Retrospective accuracy analysis of major guidelines and factors for lymph node metastasis of pT1 colorectal cancer

HDG, LVI, TB, and gender (female) are independent risk factors for LNM of T1 CRC. DSI is an excellent negative predictor, although not an independent risk factor. The NCCN/ESMO guideline has medium sensitivity and requires improvement. The JSCCR/FICPG guideline has perfect sensitivity but low specificity, thus exposing patients to many unnecessary surgeries. There is revision potential for current guideline factors, including those beyond current pathological ones, to improve LNM prediction accuracy.