[Risk factors of regional lymph node metastases in pT1 colorectal cancer].

Aim: To identify risk factors of lymph node metastases in patients with pT1 rectal cancer.

Material And Methods: There were 43 patients aged 62.3±11.3 years with pT1 rectal cancer who underwent mesorectal excision in 2012 - 2018. There were 34 (64%) females and 19 (36%) males.

Results: Histological examination revealed SM1-2 in 22/43 (51%) cases, SM3 - in 21/43 (49%) cases. Lymph node metastases were identified in specimens with submucosal invasion: SM3 - in 8/21 (38.1%) cases and SM1-2 - in 3/22 (13.6%) cases (p=0.08). Logistic regression confirmed lymphovascular invasion (p=0.005) and mucosal and/or poorly differentiated carcinoma (p=0.014) as independent predictors of lymph node metastases.

Conclusion: Lymphovascular invasion and poorly differentiated carcinoma are indications for transabdominal mesorectal excision.