impact is limited by insufficient prognostic value, interobserver disagreement, and the difficulty of its application to CRC with specific histologic types such as mucinous and medullary carcinoma. A recently proposed novel grading system based on quantifying poorly differentiated clusters (PDCs) claims to have the advantages of reproducibility and improved prognostic value, and might apply to heterogeneous CRC. We aimed to validate the clinicopathologic significance of the PDCs-based grading system and to determine the relationship between this grading system and microsatellite instability (MSI). Two hundred and one patients who had undergone radical surgery were reviewed. Based on the number of PDCs, 85, 58, and 58 tumors were classified as grade (G) 1 (42.3%), G2 (28.9%), and G3 (28.9%), respectively. PDCs-based grade was significantly associated with T, N, and M stages; lymphovascular invasion; conventional histologic grade; and frequent tumor budding (all P <0.001). In multivariate analysis, PDCs-based grade was found to be an independent prognostic factor for disease-free survival (P = 0.022; hazard ratio, 3.709 [G2], 7.461 [G3]). G3 CRC significantly correlated with high MSI (MSI-H) compared to G1 and G2 (P = 0.002; odds ratio, 5.750). In conclusion, this novel grading would provide valuable prognostic information to a greater number of patients and would require continued verification. PDCs-based grading is feasible for CRCs with heterogeneous morphology, and we propose that the association between G3 and MSI-H be further evaluated in different histological subtypes of CRC.