Impact of peritumoral and intratumoral budding in esophageal adenocarcinomas

Prognostic significance of tumour budding in noncolorectal gastrointestinal tract and pancreatobiliary tract: a systematic review and meta-analysis

Tumour budding shows promise as a prognostic factor in various cancers, but its widespread application is hindered by the lack of large, validated studies and standardized criteria. This meta-analysis aims to review and examine the prognostic role of tumour budding specifically in noncolorectal gastrointestinal and pancreatobiliary tract cancers, broadening our perspective on its clinical relevance. The literature review was conducted through PubMed, Embase, and Web of Science from inception till 20 February 2023. Pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were calculated to assess the relation between tumour budding and clinicopathologic features, as well as overall survival. Each study was evaluated using the Newcastle-Ottawa Scale and both heterogeneity and publication bias were analysed. In this meta-analysis of 57 studies across various cancer types, multivariate HR revealed worse overall survival in oesophageal squamous cell carcinoma (HR 3.34 [95% CI 2.21-5.04]), gastric adenocarcinoma (2.03 [1.38-2.99]), pancreatic ductal adenocarcinoma (2.56 [2.02-3.25]), and biliary tract adenocarcinoma (3.11 [2.46-3.93]) with high-grade tumour budding. Additionally, high-grade tumour budding consistently correlated with adverse clinicopathological features, including lymph node metastasis, lymphovascular invasion, and distant metastasis without any observed inverse association. High heterogeneity was noted. Our study suggests that tumour budding is a valuable prognostic marker in various cancers. Nonetheless, standardized criteria tailored to specific organ types are necessary to enhance its clinical utility.

Tumor budding to investigate local invasion, metastasis, and prognosis of head and neck carcinoma: A systematic review

The aim of this systematic review is to shed light on the role of tumor budding (TB) in the biology, behavior, and prognosis of head and neck squamous cell carcinoma (HNSCC). A search was run in PubMed, Scopus, and Embase databases following PRISMA guidelines. After full-text screening and application of inclusion/exclusion criteria, 36 articles were included. Several investigations support the prognostic role of TB, which might play a role in selecting rational treatment strategies. To achieve this goal, further research is needed for greater standardization in TB quantification. Although TB is not included as a negative prognostic factor in the current management guidelines, it might be reasonable to consider a closer follow-up for HNSCC cases with high histopathological evidence of TB.

Comparison between Peritumoral and Intratumoral Budding in Colorectal Cancer

Tumor budding (TB) is classified, based on location, into peritumoral budding (PTB) or intratumoral budding (ITB). This study aimed to evaluate the relationship between PTB and ITB in colorectal cancers (CRCs). PTB and ITB were investigated and subsequently divided into high and low groups. CRCs were divided into three groups: (1) high PTB/ITB, (2) high PTB or ITB, and (3) low PTB/ITB. The clinicopathological and prognostic significances were evaluated according to the three tumor budding (TB) groups. High PTB/ITB and low PTB/ITB were identified in 32 (12.0%) and 135 (50.8%) patients, respectively. A total of 99 patients (37.2%) were found to have high PTB or ITB. TB was significantly correlated with lymphatic and perineural invasion, lymph node metastasis, metastatic lymph node ratio, distant metastasis, and a higher pTNM stage. A significant correlation was found between high PTB and high ITB (p = 0.010). The amount of PTB was found to increase significantly with the amount of ITB (p < 0.001) in a linear regression test. Patients with high PTB/ITB had worse overall and recurrence-free survival than those with high PTB or ITB. Conversely, patients with low PTB/ITB had better overall and recurrence-free survival rates than those with high PTB or ITB. However, there was no significant difference in overall and recurrence-free survival between patients with high PTB/low ITB and high ITB/low PTB (p = 0.336 and p = 0.623, respectively). In summary, the presence of TB, regardless of PTB or ITB, was significantly correlated with aggressive tumor behavior and a worse prognosis than the absence of TB. Additionally, the present study demonstrated that it is feasible to stratify the prognosis of patients based on whether they have both PTB and ITB or only one of the two.

Diagnosis and management of Barrett esophagus: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

MR1 : ESGE recommends the following standards for Barrett esophagus (BE) surveillance:- a minimum of 1-minute inspection time per cm of BE length during a surveillance endoscopy- photodocumentation of landmarks, the BE segment including one picture per cm of BE length, and the esophagogastric junction in retroflexed position, and any visible lesions- use of the Prague and (for visible lesions) Paris classification- collection of biopsies from all visible abnormalities (if present), followed by random four-quadrant biopsies for every 2-cm BE length.Strong recommendation, weak quality of evidence. MR2:  ESGE suggests varying surveillance intervals for different BE lengths. For BE with a maximum extent of ≥ 1 cm and < 3 cm, BE surveillance should be repeated every 5 years. For BE with a maximum extent of ≥ 3 cm and < 10 cm, the interval for endoscopic surveillance should be 3 years. Patients with BE with a maximum extent of ≥ 10 cm should be referred to a BE expert center for surveillance endoscopies. For patients with an irregular Z-line/columnar-lined esophagus of < 1 cm, no routine biopsies or endoscopic surveillance are advised.Weak recommendation, low quality of evidence. MR3:  ESGE suggests that, if a patient has reached 75 years of age at the time of the last surveillance endoscopy and/or the patient's life expectancy is less than 5 years, the discontinuation of further surveillance endoscopies can be considered. Weak recommendation, very low quality of evidence. MR4:  ESGE recommends offering endoscopic eradication therapy using ablation to patients with BE and low grade dysplasia (LGD) on at least two separate endoscopies, both confirmed by a second experienced pathologist.Strong recommendation, high level of evidence. MR5:  ESGE recommends endoscopic ablation treatment for BE with confirmed high grade dysplasia (HGD) without visible lesions, to prevent progression to invasive cancer.Strong recommendation, high level of evidence. MR6:  ESGE recommends offering complete eradication of all remaining Barrett epithelium by ablation after endoscopic resection of visible abnormalities containing any degree of dysplasia or esophageal adenocarcinoma (EAC).Strong recommendation, moderate quality of evidence. MR7:  ESGE recommends endoscopic resection as curative treatment for T1a Barrett's cancer with well/moderate differentiation and no signs of lymphovascular invasion.Strong recommendation, high level of evidence. MR8:  ESGE suggests that low risk submucosal (T1b) EAC (i. e. submucosal invasion depth ≤ 500 µm AND no [lympho]vascular invasion AND no poor tumor differentiation) can be treated by endoscopic resection, provided that adequate follow-up with gastroscopy, endoscopic ultrasound (EUS), and computed tomography (CT)/positrion emission tomography-computed tomography (PET-CT) is performed in expert centers.Weak recommendation, low quality of evidence. MR9:  ESGE suggests that submucosal (T1b) esophageal adenocarcinoma with deep submucosal invasion (tumor invasion > 500 µm into the submucosa), and/or (lympho)vascular invasion, and/or a poor tumor differentiation should be considered high risk. Complete staging and consideration of additional treatments (chemotherapy and/or radiotherapy and/or surgery) or strict endoscopic follow-up should be undertaken on an individual basis in a multidisciplinary discussion.Strong recommendation, low quality of evidence. MR10 A: ESGE recommends that the first endoscopic follow-up after successful endoscopic eradication therapy (EET) of BE is performed in an expert center.Strong recommendation, very low quality of evidence. B:  ESGE recommends careful inspection of the neo-squamocolumnar junction and neo-squamous epithelium with high definition white-light endoscopy and virtual chromoendoscopy during post-EET surveillance, to detect recurrent dysplasia.Strong recommendation, very low level of evidence. C:  ESGE recommends against routine four-quadrant biopsies of neo-squamous epithelium after successful EET of BE.Strong recommendation, low level of evidence. D:  ESGE suggests, after successful EET, obtaining four-quadrant random biopsies just distal to a normal-appearing neo-squamocolumnar junction to detect dysplasia in the absence of visible lesions.Weak recommendation, low level of evidence. E:  ESGE recommends targeted biopsies are obtained where there is a suspicion of recurrent BE in the tubular esophagus, or where there are visible lesions suspicious for dysplasia.Strong recommendation, very low level of evidence. MR11:  After successful EET, ESGE recommends the following surveillance intervals:- For patients with a baseline diagnosis of HGD or EAC:at 1, 2, 3, 4, 5, 7, and 10 years after last treatment, after which surveillance may be stopped.- For patients with a baseline diagnosis of LGD:at 1, 3, and 5 years after last treatment, after which surveillance may be stopped.Strong recommendation, low quality of evidence.

Tumor budding in gastric cancer

The tumor, nodes, metastasis (TNM) staging system has long been the gold standard for the classification and prognosis of solid tumors. However, the TNM staging system is not without limitations. Prognostic heterogeneity exists within patients at the same stage. Therefore, the pursuit of other biomarkers with the potential to classify patients with cancer has never stopped. One of them, tumor budding (TB), has gained much success in colorectal cancer. In recent years, TB in gastric cancer has attracted much attention from researchers, beginning to reveal the molecular and biological aspects of this phenomenon in gastric cancer, and has emerged as a promising prognostic biomarker in gastric cancer, predicting disease progression and unfavorable survival. Therefore, it is time and essential to provide a holistic overview of TB in gastric cancer, which has not been achieved and is the aim of this review.

Is there no need to discuss adjuvant chemotherapy in stage II colon cancer patients with high tumor budding and lymphovascular invasion?

PURPOSE

The aim of this study is to evaluate the clinicopathologic associations of tumor budding (Bd) as well as other potential prognosticators including lymphovascular invasion (LVI) in T3/4aN0 colon cancer patients and to investigate their impact on the outcome.

METHODS

The patients were enrolled in three groups according to the number of budding as Bd1 (0-4 buds), Bd2 (5-9 buds), and Bd3 (> 10 buds). These groups were retrospectively compared in terms of demographic features, other tumor characteristics, operative outcomes, recurrences, and survival. The mean follow-up time was 58 ± 22 months.

RESULTS

A total of 194 patients were divided as follows: 97 in Bd1, 41 in Bd2, and 56 in Bd3 groups. The Bd3 group was associated with significantly higher LVI and larger tumor size. The rate of recurrence increased progressively from 5.2% in Bd1 to 9.8% in Bd2 and to 17.9% in Bd3 group (p = 0.03). More importantly, the 5-year overall survival (OS: Bd1 = 92.3% vs. Bd2 = 88% vs. Bd3 = 69.5%, p = 0.03) and disease-free survival (DFS: Bd1 = 87.9% vs. Bd2 = 75.3% vs. Bd3 = 66%, p = 0.02) were significantly worse in Bd3 group. In addition, in the subgroup of patients with the presence of Bd3 and LVI together, the 5-year OS (60% vs. 92%, p = 0.001) and DFS (56.1% vs. 85.4%, p = 0.001) were significantly worse. In multivariate analysis, Bd3+LVI was significantly associated with poor OS and DFS (p < 0.001).

CONCLUSION

In patients with T3/4aN0 colon cancer, high tumor budding negatively affects long-term oncological outcomes. These findings strongly suggest that adjuvant chemotherapy be considered for the patients with Bd3 and LVI together.

Surgical pathology of adenocarcinomas arising around or within the gastroesophageal junction

Classification of adenocarcinomas (AC) arising around or within the gastroesophageal junction (GEJ) is hampered by major morphologic and phenotypic overlaps. We reviewed the surgical pathology of esophagectomy specimens of 115 primary resected AC of the esophagus as defined by the 5th edition of the WHO classification regarding the anatomical site of the tumor, with corresponding categorization according to the Siewert AEG Classification and the preceding 4th edition of the WHO (discriminating esophageal adenocarcinomas/EAC and adenocarcinomas of the gastroesophageal junction/AdGEJ), and further histology findings. In addition, immunohistochemistry (IHC) for CDX2, CK7, CK20, MUC2, MUC5AC and MUC6 was performed. Sixty-eight cases were Siewert AEG type I and 47 cases Siewert AEG type II. Out of the AEG I tumors, 26 were classified as AdGEJ. Regardless of the classification system, more proximally located tumors showed less aggressive behavior with lower rates of lymph node metastases, lymphatic, venous and perineural invasion, better histological differentiation (p < 0.05 each) and were more frequently associated with pre-neoplastic Barrett's mucosa (p < 0.001). Histologically, the tumors displayed intestinal morphology in the majority of cases. IHC showed non-conclusive patterns with a frequent CK7+/CK20+ immunophenotype in all tumors, but also a gastric MUC5AC+ and MUC6+ phenotype in some proximal tumors. In conclusion, histology of the tumors and IHC failed to distinguish reliably between more proximal and more distal tumors. The presence of Barrett's mucosa rather than location alone, however, may help to further differentiating adenocarcinomas arising in this region and may be indicative for a particular biologic type.

Tumor Budding Assessment with Cytokeratin and Its Significance in Laryngeal Squamous Cell Carcinomas

There is a need for novel prognostic parameters in assessing laryngeal squamous cell carcinoma (LSCC). Tumor budding is an instrumental parameter, which has hardly been studied before in this organ. This study aimed to assess tumor budding in LSCCs with routine hematoxylin and eosin (H&E) stain as well as cytokeratin (CK) immunohistochemistry (IHC). Objectives were to compare the effectiveness of both these methods to assess tumor budding, to investigate the association of tumor budding and clinicopathologic features, and to determine the prognostic significance of tumor budding in LSCCs. Fifty laryngectomy specimens were included. Tumor budding was counted (20x) on slides stained with IHC-CK, and highest count per slide was noted. The cases were classified as positive (> 1 buds) or negative (no buds present). The budding index was categorized as low (< 5 buds) or high (> 5 buds). Tumor budding on H&E was absent, low and high grade in 28%, 30% and 42% cases respectively, when compared to CK-IHC in 17%, 24% and 59% of cases, respectively. Presence of lymphoplasmacytic infiltration significantly correlated with tumor budding and higher grade. Transglottic location of tumor and pT stage was associated with high budding. Presence of lymphoplasmacytic infiltrate significantly correlated with worse prognosis. Tumor budding, an easily assessable, inexpensive histopathologic parameter has seldom been studied in LSCCs. Presence of lymphoplasmacytic infiltrate in routine preoperative biopsy reporting could be useful in prognostication. CK-IHC is helpful to detect especially cases with low-grade tumor budding.

Perineural Invasion Is a Significant Indicator of High Malignant Degree and Poor Prognosis in Esophageal Cancer: A Systematic Review and Meta-Analysis

Background

Perineural invasion (PNI) is a malignant metastatic mode of tumors and has been reported in many tumors including esophageal cancer (EC). However, the role of PNI in EC has been reported differently. This systematic review and meta-analysis aims to focus on the role of PNI in EC.

Methods

Eight databases of CNKI, VIP, Wanfang, Scopus, Wiley, ISI, PubMed, and EBSCO are used for literature search. The association of PNI with gender, pathological stages of T and N (pT and pN), lymphovascular invasion (LVI), lymph node metastasis, 5-year overall survival (OS), and 5-year disease-free survival (DFS) was examined in the meta-analysis by Revman5.0 Software. The pooled OR/HR and 95% CI were used to assess the risk and prognostic value.

Results

Sixty-nine published studies were screened for analysis of PNI in EC. The incidence of PNI in esophageal squamous carcinoma (ESCC) and esophageal adenocarcinoma (EAC) was different, but not statistically significant (p > 0.05). The PNI-positive patients had a significantly higher risk of pT stage (OR = 3.85, 95% CI = 2.45–6.05, p < 0.00001), pN stage (OR = 1.86, 95% CI = 1.52–2.28, p < 0.00001), LVI (OR = 2.44, 95% CI = 1.55–3.85, p = 0.0001), and lymph node metastasis (OR = 2.87, 95% CI = 1.56–5.29, p = 0.0007). Furthermore, the cumulative analysis revealed a significant correlation between PNI and poor OS (HR = 1.37, 95% CI = 1.24–1.51, p < 0.0001), as well as poor DFS (HR = 1.55, 95% CI = 1.38–1.74, p < 0.0001).

Conclusion

PNI occurrence is significantly related to tumor stage, LVI, lymph node metastasis, OS, and DFS. These results indicate that PNI can serve as an indicator of high malignant degree and poor prognosis in EC.

Post-neoadjuvant assessment of tumour budding according to ITBCC subgroups delivers stage- and regression-grade independent prognostic information in intestinal-type gastric adenocarcinoma

Tumour budding (TB) has been associated with adverse clinicopathological factors and poor survival in a plethora of therapy‐naïve carcinoma entities including gastric adenocarcinoma (GC). As conventional histopathological grading is usually omitted in the post‐neoadjuvant setting of GC, our study aimed to investigate the prognostic impact of TB in GCs resected after neoadjuvant therapy. We evaluated TB according to the criteria from the International Tumour Budding Consensus Conference (ITBCC) in 167 post‐neoadjuvant resections of intestinal‐type GC and correlated the results with overall survival (OS) and clinicopathological parameters. GCs were categorised into Bd1 (0–4 buds, low TB), Bd2 (5–9 buds, intermediate TB), and Bd3 (≥10 buds, high TB). Carcinomas with intermediate and high TB were significantly enriched in higher ypTNM stages and strongly associated with reduced 5‐year OS in univariable analyses (p < 0.001). In multivariable analyses including sex, age, resection status, UICC stage, and tumour regression grading, TB remained a stage‐independent predictor of survival (p < 0.001, hazard ratio Bd2: 2.60, Bd3: 4.74). The assessment of TB according to the ITBCC criteria provides valuable prognostic information in the post‐neoadjuvant setting of intestinal‐type GC and may be a considerable substitute for the conventional grading system in GCs after neoadjuvant therapy.

Prognostic significance of tumor budding thresholds in oral tongue squamous cell carcinoma

Oral tongue squamous cell carcinoma (OTSCC) represents the most common malignancy of the oral cavity. Tumor budding (TB) is a reliable prognostic factor in OTSCC; however, a standardized scoring system is not still validated. The study aims to evaluate the prognostic role of TB in 211 OTSCC patients treated between 1997-2018. TB was evaluated on haematoxylin and eosin-stained sections in the hotspot area of the infiltrative front (×200-magnification). It was scored using a two-tier, a three-tier system, and according to BD-model and revised-Grading system. Univariate and multivariate Cox regression analyses of disease-specific survival (DSS) and disease-free survival (DFS) were performed. A p-values<0.05 was considered as statistically significant. The two-tier and three-tier system resulted an independent prognostic factor of DSS. High-risk patients had a 2.21 and 3.08 times-increased probability of poor DSS compared to low-risk group. It is significantly increased even for intermediate-risk group. No significant differences emerged classifying patients according to BD-model and revised-Grading. These data confirm the prognostic value of TB in predicting DSS in OTSCC. Classifying patients in two groups using the 5-buds cut-off significantly discriminates their outcomes. Since the established role of DOI and the poor prognostic value of grading, TB could be considered an independent prognostic marker.

Clinicopathologic correlations of superficial esophageal adenocarcinoma in endoscopic submucosal dissection specimens

Background

Endoscopic submucosal dissection (ESD) is a novel endoscopic treatment for early esophageal adenocarcinoma (EAC). The western pathologists’ experience with ESD specimens remains limited. This study aimed to correlate histopathologic features of Barrett’s esophagus (BE)-associated adenocarcinoma in ESD resections with clinical outcomes to determine whether they aid future management decisions.

Methods

We retrospectively evaluated 49 consecutive ESD resection specimens from 42 patients with BE-associated adenocarcinoma (24 intramucosal and 18 submucosal EAC) at a single tertiary referral center. Pathologic evaluation included presence of dysplasia, invasive adenocarcinoma, peritumoral inflammation, desmoplasia, lymphovascular and perineural invasion; tumor differentiation, depth of invasion, morphology, and budding; and margin status for dysplasia or carcinoma. Follow up data included endoscopic biopsies in 35 patients and pathology reports of esophagectomies in 11 patients. Poor outcomes were defined as recurrence or residual invasive adenocarcinoma at esophagectomy, metastasis on imaging, or R1 resection in patients undergoing ESD for tumor debulking.

Results

Two patients (8%) with intramucosal adenocarcinoma and 9 patients (50%) with submucosal adenocarcinoma had poor outcomes. Histopathologic features associated with poor outcomes included poor differentiation, lymphovascular invasion, submucosal invasion > 500 μm, tumor budding, and tubuloinfiltrative histologic pattern. Four patients had positive deep margin away from the deepest tumor invasion and did not show residual tumor on follow up.

Conclusions

Our results validated European Society of Gastroenterology (ESGE) guidelines of high-risk pathologic features for additional therapy in esophageal adenocarcinoma and identified tumor budding frequently in association with other high-risk features. Positive deep margin distant from deepest tumor invasion could be procedural and warrants endoscopic correlation for management.

Prognostic features of the tumour microenvironment in oesophageal adenocarcinoma

Oesophageal adenocarcinoma (OAC) is a disease with an incredibly poor survival rate and a complex makeup. The growth and spread of OAC tumours are profoundly influenced by their surrounding microenvironment and the properties of the tumour itself. Constant crosstalk between the tumour and its microenvironment is key to the survival of the tumour and ultimately the death of the patient. The tumour microenvironment (TME) is composed of a complex milieu of cell types including cancer associated fibroblasts (CAFs) which make up the tumour stroma, endothelial cells which line blood and lymphatic vessels and infiltrating immune cell populations. These various cell types and the tumour constantly communicate through environmental cues including fluctuations in pH, hypoxia and the release of mitogens such as cytokines, chemokines and growth factors, many of which help promote malignant progression. Eventually clusters of tumour cells such as tumour buds break away and spread through the lymphatic system to nearby lymph nodes or enter the circulation forming secondary metastasis. Collectively, these factors need to be considered when assessing and treating patients clinically. This review aims to summarise the ways in which these various factors are currently assessed and how they relate to patient treatment and outcome at an individual level.

Intratumoural Budding is Associated with Poor Clinical Outcome in Early-Stage Clear Cell Carcinoma of Ovary

AIMS

Clear cell carcinoma of ovary (CCC) is considered a high-grade malignancy by default and the role of histological grading for assessing clinical outcome is not established. We aimed to evaluate histopathological features associated with clinical outcome in CCC patients. Seventy-six cases of CCC with available clinical follow-up information were studied. Histopathological features including tumour size, architectural patterns, nuclear atypia, mitotic activity, intraumoural and peritumoral inflammation, presence of endometriosis, peritumoural and intratumoural budding were evaluated. Multivariate analysis was performed with logistic regression and Kaplan-Meier survival curves with log rank test were used for survival analysis.

METHODS AND RESULTS

Forty cases (53%) presented at stage I. Complete response to treatment was achieved in 65%, while 35% of patients had tumor recurrence or progression of disease despite treatment. At last follow-up, 13% had died of disease, 20% were alive with disease and 67% had no evidence of disease. Higher stage (p=0.0016) and presence of intratumoural budding (p=0.0454) were independently associated with recurrence/disease progression. Advanced stage (p=0.0011), presence of lymph node involvement (p=0.0003), intratumoural budding (p=0.0023) and peritumoural budding (p=0.0334) were significantly associated with shorter survival. Intratumoural budding was significantly associated with recurrent/progressive disease (p=0.0195) and shorter survival (p=0.0277) within the cohort of low-stage (I/II) patients as well.

CONCLUSIONS

We have shown that besides the classic prognostic factors of stage and lymph node status, presence of tumour budding is associated with poorer outcome in patients with CCC. Specifically, evaluation of intratumoural budding may help to better predict prognosis in patients with early-stage disease.

Prognostic impact of tumor budding in endometrial carcinoma within distinct molecular subgroups

Tumor budding is a robust prognostic parameter in several tumor entities but is rarely investigated in endometrial carcinoma. We applied the recently standardized counting method from the International Tumor Budding Consensus Conference for colorectal cancer (ITBCC) on a cohort of 255 endometrial carcinomas with known molecular profiles according to The Cancer Genome Atlas (TCGA) subgroups. Our investigation aims to clarify the potential prognostic role of tumor budding in endometrial carcinoma in contrast to other known prognostic factors, including molecular factors. In addition, the microcystic elongated and fragmented (MELF) pattern and tumor budding were compared with respect to their potential as markers for epithelial-mesenchymal transition (EMT). Tumor budding was found in n = 67 (26.3%) tumors, with a very low mean of 0.7 buds per ×20 HE field. Tumor budding was significantly associated with depth of invasion, nodal status, lymphatic invasion (each p < 0.001), grading (p = 0.004), and vascular invasion (p = 0.01). Tumor budding showed moderate inter-observer-variability with prognostic stratification irrespective of the observer (κ-value = 0.448). In multivariate analysis, tumor budding served as a significant independent prognosticator for worse outcomes in overall and recurrence-free survival (HR 2.376 and 2.736, p < 0.001), but not when the TCGA subgroups entered into the analysis. In consequence, dependency had to be clarified in the subgroup analysis for Polymerase E mutated (POLEmut), mismatch repair deficient (MMRdef), nonspecific mutation profile (NSMP), and P53 aberrant (P53abn) endometrial carcinomas. A particular impact was identified in the intermediate prognostic groups of NSMP and MMRdef carcinomas. Tumor budding outperformed the MELF pattern in single and combined prognostic information. In conclusion, the presence of tumor budding alone is a promising, robust, and easy-to-apply prognostic parameter in endometrial carcinoma. In a morpho-molecular approach, it exerts its prognostic potential in the most clinically relevant subgroups of endometrial carcinoma and serves as a good biomarker for EMT.

Tumour budding in solid cancers

Tumour budding is an emerging prognostic biomarker in colorectal cancer (CRC) and other solid cancers. Tumour buds are usually defined as isolated single cancer cells or clusters of up to four cancer cells located at the invasive tumour front. The prognostic value of tumour budding is now supported by a large body of evidence, whereas the utility of this phenotype as a predictive biomarker remains under investigation. The application of tumour budding indices in clinical practice requires a standardized scoring system that can be tailored to specific tumour types and clinical scenarios. In the context of CRC, tumour budding can be assessed according to the method agreed at the International Tumour Budding Consensus Conference (ITBCC) in 2016. Using the ITBCC scoring system, tumour budding is an independent predictor of lymph node metastasis in patients with pT1 CRC and of unfavourable survival in patients with stage II colon cancer. Regardless of the clinical scenario or tumour type, the assertion that 'the more tumour buds, the worse the clinical outcome' applies. In this Review, we provide an overview of tumour budding in solid cancers, highlighting the molecular and biological aspects of this phenomenon, including its associations with epithelial-mesenchymal transition and features of the tumour microenvironment. We also describe the available evidence demonstrating the value of tumour budding as a biomarker across various solid cancers.

Tumor Budding and Poorly Differentiated Clusters in Small Intestinal Adenocarcinoma

The clinicopathologic and prognostic significances of tumor budding (TB) and poorly-differentiated clusters (PDC) have not been investigated in small intestinal adenocarcinomas (SIACs). In 236 surgically-resected SIACs, we counted TB (single cells or clusters ≤4 tumor cells) and PDC (clusters ≥5 tumor cells) at the peritumoral-invasive front (p) and in the intratumoral area (i) independently to classify as grade-1 (≤4), grade-2 (5–9), or grade-3 (≥10). Consequently, grades-2 and -3 were considered high-grade. High-pTB, -iTB, -pPDC, and -iPDC were observed in 174 (73.7%), 129 (54.7%), 118 (50.0%), and 85 (36.0%) cases, respectively. High-TB/PDCs were more frequently observed in tumors with high-grade, higher T- and N-categories and stage grouping, and perineural or lymphovascular invasion. Patients with high-TB/PDC had a shorter survival than those with low-TB/PDC. In a multivariate analysis, high-pTB, nonintestinal type, high N-category, retroperitoneal seeding, and microsatellite-stable were worse independent-prognostic predictors. Subgroup analysis demonstrated that patients with high-pTB showed worse survival (median: 42.5 months) than those with low-pTB (133.7 months; p = 0.007) in the lower stage (stages I–II) group. High-TB/PDC, both in peritumoral and intratumoral localizations, were associated with aggressive behaviors in SIACs. High-pTB can be used as an adverse prognostic indicator in SIAC patients, especially when patients are in early disease stages.

Tumour budding and its clinical implications in gastrointestinal cancers

Tumour budding in colorectal cancer has become an important prognostic factor. Represented by single cells or small tumour cell clusters at the invasion front of the tumour mass, these tumour buds seem to reflect cells in a ‘hybrid’ state of epithelial–mesenchymal transition, and evidence indicates that the presence of these entities is associated with lymph node metastasis, local recurrence and distant metastatic disease. The International Tumour Budding Consensus Conference (ITBCC) has highlighted a scoring system for the reporting of tumour budding in colorectal cancer, as well as different clinical scenarios that could affect patient management. Other organs are not spared: tumour budding has been described in numerous gastrointestinal and non-gastrointestinal cancers. Here, we give an update on ITBCC validation studies in the context of colorectal cancer and the clinical implications of tumour budding throughout the upper gastrointestinal and pancreatico-biliary tract.

Prognostic significance of peritumoural and intratumoural budding in intestinal-type gastric adenocarcinoma

BACKGROUND AND STUDY AIMS

Tumour budding (TB) at the invasive front, termed peritumoural budding (PTB), is an established prognostic factor for many solid tumours. However, intratumoural budding (ITB) in gastric adenocarcinoma (GAC), which is frequently observed at the tumour centre, particularly in tumour biopsy tissues, remains poorly understood. Hence, we aimed to determine the correlation of ITB with PTB and their connection with clinicopathological characteristics as well as their prognostic value in GAC.

PATIENTS AND METHODS

We investigated a total of 153 cases of GAC wherein tissues were primarily resected and their related clinicopathological data. A continuous series of paraffin-embedded tissues was stained by haematoxylin-eosin staining, and budding cells were identified by immunohistochemical staining. PTB and ITB were counted in five fields with the highest density of tumour buds. The selected area was examined under 40 high-power field. Cases were divided into low-grade TB and high-grade TB groups according to the median bud count.

RESULTS

Among the 153 patients with GAC, 51 underwent simultaneous observation of ITB and PTB, which were found to have a significant positive correlation. A higher grade of ITB in tumours was associated with positive lymph node metastasis and could predict a worse prognosis. Additionally, patients with simultaneous PTB and ITB had a shorter overall survival than those with PTB alone, suggesting a worse prognosis.

CONCLUSION

PTB and ITB were found to be adverse prognostic factors and high-risk indicators of intestinal-type GAC, and ITB plays an important role in evaluating GAC prognosis in gastroscopic biopsy tissues. Additionally, TB might become a useful index for predicting GAC prognosis in the future.

Automated tumour budding quantification by machine learning augments TNM staging in muscle-invasive bladder cancer prognosis

Tumour budding has been described as an independent prognostic feature in several tumour types. We report for the first time the relationship between tumour budding and survival evaluated in patients with muscle invasive bladder cancer. A machine learning-based methodology was applied to accurately quantify tumour buds across immunofluorescence labelled whole slide images from 100 muscle invasive bladder cancer patients. Furthermore, tumour budding was found to be correlated to TNM (p = 0.00089) and pT (p = 0.0078) staging. A novel classification and regression tree model was constructed to stratify all stage II, III, and IV patients into three new staging criteria based on disease specific survival. For the stratification of non-metastatic patients into high or low risk of disease specific death, our decision tree model reported that tumour budding was the most significant feature (HR = 2.59, p = 0.0091), and no clinical feature was utilised to categorise these patients. Our findings demonstrate that tumour budding, quantified using automated image analysis provides prognostic value for muscle invasive bladder cancer patients and a better model fit than TNM staging.

Does evaluation of tumour budding in diagnostic biopsies have a clinical relevance? A systematic review

Tumour budding has emerged as a promising prognostic marker in many cancers. We systematically reviewed all studies that evaluated tumour budding in diagnostic biopsies. We conducted a systematic review of PubMed, MEDLINE, Scopus, Web of Science and Cochrane library for all articles that have assessed tumour budding in diagnostic (i.e. pretreatment or pre-operative) biopsies of any tumour type. Two independent researchers screened the retrieved studies, removed duplicates, excluded irrelevant studies and extracted data from the eligible studies. A total of 13 reports comprising 11 cohorts were found to have studied tumour budding in diagnostic biopsies. All these reports showed that evaluation of tumour budding in diagnostic biopsies was easily applicable. A strong association was observed between tumour budding score in diagnostic biopsies and corresponding surgical samples. Evaluation of tumour budding in diagnostic biopsies had a significant prognostic value for lymph node metastasis and patient survival. In all studies, tumour budding was a valuable marker of tumour aggressiveness and can be evaluated in technically satisfactory diagnostic biopsies. Thus, the assessment of tumour budding seems to identify the behaviour of cancer, and therefore to facilitate treatment planning.

Histopathology of Barrett’s Esophagus and Early-Stage Esophageal Adenocarcinoma: An Updated Review

Esophageal adenocarcinoma carries a very poor prognosis. For this reason, it is critical to have cost-effective surveillance and prevention strategies and early and accurate diagnosis, as well as evidence-based treatment guidelines. Barrett’s esophagus is the most important precursor lesion for esophageal adenocarcinoma, which follows a defined metaplasia–dysplasia–carcinoma sequence. Accurate recognition of dysplasia in Barrett’s esophagus is crucial due to its pivotal prognostic value. For early-stage esophageal adenocarcinoma, depth of submucosal invasion is a key prognostic factor. Our systematic review of all published data demonstrates a “rule of doubling” for the frequency of lymph node metastases: tumor invasion into each progressively deeper third of submucosal layer corresponds with a twofold increase in the risk of nodal metastases (9.9% in the superficial third of submucosa (sm1) group, 22.0% in the middle third of submucosa (sm2) group, and 40.7% in deep third of submucosa (sm3) group). Other important risk factors include lymphovascular invasion, tumor differentiation, and the recently reported tumor budding. In this review, we provide a concise update on the histopathological features, ancillary studies, molecular signatures, and surveillance/management guidelines along the natural history from Barrett’s esophagus to early stage invasive adenocarcinoma for practicing pathologists.

Tumor budding as a standardized parameter in gastrointestinal carcinomas: more than just the colon

Tumor budding, defined as single cells or clusters of less than five cells, is thought to be a histomorphologic marker of an aggressive tumor behavior mimicking the embryologic epithelial-mesenchymal transition, and has been well established in the past two decades as a poor prognostic factor in colorectal carcinoma. Slow uptake in routine reporting of this important pathologic prognostic feature was in part due to differing methods of assessment of budding reported in the literature, but has recently been clarified at a consensus conference on tumor budding in colorectal carcinoma. Tumor budding is also increasingly being reported as a useful pathologic prognostic feature in other gastrointestinal carcinomas, including esophageal squamous cell carcinoma and adenocarcinoma, gastric intestinal-type adenocarcinoma, pancreatic ductal adenocarcinoma, and ampullary adenocarcinoma. In this review, we will summarize the studies on tumor budding in gastrointestinal carcinomas, with a focus on the methods of assessment used and the potential clinical applications of the findings.

Immunophenotypic profile of tumor buds in breast cancer

BACKGROUND

Tumor buds are associated with lympho-vascular invasion and lymph node metastases leading to the assumption that they are involved in the early metastatic process. Hence, it would be important to know if tumor buds can be targeted with the most widely used targeted therapies in breast cancer (BC) and if changes in hormone and Her2 status occur. The aim of this study was to answer these questions by determining whether hormone receptor (HR) and Her2 status are expressed in the tumor buds of a large cohort of BCs.

DESIGN

We constructed a tumor bud next-generation tissue microarray (ngTMA) consisting of n = 199 BCs of non-special type. Generally, two 1 mm punches were taken from the tumor bud areas in the periphery (PTB) and within the tumor center (ITB). HR and Her2 status was assessed using immunohistochemistry and fluorescence in situ hybridization, respectively. HR status was positive if ≥1% of tumor bud cells were positive. Her2 status was considered positive if bud cells showed strong complete membranous Her2 over-expression or Her2 amplification.

RESULTS

Most tumor buds were positive for estrogen (ER) (PTB: 86%; ITB: 88.3) and progesterone receptor (PgR) (PTB: 72%; ITB: 72.8%) and Her2 was positive in: PTB 11.5% and ITB 11%. A difference between the main tumor mass and tumor buds (PTB and ITB) was seen for PgR in 3.5% of cases (n = 7). No differences were seen for ER and Her2 between tumor buds and main tumor mass.

CONCLUSION

Most tumor buds (96.5%) share the same HR and Her2 expression profile of the main tumor mass, implying that tumor buds relay on the same pathways as the main tumor mass and might be equally responsive to targeted therapies.

Cytokeratin-based assessment of tumour budding in colorectal cancer: analysis in stage II patients and prospective diagnostic experience

Tumour budding in colorectal cancer is an important prognostic factor. A recent consensus conference elaborated recommendations and key issues for future studies, among those the use of pan‐cytokeratin stains, especially in stage II patients. We report the first prospective diagnostic experience using pan‐cytokeratin for tumour budding assessment. Moreover, we evaluate tumour budding using pan‐cytokeratin stains and disease‐free survival (DFS) in stage II patients. To this end, tumour budding on pan‐cytokeratin‐stained sections was evaluated by counting the number of tumour buds in 10 high‐power fields (0.238 mm²), then categorizing counts as low/high‐grade at a cut‐off of 10 buds, in two cohorts. Cohort 1: prospective setting with 236 unselected primary resected colorectal cancers analysed by 17 pathologists during diagnostic routine. Cohort 2: retrospective cohort of 150 stage II patients with information on DFS. In prospective analysis of cohort 1, tumour budding counts correlated with advanced pT, lymph node metastasis, lymphovascular invasion, perineural invasion (all p < 0.0001), and distant metastasis (p = 0.0128). In cohort 2, tumour budding was an independent predictor of worse DFS using counts [p = 0.037, HR (95% CI): 1.007 (1.0–1.014)] and the low‐grade/high‐grade scoring approach [p = 0.02; HR (95% CI): 3.04 (1.2–7.77), 90.7 versus 73%, respectively]. In conclusion, tumour budding assessed on pan‐cytokeratin slides is feasible in a large pathology institute and leads to expected associations with clinicopathological features. Additionally, it is an independent predictor of poor prognosis in stage II patients and should be considered for risk stratification in future clinical studies.

Tumor Budding: The Name is EMT. Partial EMT

Tumor budding is a histological phenomenon encountered in various cancers, whereby individual malignant cells and/or small clusters of malignant cells are seen in the tumor stroma. Postulated to be mirror epithelial-mesenchymal transition, tumor budding has been associated with poor cancer outcomes. However, the vast heterogeneity in its exact definition, methodology of assessment, and patient stratification need to be resolved before it can be routinely used as a standardized prognostic feature. Here, we discuss the heterogeneity in defining and assessing tumor budding, its clinical significance across multiple cancer types, and its prospective implementation in clinical practice. Next, we review the emerging evidence about partial, rather than complete, epithelial-mesenchymal phenotype at the tumor bud level, and its connection with tumor proliferation, quiescence, and stemness. Finally, based on recent literature, indicating a co-expression of epithelial and mesenchymal markers in many tumor buds, we posit tumor budding to be a manifestation of this hybrid epithelial/mesenchymal phenotype displaying collective cell migration.