Infiltrating Tumor Border Configuration is a Poor Prognostic Factor in Stage II and III Colon Adenocarcinoma.

Introduction: Tumor border configuration (TBC) is a prognostic factor in colorectal adenocarcinoma; however, the significance of TBC is not well-documented in colon adenocarcinoma alone.

Objective: Our aim was to study the effect of TBC on overall and disease-free survival in stage II and III colon adenocarcinoma.

Methods: We included patients with stage II and III colon adenocarcinoma who were surgically treated at a tertiary medical center between 2004 and 2015, to ensure long-term follow-up. Patients were stratified into four groups based on stage and TBC. A Cox regression was used to model the relationship of groups while accounting for relevant confounders.

Results: The cohort consisted of 700 patients (371 stage II and 329 stage III). Infiltrating TBC was statistically significantly associated with stage (p < 0.001) and extramural vascular invasion (p < 0.001), but not histologic grade (p = 0.7). Compared with pushing TBC, infiltrating TBC increased the hazard of death by a factor of 1.8 [95% confidence interval (CI) 1.4-2.4; p < 0.001] and 1.7 (95% CI 1.3-2.2; p < 0.001). The hazard of death in patients with stage II disease (infiltrating TBC) or stage III disease (pushing TBC) was not significantly different (adjusted hazard ratio 1.1, 95% CI 0.7-1.7; p = 0.8).

Conclusion: Infiltrating TBC is a high-risk feature in patients with stage II and III colon adenocarcinoma. Stage II disease patients with infiltrating TBC and who are node-negative should be considered for adjuvant chemotherapy.