A Novel 4-Tier Classification for Tumor Budding and the Importance of Tumor Invasive Patterns in the Prognosis of Colorectal Cancer.

Background: Colorectal carcinoma (CRC) is a major global health issue, with significant morbidity and mortality. Although the TNM staging system remains the standard for prognosticating CRC, it fails to capture the full complexity of tumor behavior. Tumor budding (TB) and tumor invasive patterns (TIPs) are emerging as promising histopathological markers that may provide additional prognostic insights, particularly in predicting the nodal metastasis (N), lymphovascular invasion (LVI), and perineural invasion (PNI). This study aims to assess the correlation between TB, TIP, and CRC prognosis.

Materials And Methods: This ambidirectional observational study, conducted at our tertiary care center, included 60 biopsy-proven CRC patients, the majority of whom were at stages 2 and 3. Histopathological evaluation of TB and TIP were performed on Hematoxylin and Eosin (H&E) stained slides. TB and TIP categories are then compared against various histopathological parameters. Statistical analysis was performed.

Results: In the 60 CRC cases studied, low TB was observed in 60% of cases, whereas high TB was seen in 5%. TIP analysis showed that 57% of cases had expansile patterns and 35% of cases had infiltrative patterns. A significant association was found between TB and N (p - 0.018) as well as TIP and PNI (p - 0.016). Multivariate analysis revealed that TB remained a strong predictor for N (OR (odds ratio) = 12.8 and p < 0.001). Although not statistically significant, distinct trends were observed between low and zero TB. Our study's findings on TB and TIP align with several historical studies, reinforcing their prognostic significance in CRC. Despite being a small cohort, our study aligns with these findings, emphasizing TB and TIP as critical prognostic markers in CRC.

Conclusion: TB and TIP are valuable prognostic tools in CRC, offering insights into tumor behavior and metastasis potential. Their incorporation into routine histopathological evaluation could enhance prognostic accuracy.