The critical role of tumor size in predicting lymph node metastasis in early-stage colorectal cancer

Abstract

Background

Main purpose of this study is to investigate impact of tumor size on risk of lymph node metastasis (LNM) in pT1-stage colorectal cancer (CRC), focusing on colon, rectosigmoid junction, and rectum.

Method

Patients diagnosed with primary pT1 CRC between 2015 and 2019 were selected from National Cancer Database, utilizing International Classification of Diseases for Oncology, Third Edition (ICD-O-3) codes. We analyzed factors influencing LNM using uni- and multivariate analysis, then isolated tumor size to study its impact on LNM.

Results

In this study of 27,649 pT1-stage tumor patients, we found that 10 ​% of colon, 16 ​% of rectosigmoid junction, and 13 ​% of rectum were LNM+. The study had 14,339 males (51.97 ​%). Mean age was 64.9 (±11.7). In multivariate analysis, sample was adjusted by excluding confounding factors, isolating impact of tumor size on LNM. Analysis for only tumor size, patients with colon tumors >45 ​mm had 53 ​% increased odds of LNM (95 ​% CI [1.06, 2.23], p ​= ​0.03), whereas tumor size did not significantly affect LNM in rectosigmoid and rectum cases, with odds ratios of 2.05 (95 ​% CI [0.82, 5.09], p ​= ​0.12) and 1.62 (95 ​% CI [0.97, 2.71], p ​= ​0.065) respectively, for tumors ≥45 ​mm compared to those <15 ​mm.

Conclusion

This investigation refines predictors of LNM, crucial for tailoring organ-sparing strategies in early-stage CRC management. While tumor size is significant determinant of LNM in colon cancer, early rectal and rectosigmoid cancers may be associated with lower risk of LNM.