pT1 colorectal polyps represent an early stage of colorectal cancer with a variable risk of lymph node involvement and recurrence. Treatment selection—endoscopic resection (ER) versus surgery—relies on the presence of high-risk histological features. Although the Japanese Society for Cancer of the Colon and Rectum (JSCCR) criteria are widely applied, their predictive accuracy remains controversial. This study evaluated our center’s experience with pT1 colorectal polyp management and analyzed the association between histological risk factors and oncological outcomes.

We performed a retrospective descriptive study of 154 patients with pT1 colorectal polyps resected between 2010 and 2022. Patients were classified according to initial treatment: ER alone (n=75), ER followed by immediate surgery (ER+S, n=26), or primary surgery (S,n=53). Clinical, histological, and oncologic variables were collected. Univariable logistic regression analyses were used to assess associations between histological features and lymph node metastasis.

Among the 154 patients, 4 developed recurrence and 12 died, none of the deaths directly attributable to the pT1 lesion. All recurrences occurred in the high-risk group. High-risk histological features were present in 72.1% of patients (n=111). Lymph node metastasis was identified in 12 patients, all within the surgically treated groups. Among these, 5 (41.7%) had perineural invasion and 4 (33.3%) had lymphovascular invasion. In the surgical subgroup, both features were independently associated with lymph node metastasis (p=0.01)

ER appears to be a safe and effective treatment for selected pT1 colorectal polyps, even when some high-risk features are present. PNI and LVI emerged as the strongest predictors of lymph node metastasis. These findings support an individualized approach to decision-making, prioritizing histological factors with proven prognostic relevance and potentially reducing unnecessary surgical interventions.