TUMOUR BUDDING and its correlation with other prognostic markers

tumour budding and its correlation with other prognostic markers

1. Title : Evaluation of Tumor Budding in Oral Squamous Cell Carcinom a A Correlation with Histomorphological Prognostic Markers and Epithelial-Mesenchymal Transition Authors : Kusum Yadav, Tejasvita Singh, Kachnar Varma, Mudita Bhargava, Vatsala Misra Institution : Department of Pathology, M.L.N. Medical College, Prayagraj, Uttar Pradesh, India Journal : Indian Journal of Pathology and Microbiology, 2023 DR.JEENA RAJ DEPARTMENT OF PATHOLOGY

2. Oral squamous cell carcinoma Common malignancy in the oral cavity-->in Southeast Asia. High prevalence of risk factors-->smokeless tobacco use. Despite diagnostic advancements-->5-year survival rate remains low

3. Need for better prognostic markers Current histopathological markers (tumor grade, depth of invasion, lymph node status) --> limited reliability. Emerging marker: Tumor Budding (TB).

4. Tumour Budding (TB)- Overview Isolated tumour cells OR Tumour cells in small clusters (<5 cells) in the stroma at the invasive margin of the tumour Linked to epithelial-mesenchymal transition (EMT) – a hallmark of metastasis.

5. Prognostic significance Established as an independent prognostic factor --> colorectal, lung, and breast cancers. Investigated in OSCC --> role in invasion, metastasis, and survival prediction.

6. Objective 1.To evaluate Tumour Budding in OSCC 2. Correlation with histomorphological markers and Epithelial-Mesenchymal Transition (EMT).

7. Study Design and Methods Sample Size: 200 cases of OSCC from different oral mucosa sites (buccal mucosa, tongue, oropharynx)--> 2 years Techniques: Hematoxylin and Eosin (H&E) --> initial tumor budding assessment. Immunohistochemistry (IHC) -->Cytokeratin AE1/AE3 to enhance detection of Tumour Budding. Markers for EMT : Vimentin (mesenchymal marker), E-cadherin (epithelial marker).

8. TB Grading: Low TB: ≤5 buds/10 high power fields (HPF). High TB: >5 buds/10 HPF. Comparison of H&E and IHC Results: IHC staining for Cytokeratin AE1/AE3 --> gold standard due to its higher accuracy in identifying tumor buds.

9. Comparison of TB intensity with newer histomorphological prognostic markers 1. Tumor Grade High TB Intensity --> associated with poor tumor differentiation. Moderately differentiated tumors: 80.5% had high TB intensity. Poorly differentiated tumors: 71.4% had high TB intensity. The association between tumor grade and TB intensity was statistically significant (p < 0.0001).

10. 2. Lymphovascular Invasion (LVI) High TB intensity --> higher occurrence of lymphovascular invasion (LVI). 93.75% of tumors with LVI had high TB intensity. This association was highly significant (p < 0.0001).

11. 3. Depth of Invasion (DOI) DOI--> depth of tumor penetration from the adjacent normal mucosa to the deepest point of invasion. Depth of invasion Description D1 Tumor invasion depth ≤ 5 mm D2 Tumor invasion depth between 5-10 mm D3 Tumor invasion depth > 10 mm

12. TB intensity--> strongly with depth of invasion: Tumors with DOI >10 mm had a high TB intensity in 82.9% of cases. The association between DOI and TB intensity was statistically significant (p = 0.0027).

13. 4.Lymph Node Status Although high TB intensity was observed more frequently in tumors with lymph node involvement The association was not statistically significant (p = 0.073) .

14. 5.Host Lymphocyte Response (HLR) No statistically significant association between TB intensity and host lymphocyte response (p = 0.433). Moderate to heavy HLR--> seen in both low and high TB cases without significant differences.

15. 6.Pattern of Invasion (POI) 5 patterns based on the invasive tumor front : PATTERN OF INVASION DESCRIPTION POI 1 (Broad pushing) Tumor shows a broad, pushing margin with a smooth outline. POI 2 (Finger-like projections) Tumor invades the stroma with broad finger-like projection s POI 3 (>15 cells per tumor island ) Tumor islands with more than 15 cells at the invasive front POI 4 (<15 cells per tumor island) Tumor islands with fewer than 15 cells at the invasive front. POI 5 (Isolated cells) POI 5 (Isolated cells)

16. TB intensity was strongly associated with more aggressive patterns of invasion (POI). POI 4 and 5 (which include isolated cells and small islands of less than 15 cells) were significantly linked to high TB intensity (p < 0.0001). This confirms the aggressive nature of tumors with high TB intensity.

17. Epithelial-Mesenchymal Transition (EMT)? E pithelial cells lose their characteristics and gain mesenchymal traits --> migration and invasion. Epithelial Traits: Strong cell-cell adhesion (E-cadherin) - - >90% Polarized, structured tissue architecture Mesenchymal Traits: Enhanced migratory capacity Invasive properties Loss of epithelial markers and gain of mesenchymal markers (Vimentin : ≥ 10%)

18. Epithelial-Mesenchymal Transition (EMT) Role of EMT in Cancer Progression: Loss of cellular adhesion & increased mobility Markers: E-Cadherin: Downregulated in TB Vimentin: Upregulated - -> promoting cellular mobility and invasion.

19. EMT and Tumor Budding E-cadherin: Membrane expression reduced in high TB cases (82.6% of high TB tumors). Vimentin: Upregulated in 42% of high TB cases. Conclusion : TB is associated with EMT --> highlighting its role in tumor aggressiveness and poor prognosis.

20. Results: Clinicopathological Profile showing tumour budding Demographics: Majority of patients were >40 years old (67.5%). Male predominance (81.5%). Tobacco consumption history in 59% of cases. Tumor Characteristics: Tumor sizes: 46% were 2–4 cm. Buccal mucosa (50%) was the most common site. Histological grading: 48% were moderately differentiated OSCC. Lymphovascular invasion (LVI) in 30% of cases.

21. Results: Tumor Budding Assessmen t Key Findings: TB was found in 77% of cases --> 57.14% showing high TB intensity on H&E. High TB cases increased to 64.9% when assessed with IHC. High TB intensity correlates with: 1. Tumor grade (moderate ly /poorly differentiated tumors showed more TB). 2. Depth of invasion and lymphovascular invasion. 3. Upregulation of Vimentin and reduced E-cadherin expression in high TB cases --> EMT involvement.

22. Correlation with Prognostic Markers Significant associations: High TB correlated --> poor differentiation (Grade 3 tumors), depth of invasion (DOI), and LVI. Lymphovascular invasion : High TB cases had a significantly higher incidence of LVI. Depth of invasion : As DOI increased, TB intensity also increased (P = 0.0027).

23. Histopathological markers: Pattern of invasion (POI), particularly worst POI (WPOI), was associated with high TB. Strong predictor for poor prognosis

24. Discussion Key Findings: High TB in OSCC is significantly associated with adverse histopathological feature s--> poor differentiation & increased invasion depth. TB as a marker of EMT --> higher tumor invasiveness & metastatic potential.

25. Clinical Implications: Use of TB as a reliable prognostic marker for OSCC in routine practice IHC for Cytokeratin AE1/AE3 improves detection and should be incorporated in TB evaluation.

26. Conclusion Tumor Budding: Serves as an independent, significant marker of poor prognosis in OSCC. Associated with EMT, reinforcing its role in tumor invasion and metastasis. Recommendations: Incorporate IHC in routine diagnostics to improve TB assessment. Further studies needed to explore targeted therapies for EMT-positive cases.

27. References Yadav K., et al. (2023). Evaluation of tumor budding and its correlation with histomorphological prognostic markers in OSCC. Indian Journal of Pathology & Microbiology.

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