Tumor budding as a novel predictor of occult metastasis in cT2N0 tongue squamous cell carcinoma

Tumor budding is an optimal indictor of occult cervical metastasis in clinical early-stage buccal mucosa squamous cell carcinoma

BACKGROUND

Buccal mucosa squamous cell carcinoma (BMSCC) is an aggressive disease. This study investigated the clinicopathological significance of tumor budding (TB), depth of invasion (DOI), and mode of invasion (MOI) on occult cervical metastasis (CM) of BMSCC.

METHODS

Seventy-one cT1-2N0 BMSCC patients were included in this retrospective study. TB, DOI, MOI, and other clinicopathological features were reviewed. Risk factors for occult CM, locoregional recurrence-free survival (LRRFS), and overall survival (OS) were analyzed using logistic regression and Cox's proportional hazard models, respectively.

RESULTS

Multivariate analysis with the logistic regression model revealed that MOI, DOI, and TB were significantly associated with occult CM in early-stage BMSCC after adjusting for variates. However, multivariate analysis with the Cox's proportional hazard model found only TB to be a prognostic factor for LRRFS (hazard ratio 15.03, 95% confidence interval [CI] 1.94-116.66; p = 0.01; trend test p = 0.03). No significant association was found between MOI, DOI, or TB and OS.

CONCLUSIONS

The optimal predictor of occult CM and prognosis of early-stage BMSCC is TB, which may assist clinicians in identifying patients at high risk of cervical metastasis.

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.

Occult metastasis is no burden factor in oral squamous cell carcinoma patients when adhering to a standardized approach in neck dissection

OBJECTIVES

Management of the neck in patients with oral squamous cell carcinoma (OSCC) is pivotal to oncologic control and survival. However, there is controversy regarding necessity of neck dissection (ND) in patients with clinically node-negative neck. We aimed to assess risk factors for occult metastasis and to explore whether the presence of occult lymph node metastases (LNMs) has an impact on recurrence and survival.

MATERIAL AND METHODS

A retrospective cohort study was performed including patients with primary OSCC who underwent radical tumor resection and ND in a high-volume center adhering to the prevailing German guideline. The ND was performed according to a standardized approach.

RESULTS

Four hundred twenty-one patients with primary surgically treated OSCC were included. The incidence of occult metastasis was 14.49%. A pathological T stage > 1 (multivariate analysis, odds ratio (OR) 3.958, p = 0.042) and the presence of extranodal extension in LNMs (multivariate analysis, OR 0.287, p = 0.020) were identified as independent risk factors for occult metastasis. When comparing patients with and without occult metastasis, there were no significant differences in terms of progression-free survival (log-rank, p = 0.297) and overall survival (log-rank, p = 0.320). There were no cases of ipsilateral neck recurrence. One patient developed contralateral neck metastasis; however, he initially presented with a unilateral pT1 pN0 tumor.

CONCLUSIONS

Overall, our findings suggest that conducting a standardized approach in ND should be applied in terms of management of the neck in order to maintain survival rates and to prevent neck recurrence in OSCC patients.

CLINICAL RELEVANCE

None of the risk factors for occult metastasis can be reliably assessed preoperatively. Although elective ND does not guarantee the complete prevention of neck recurrence, it increases the likelihood of either timely removal of micrometastases or strengthens the justification for adjuvant therapy. Consequently, this approach leads to improvements in clinical outcomes.

Tumor budding is a prognostic factor in head and neck squamous cell carcinoma: A comprehensive meta-analysis and trial sequential analysis

BACKGROUND

Mortality is linked to tumor budding (TB) in certain neoplasms. TB as a relevant histopathological feature is conditioned by tumor site, a specific study on head and neck squamous cell carcinoma (HNSCC) is needed.

METHODS

A comprehensive meta-analysis was undertaken to investigate the relationship between TB and HNSCC-related outcomes.

RESULTS

Overall 42 studies were included. Patients harboring high TB reported an Overall Survival (OS) Hazard Ratio (HR) of 2.63 (95% confidential interval (CI) 2.04-3.39; p-value < 0.001), Disease-free Survival (DFS) HR of 1.88 (95%CI 1.57-2.24; p-value <0.001) and Disease-specific Survival (DSS) HR of 2.14 (95%CI 1.81-2.52; p-value <0.001). Lymph Node Metastasis (LNM) studies harbored null heterogeneity and marked association with TB (Odds Ratio (OR) = 4.48, 95%CI 2.97-6.76; p-value < 0.001). Trial Sequential Analysis (TSA) supported definitive results for DSS.

CONCLUSION

The study has provided compelling evidence that there is a significant association between TB and a worse prognosis for HNSCC.

Significance of tumour budding and invasive characteristics in grading of oral squamous cell carcinoma

Background

Tumour budding has been recognized as a morphologic marker of tumour invasion. Invasive characteristics such as depth of invasion, mode of invasion and worst pattern of invasion are potentially powerful parameters predicting the regional metastasis.

Aim

This study was done to understand the significance of tumour budding and various characteristics of invasion and their impact on grading of oral squamous cell carcinoma.

Materials and Methods

An immunohistochemical study was performed on tissue sections obtained from 34 paraffin-embedded blocks of clinically and histologically diagnosed cases of oral squamous cell carcinoma. The sections were stained with pan cytokeratin and observed under high power magnification.

Results

Tumour budding and the invasive patterns were found to be significant in OSCC. A proposed grading system based on tumour budding and cell nest was found to have a significant correlation with the WHO grading system.

Conclusion

This study demonstrated the importance of using tumour buds as an additional parameter in the grading system and also assessed the importance of invasive patterns, cellular atypia and stromal contents in OSCC.

Predictive value of tumor budding in head and neck squamous cell carcinoma: an update

Head and neck squamous cell carcinoma forms an anatomically and functionally complex group of malignancies. The significant local aggressiveness and frequent regional relapses motivate ongoing research to identify more reliable and sensitive prognostic and predictive biomarkers. One emerging area of cancer biology is the evaluation of tumor budding at the advancing invasive front of various types of epithelial cancers. Recent studies suggest that tumor budding is a relatively common phenomenon in cancer progression and that it may have important prognostic implications for patients due to its potential to provide valuable insights into the biology and clinical behavior of head and neck cancer. In this review, we aim to provide information about tumor budding in head and neck squamous cell carcinoma. Thus, we hope to shed light on the complex biology of these malignancies, as well as aiding diagnostic, classification, and better characterization and thereby, looking for new avenues for improving patient outcomes.

Prediction of cervical lymph node metastasis from immunostained specimens of tongue cancer using a multilayer perceptron neural network

BACKGROUND

Although cervical lymph node metastasis is an important prognostic factor for oral cancer, occult metastases remain undetected even by diagnostic imaging. We developed a learning model to predict lymph node metastasis in resected specimens of tongue cancer by classifying the level of immunohistochemical (IHC) staining for angiogenesis- and lymphangiogenesis-related proteins using a multilayer perceptron neural network (MNN).

METHODS

We obtained a dataset of 76 patients with squamous cell carcinoma of the tongue who had undergone primary tumor resection. All 76 specimens were IHC stained for the six types shown above (VEGF-C, VEGF-D, NRP1, NRP2, CCR7, and SEMA3E) and 456 slides were prepared. We scored the staining levels visually on all slides. We created virtual slides (4560 images) and the accuracy of the MNN model was verified by comparing it with a hue-saturation (HS) histogram, which quantifies the manually determined visual information.

RESULTS

The accuracy of the training model with the MNN was 98.6%, and when the training image was converted to grayscale, the accuracy decreased to 52.9%. This indicates that our MNN adequately evaluates the level of staining rather than the morphological features of the IHC images. Multivariate analysis revealed that CCR7 staining level and T classification were independent factors associated with the presence of cervical lymph node metastasis in both HS histograms and MNN.

CONCLUSION

These results suggest that IHC assessment using MNN may be useful for identifying lymph node metastasis in patients with tongue cancer.

The Emerging Impact of Tumor Budding in Oral Squamous Cell Carcinoma: Main Issues and Clinical Relevance of a New Prognostic Marker

Tumor Budding (TB) represents a single cancer cell or a small cluster of less than five cancer cells on the infiltrative tumor front. Accumulating evidence suggests TB is an independent prognostic factor in oral squamous cell carcinoma (OSCC). However, its exact role is not yet elucidated, and a standardized scoring system is still necessary. The study aims to extensively review the literature data regarding the prognostic role of TB in OSCC. The results of TB are an independent prognostic factor of poor survival outcomes in OSCC. To date, the manual detection of hematoxylin and eosin-staining or pancytokeratin-immunostaining sections are the most commonly used methods. Between the several cut-offs, the two-tier system with five buds/field cut-offs provides better risk stratification. The prognostic role of the BD model in predicting survival outcomes was extensively validated; however, the inclusion of DOI, which is already a staging parameter, encouraged other authors to propose other models, integrating TB count with other adverse risk factors, such as the tumor–stroma ratio and tumor-infiltrated lymphocytes. The prognostic relevance of TB in OSCC highlights its evaluation in daily pathological practice. Therefore, the TB detection method and the TB scoring system should be validated based on tumor stage and site.

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.

The prognostic role of histologic grade, worst pattern of invasion, and tumor budding in early oral tongue squamous cell carcinoma: a comparative study

Major pathology guidelines often mandate stating the histologic grade as a component of the pathology report for various types of cancer. However, the prognostic value of histologic grade in head and neck squamous cell carcinoma (HNSCC) is controversial at best, and there is a need for more reliable prognostic histologic factors to better stratify and manage patients with HNSCC. In this study, we compared three relevant histopathologic features (histologic grade, worst pattern of invasion (WPOI), and tumor budding) in a large single-center retrospective cohort of early oral tongue squamous cell carcinoma (OTSCC) with tumor greatest dimension ≤ 4 cm. Only histologic grade predicted distant metastasis free survival (DMFS) on univariate analysis. Tumor budding was associated with nodal metastasis, overall survival (OS), regional recurrence-free survival (RRFS), and DMFS and was a significant predictor for nodal metastasis on the multivariable logistic regression model. WPOI 5 was associated with high frequency of nodal metastasis and shortened OS and was an independent adverse prognostic factor for OS on multivariate analysis using the Cox proportional hazards model. WPOI and tumor budding were prognostically more relevant than histologic grade. Consideration should be given to include WPOI and tumor budding in the pathology reporting of OTSCC.

Can MRI-derived depth of invasion predict nodal recurrence in oral tongue cancer?

OBJECTIVES

To evaluate the prognostic value of preoperative radiological findings for nodal recurrence in clinically node-negative (cN0) patients with oral tongue squamous cell carcinoma (SCC).

METHODS

The study population consisted of 52 patients with cT1-2N0 oral tongue SCC classified according to the 7th edition of the Union for International Cancer Control (UICC) staging system. The subjects had undergone preoperative radiological examinations, including magnetic resonance imaging (MRI) and ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography. All patients were treated with local resection and watchful waiting for neck management. Using an unpaired t test, Pearson's chi-squared test, and the Kaplan-Meier method, the MRI-derived depth of invasion (DOI), the standardized uptake value (SUV) on FDG-PET, and the T stage according to the 7th and 8th UICC were assessed as prognostic factors.

RESULTS

The MRI-derived DOI was recorded as ≤ 5 mm in 24 patients and > 5 mm in 28 patients. During the follow-up period, nine patients exhibited nodal recurrence, with the MRI-derived DOI being significantly higher in patients with positive than in those with negative (p = 0.011). The SUV was not significant. Five-year cumulative nodal recurrence probabilities were 4.5% for patients with an MRI-derived DOI ≤ 5 mm, while it was 32.1% for > 5 mm (p = 0.013). Although the T classifications were not significant, none of our patients whose T stage according to the 8th UICC was T1 suffered nodal recurrence.

CONCLUSIONS

MRI-derived DOI can predict nodal recurrence, while preoperative information may assist in treatment planning for oral tongue SCC.

Predictive Value of Occult Metastasis and Survival Significance of Metabolic Tumor Volume Determined by PET-CT in cT1-2N0 Squamous Cell Carcinoma of the Tongue

Objectives

Our goal was to analyze the possibility of using metabolic tumor volume (MTV) to predict occult cervical metastasis and survival in cT1-2N0 squamous cell carcinoma (SCC) of the tongue.

Methods

Data on the primary tumor MTV and cervical node status as determined by the maximum standardized uptake value were retrieved. The sensitivity and specificity in predicting occult metastasis were calculated with a fourfold table. Associations between occult metastasis and clinicopathological variables were evaluated by univariate and multivariate analyses. The main study endpoints were locoregional control (LRC) and disease-specific survival (DSS).

Results

A total of 24 (20.3%) of 118 patients had occult metastasis. An MTV cutoff value of 4.3 cm³ showed a sensitivity of 50.0% and a specificity of 76.6% in predicting occult metastasis. The sensitivity and specificity of PET-CT in predicting occult metastasis in cT1 tumors were 66.6 and 89.8%, respectively, with values of 83.3 and 67.3%, respectively, when combined with the MTV. The sensitivity and specificity of PET-CT in predicting occult metastasis in cT2 tumors were 72.2 and 82.2%, respectively, with values of 88.9 and 57.8%, respectively, when combined with the MTV. Patients with MTV ≥4.3 cm³ had a higher occult metastasis rate than patients with MTV <4.3 cm³. The 5-year LRC and DSS rates were 86 and 94%, respectively, in patients with MTV <4.3 cm³ and 54 and 72%, respectively, in patients with MTV ≥4.3 cm³. Both differences were found to be significant in univariate and multivariate analyses.

Conclusions

MTV ≥4.3 cm³ was associated with an increased probability of occult metastasis and lower LRC and DSS rates in early-stage SCC of the tongue.

Predictive significance of tumor budding in postoperative liver metastasis of pancreatic neuroendocrine tumors

BACKGROUND

Although pancreatic neuroendocrine tumors (PNETs) are considered indolent tumors, nearly half of cases metastasize to the liver, which can be lethal. However, effective indicators to predict aggressive behavior have not been well-established.

METHODS

In the current study, we explored the prognostic significance of tumor budding in Grade 1-2 PNETs. Hematoxylin-eosin and immunohistochemically stained slides of surgically removed Grade 1-2 PNETs were evaluated.

RESULTS

Tumor budding, a histomorphological parameter that corresponds to single cells or small cell clusters (<5 cells), was classified as low (0-10 buds) and high (>10 buds) grade. We observed that tumor budding was correlated with aggressive histopathological parameters, such as T stage, lymph node status, metastasis, and vascular invasion (p < .05). Univariate and multivariate analyses showed that high-grade budding was an independent predictive factor for postoperative liver metastasis (p = .012). Moreover, Grade 1-2 PNETs with high-grade budding was associated with worse overall survival and disease-free survival (p = .0015 and p = .0041, respectively).

CONCLUSIONS

We conclude that tumor budding may serve as a valuable parameter in the risk stratification of postoperative liver metastasis and that incorporating tumor budding into histopathological reports may aid in appropriate clinical management.

Prognostic Role of Tumor Budding in Carcinoma Tongue: A Systemic Review and Meta-Analysis

Introduction  Tumor budding is defined as a cluster of cells that invade the stroma. This has recently been studied to be associated with lymph node metastasis (LNM) and poor overall survival (OS) rate. The reliability and reproducibility of this histopathological feature make it a valid prognostic indicator in tongue carcinomas, which often have an unpredictable prognosis. The objective of this study was to group the studies that elucidate the prognostic role of tumor budding in tongue cancers. Methods A systematic database search was performed in MEDLINE, Embase, and Google Scholar for relevant studies that reported tumor budding in tongue cancer. The relevant articles were independently screened by two authors for selection and data extraction. As a result, a list of such studies, clinical trials, and references, published in English up to March 2020, was obtained, and a total of 1448 patients in nine studies were included in this meta-analysis. Statistical analysis was conducted using RevMan software 5.3 (The Nordic Cochrane Centre, Cochrane Collaboration, Copenhagen). Results A higher tumor budding score was significantly correlated with LNM (hazard ratio (HR): 3.07; 95% confidence interval (CI): 2.08-4.52; p≤.00001) and poor OS (HR: 2.40; 95% CI: 1.84-3.14; p≤.00001) in tongue cancer. Conclusions Our present study demonstrates that tumor budding is an independent predictor of LNM and OS in tongue cancer. Tumor budding should be considered a parameter in future oncological staging systems.

Staging and grading of oral squamous cell carcinoma: An update

Oral squamous cell carcinoma (OSCC) is a common malignancy of the head and neck region. OSCC has a relatively low survival rate and the incidence of the disease is increasing in some geographic areas. Staging and grading of OSCC are established prerequisites for management, as they influence risk stratification and are the first step toward personalized treatment. The current AJCC/UICC TNM staging (8th edition, 2017) of OSCC has included significant modifications through the incorporation of depth of invasion in the T stage and extracapsular spread/extranodal extension in the N stage. Further modifications for AJCC 8 have been suggested. On the other hand, the World Health Organization (WHO) classification (4th edition, 2017) still endorses a simple, differentiation-based histopathologic grading system of OSCC (despite its low prognostic value) and ignores factors such as tumor growth pattern and dissociation, stromal reactions (desmoplasia, local immune response), and tumor-stroma ratio. The various controversies and possible developments of the current staging and grading criteria of OSCC are briefly discussed in this update together with possible applications of artificial intelligence in the context of screening and risk stratification.

A Proposal to Revise the Histopathologic Grading System of Early Oral Tongue Cancer Incorporating Tumor Budding

The World Health Organization (WHO) grading system has a low prognostic value for early-stage oral tongue squamous cell carcinoma; greater prognostic power has been shown with tumor budding analysis. In this study, we combined tumor budding analysis with histopathologic grading according to WHO 2017. In our proposal, a revised grade I tumor is defined as a "well differentiated cohesive tumor"; revised grade II as a "moderately differentiated and/or slightly dissociated tumor"; and revised grade III as a "poorly differentiated and/or dissociated tumor." We evaluated the prognostic value of this proposed grading system in a multicenter cohort of 311 cases of early oral tongue squamous cell carcinoma. The proposed grading system showed significant prognostic value in multivariable analysis for disease-specific survival with a hazard ratio of 3.86 and a 95% confidence interval of 1.36-10.9 (P=0.001). For disease-free survival, the proposed grading system showed good predictive power in multivariable analysis (hazard ratio, 2.07; 95% confidence interval, 1.00-4.27; P=0.009). The conventional WHO grading system showed a low prognostic value for disease-specific survival and disease-free survival (P>0.05). In conclusion, the prognostic power of the WHO histopathologic grading improved significantly with incorporation of tumor budding. Our proposed grading system can be easily included in pathology reports.

Pre-operative cellular dissociation grading in biopsies is highly predictive of post-operative tumour stage and patient outcome in head and neck squamous cell carcinoma

BACKGROUND

Pre-operative treatment planning in head and neck squamous cell carcinoma (HNSCC) is mainly dictated by clinical staging, which has major shortcomings. Histologic grading is irrelevant due to its lack of prognostic impact. Recently, a novel grading termed Cellular Dissociation Grade (CDG) based on Tumour Budding and Cell Nest Size was shown to be highly prognostic for resected HNSCC. We aimed to probe the predictive and prognostic impact of CDG in the pre-operative biopsies of HNSCC.

METHODS

We evaluated CDG in n = 160 pre-therapeutic biopsies from patients who received standardised treatment following German guidelines, and correlated the results with pre- and post-therapeutic staging data and clinical outcome.

RESULTS

Pre-operative CDG was highly predictive of post-operative tumour stage, including the prediction of occult lymph node metastasis. Uni- and multivariate analysis revealed CDG to be an independent prognosticator of overall, disease-specific and disease-free survival (p < 0.001). Hazard ratio for disease-specific survival was 6.1 (11.1) for nG2 (nG3) compared with nG1 tumours.

CONCLUSIONS

CDG is a strong outcome predictor in the pre-treatment scenario of HNSCC and identifies patients with nodal-negative disease. CDG is a purely histology-based prognosticator in the pre-therapeutic setting that supplements clinical staging and may aide therapeutic stratification of HNSCC patients.

Long-term disease-free survival in surgically-resected oral tongue cancer: a 10-year retrospective study

Early and loco-regionally advanced oral tongue squamous cell carcinoma (OTSCC) can be treated by surgery alone or followed by adjuvant radiotherapy or chemoradiotherapy. Nevertheless, up to 40% of patients develop tumour relapse. The aim of our study is to investigate the clinical and pathological features associated with reduced disease-free survival (DFS) in a cohort of surgically-resected OTSCC patients. One hundred and six patients surgically resected for OTSCC were retrospectively identified from clinical records. DFS was calculated according to the Kaplan–Meier method and differences between variables were assessed with Log-Rank test. A multivariable Cox regression model was used to analyse the impact of different prognostic factors on DFS. After a median of follow-up of 8.9 years, 22 events, including 11 deaths, were observed. Overall, the 5-year DFS-rate was 87.4%. The presence of extra-nodal extension (p = 0.023) and perineural invasion (p = 0.003) were significantly correlated with shorter DFS (in univariate analysis). In multivariable analysis, extra-nodal extension and perineural invasion confirmed their role as independent prognostic factors associated with an increased risk of disease recurrence [hazard ratio (HR) 2.87, 95% CI 1.11-7.42, p = 0.03; HR 3.85, 95% CI 1.49-9.96, p = 0.006, respectively]. p16 and p53 expressions in tumour cells were detected in 12% (n = 9) and 46% (n = 40) of cases, respectively. No differences in DFS were observed between p16+ and p16- (p = 0.125) and between p53+ and p53- tumours (p = 0.213). In conclusion, radical surgery, eventually followed by adjuvant radiotherapy or chemo-radiotherapy, can achieve high cure rates in OTSCC. After long-term follow-up, perineural invasion and extra-nodal extension confirmed their role as prognostic factors associated with reduced DFS in OTSCC patients.

Hallmarks of cancer: Tumor budding as a sign of invasion and metastasis in head and neck cancer

Invasion and metastasis are hallmarks of cancer. The concept of tumor budding at tumor-host interface has been documented in many carcinomas. A growing body of evidence indicates that tumor budding is a sign of invasion and early step for metastasis of many epithelial cancers including head and neck squamous cell carcinoma (HNSCC). In addition, recent research has underlined the importance of tumor budding as a promising prognosticator in HNSCC. This review summarizes the findings regarding tumor budding in HNSCC and focuses on the role of tumor budding in invasion and metastasis. Also, we highlight the prognostic significance of tumor budding in HNSCC and its potential for improving clinical decision making in terms of recommending optimal individualized treatment for this patient population.

Validation of the International Tumor Budding Consensus Conference (2016) recommendations in oral tongue squamous cell carcinoma

BACKGROUND

Tumor budding is a valuable prognostic marker in oral tongue squamous cell carcinoma (OTSCC) but lacks a standardized scoring system. The aim of this study was to evaluate the prognostic value of tumor budding for OTSCC patients based on the scoring system recommended by the International Tumor Budding Consensus Conference (ITBCC) 2016.

METHODS

Tumor budding was scored as ITBCC recommended in 255 patients with OTSCC. Then, associations between tumor budding and clinicopathologic parameters were examined. Among them, 136 patients with follow-up data available were used to evaluate overall survival (OS) by the Kaplan-Meier method. Prognostic value of tumor budding was assessed by Cox regression analysis. The inter-observer and intra-observer agreement was calculated by the kappa statistic.

RESULTS

Tumor budding score was associated with lymph node metastasis, differentiation, invasive pattern, lymphoid infiltrate, tumor relapse, invasive depth, and reduced OS in OTSCC patients. The Cox analysis showed high budding score was an independent prognostic factor in patients with all clinical stage and patients with clinical early-stage OTSCC. The high kappa values were achieved in intra-observer and inter-observer.

CONCLUSIONS

International Tumor Budding Consensus Conference scoring system is a simple, reliable, and reproducible method to measure tumor budding in OTSCC, which should be included in the routine pathological report.

Novel prognostic histopathological grading system in oral squamous cell carcinoma based on tumour budding and cell nest size shows high interobserver and intraobserver concordance

AIMS

Squamous cell carcinoma of the oral cavity (OSCC) is a common tumour entity with a variable, partially highly aggressive clinical course. Recently, we proposed a novel (three-tiered) clinically useful grading scheme strongly associated with patient outcome in OSCC, consisting of a sum score of the histomorphological patterns tumour budding and cell nest size which outperforms WHO based grading algorithms currently in use. The aim of our study was to probe for interobserver and intraobserver reliability of this novel grading system.

METHODS

108 OSCC were retrospectively scored according to the proposed grading scheme by three independent pathologists-two experienced head and neck pathologists and one pathologist in training-blinded to each other's scoring results.

RESULTS

The Cohen's Kappa (κ) values for concordance rates between experienced pathologists were κ=0.97 for the overall grade, κ=0.97 for budding activity and κ=0.91 for cell nest size, indicating a strong interobserver reliability of our proposed grading system. Initial interobserver agreement was markedly lower with the pathologist in training (κ=0.55 for overall grade) but improved significantly after a training session (κ=0.87 for overall grade). Intraobserver concordance was high (κ=0.95 for overall grade), indicating a high reproducibility of the algorithm.

CONCLUSIONS

In conclusion, our study indicates that OSCC grading based on our proposed novel scheme yields an excellent inter-reader and intrareader agreement, further supporting the suitability of this grading system for routine pathological practice.