Predictive relevance of lymphovascular invasion in T1 colorectal cancer before endoscopic treatment

Background and aim  The depth of tumor invasion is currently the only reliable predictive risk factor for lymph node metastasis before endoscopic treatment for colorectal cancer. However, the most important factor to predict lymph node metastasis has been suggested to be lymphovascular invasion rather than the depth of invasion. Thus, the aim of this study was to investigate the predictive relevance of lymphovascular invasion before endoscopic treatment. Methods  The data on pT1 colorectal cancers that were resected endoscopically or surgically from 2007 to 2015 were retrospectively reviewed. The cases were categorized into two groups: positive or negative for lymphovascular invasion. The following factors were evaluated by univariate and multivariate analyses: age and sex of the patients; location, size, and morphology of the lesion; and depth of invasion. Results  The positive and negative groups included 229 and 457 cases, respectively. Younger age ( P P  = 0.01), non-LST (LST: laterally spreading tumor) ( P P P  65 years, OR, 1.81; 95 %CI, 1.29 – 2.53), presence of depression (OR, 1.97; CI, 1.40 – 2.77), non-LST features (OR, 1.50; CI, 1.04 – 2.15), and pT1b (OR, 3.08; CI, 1.91 – 4.97) were associated with lymphovascular invasion. Conclusion  Younger age, presence of depression, T1b, and non-LST are associated with lymphovascular invasion. Therefore, careful pathological diagnosis and surveillance are necessary for lesions demonstrating any of these four factors.