Colorectal cancers (CRC) extending beyond the muscularis mucosae and invading the submucosa without extending beyond it are classified as pT1.

Among these, a number of lesions presenting pejorative criteria, notably histopathological, have a significant risk of lymph node invasion, and are therefore candidates for partial colectomy with lymph node dissection. Tumors deemed to be at low risk of lymph node involvement can be treated by endoscopy alone.

It should be noted that further surgical intervention is not without comorbid consequences, and that a significant proportion of post-surgical surgical specimens are free of cancerous lesions.

The aim of this study is therefore to analyze the current histopathological criteria predictive of lymph node invasion, in order to more accurately select candidates for surgical management.

Inclusion Criteria:

• Consecutive patients with pT1 colorectal cancer (of adenocarcinoma subtype only) diagnosed from January the 1st, 2009 to December the 31st, 2020, with first endoscopic resection, in the area of Finistère (France)

Exclusion Criteria:

• other than adenocarcinoma
• other than T1
• primary surgical management
• neoadjuvant treatment
• refusal to data collection

pT1 colorectal cancer (of adenocarcinoma subtype only) diagnosed from January the 1st, 2009 to December the 31st, 2020, with first endoscopic resection, in the area of Finistère (France)

All collected data that underlie results in a publication

Data will be available beginning three years and ending fifteen years following the final study report completion

Data access requests will be reviewed by the internal committee of Brest UH. Requestors will be required to sign and complete a data access agreement