Prognostic Significance of Histomorphological Features beyond TNM Staging in Colon Cancer Survival

Colorectal cancer (CRC) is a significant global health challenge, particularly in India where prognosis is poor. While TNM staging is crucial, its limitations necessitate identifying additional histological and morphological factors for risk stratification, especially in early-stage disease where adjuvant therapy decisions are debated.

This retrospective, single-center study analyzed 142 colon adenocarcinoma patients (TNM Stage I-III) who underwent curative resection (2016-2020). Data included demographics, tumor location, TNM stage, and re-reviewed histopathological features such as histological grade, lymphovascular invasion (LVI), perineural invasion (PNI), tumor budding (TB), tumor deposits (TDs), tumor perforation, and tumor-infiltrating lymphocytes (TILs). Overall survival (OS) was assessed with a minimum 3-year follow-up using Kaplan-Meier analysis and log-rank tests.

The cohort was predominantly male, over 40 years age, with a high proportion of right-sided tumors. Late-stage disease significantly correlated with higher histological grade (p=0.009), LVI (p<0.001), PNI (p=0.02), TDs (p=0.001), tumor perforation (p<0.001), and advanced T-stages (p=0.001). Grade 3 TILs were more prevalent in early-stage patients (p=0.004). LVI and PNI were strong negative prognostic factors, while higher TIL grades correlated with better survival. Tumor budding showed no stage association (p=0.91) but correlated with poorer survival.

This study confirms LVI, PNI, and TNM stage as significant predictors of survival. It further highlights tumor budding as an independent marker of biological aggressiveness and suggests high TILs are associated with a robust immune response and improved outcomes in early-stage disease. These findings are crucial for refining risk stratification models and guiding therapeutic decisions in colon cancer.