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

Microvascular density analysis and histological parameters of oral cancer progression

OBJECTIVES

This study aimed to investigate the role of blood and lymphatic microvascular density in the progression of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

The sample was composed of 54 cases of OSCC. The immunoexpression to anti-alpha-smooth muscle actin (α-SMA) and to anti-endoglin (CD105) was used to determine the microvessel density (MVD); anti-podoplanin (D2-40) was used to assess the lymphatic vessel density (LVD); vascular endothelial growth factor (VEGF) was evaluated in malignant cells. The histological differentiation, the worst pattern of invasion (WPOI), tumour thickness and tumour budding (TB) intensity were assessed using haematoxylin-eosin and anti-pan-cytokeratin (AE1/AE3). Patients' age and sex, TNM classification and follow-up time were collected from the medical records.

RESULTS

MVD markers presented a similar pattern of expression in blood vessels. However, only α-SMA + MVD was significantly higher among women and in tumours ≤4 cm. LVD was lower in tumours with lymph node metastasis. Regarding the histological parameters, high TB intensity was associated with histological differentiation, advanced clinical stage, greater tumour thickness and reduced disease-free survival. No difference was found in VEGF.

CONCLUSIONS

The decrease in OSCC LVD could be related to pathological node involvement, whereas high TB intensity could indicate OSCC progression and worse patient outcomes.

New Histopathologic Risk Model for Early T-stage Oral Squamous Cell Carcinoma: Focusing on a Modified Worst Pattern of Invasion System and a New Tumor Budding Score

Oral squamous cell carcinoma (OSCC) is treated based on the TNM staging. However, early T-stage OSCC still exhibits substantial nodal metastasis and death rates. Recent literature highlights the independent prognostic value of worst pattern of invasion (WPOI) and tumor budding in OSCC. Nevertheless, WPOI-5 is uncommon in early T-stage OSCC, and the definitions of tumor budding and WPOI-4 overlap. Moreover, WPOI assessment is subjective, and tumor budding evaluation varies across studies. To address these limitations, we aimed to develop a modified WPOI system and a novel tumor budding scoring system that assesses single cells and high-density tumor budding. We also evaluated a new histopathologic risk model for early T-stage OSCC. The study cohort comprised 37 pT1 and 64 pT2 OSCCs. The modified WPOI demonstrated superior interobserver agreement compared with the original system (κ value: 0.98 vs. 0.53). In the multivariate analysis, modified WPOI and tumor budding score were independent prognostic factors for nodal metastasis and disease-free survival, while modified WPOI predicted disease-specific survival. By integrating these factors, our risk model stratified the patients into 3 groups. Notably, the intermediate-risk and high-risk groups exhibited significantly higher rates of nodal metastasis, recurrence, and tumor-related death. Conversely, none in the low-risk group had nodal metastasis or succumbed to the disease. Our model offered simplified scoring and potentially improved prognostic predictions. In conclusion, we've developed a modified WPOI system, a new tumor budding scoring system, and a reliable risk model that classifies early T-stage OSCC patients into distinct risk groups with significant prognostic differences.

High-grade tumor budding is a risk factor for survival in patients with laryngeal squamous cell carcinoma

OBJECTIVE

With the increasing incidence and mortality of laryngeal squamous cell carcinoma worldwide, researchers continue to search for novel prognostic factors and treatment methods for preventing early laryngeal squamous cell carcinoma from becoming advanced laryngeal squamous cell carcinoma. This study aims to determine if tumor budding is an independent risk factor associated with the survival of patients with laryngeal squamous cell carcinoma.

METHODS

268 cases of laryngeal squamous cell carcinoma were studied, and tumor budding was analyzed for associations with clinicopathological features and clinical outcomes.

RESULTS

Tumor budding was divided into low-grade tumor budding (0-6/0.785 mm2) and high-grade tumor budding (≥7/0.785 mm2) based on the results of the receiver operating characteristics curve analysis. Logistic regression analysis showed that smaller tumor cell nests, the low levels of tumor-infiltrating lymphocytes, and higher pathological T staging were the risk factors for high-grade tumor budding (p < 0.05). In the low-grade tumor budding group, there was no statistic difference in survival between patients without tumor budding and those with 1-6/0.785 mm2 tumor budding. Multivariate survival analysis showed high-grade tumor budding (p < 0.001) was independent prognostic factors for disease-free survival and overall survival in laryngeal squamous cell carcinoma. High-grade tumor budding was also an independent prognostic factor for disease-free survival (p = 0.037) and overall survival (p = 0.009) in T1-2N0 laryngeal squamous cell carcinoma.

CONCLUSIONS

Smaller tumor cell nests, the low levels of tumor-infiltrating lymphocytes, and higher pathological T staging were closely associated with high-grade tumor budding in laryngeal squamous cell carcinoma. High-grade tumor budding may be an adverse risk factor that affects not only the disease-free survival and overall survival of laryngeal squamous cell carcinoma patients but also the survival of T1-2N0 laryngeal squamous cell carcinoma patients.

LEVEL OF EVIDENCE

Level 4.

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.