Endoscopic Versus Surgical Treatment for T1 Colorectal Cancer

Endoscopic Versus Surgical Treatment for T1 Colorectal Cancer: a Population-based Cohort Study

The implementation of population screening programs for colorectal cancer (CRC) has led to a considerable increase in the prevalence T1 CRC originating on polyps amenable by endoscopy. The benefits of secondary oncological surgery in terms of disease free survival are not well established.

Hypothesis: The characteristics of the individuals and the polyp (endoscopic, histological) should allow us to discriminate T1 CRCs that may benefit from secondary surgery from those that only require local treatment. With the current criteria, the management of patients with T1 CRC is suboptimal since a high proportion of patients are refered for unnecessary surgeries without a clear benefit in terms of survival. Molecular signatures can help to discriminate those patients with good prognosis that do not require secondary surgery nor cancer related follow up.

The primary objective of the study is to compare the effect of oncological surgery versus local treatment for the management of polyps with T1 CRC in relation to disease-free survival and morbi-mortality of the therapeutic procedure. We will also validate molecular signatures in endoscopic samples for the prediction of lymph node metastasis and survival. Methodology: Clinical Study: Retrospective population-based cohort study that will include baseline clinical and follow up data of more than 1400 T1 CRCs in at least 10 Spanish autonomous communities from 2007 to 2017. A centralized pathological review will be carried out by a group of expert pathologists. Inter and intraobserver variability for histological staging will be assessed. A predictive model will be created to discriminate individuals with high probability of receiving surgical and local treatment. For those patients who have a similar probability range, the results in progression-free survival and adverse events will be compared. Translational phase: A 5miRNAs and 8mRNA signature predictive of lymph node metastasis will be assessed in 200 endoscopic samples and related with prognosis.

Inclusion Criteria:

- All patients diagnosed with pT1 CRC will be included, regardless of endoscopic features, treatment received and lymph node staging

Exclusion Criteria:

• CRC with other histology than adenocarcinoma
• Patients with hereditary syndromes of CRC (Lynch syndrome, classical familial adenomatous polyposis) or inflammatory bowel disease.
• Synchronous CRC
• Metachronous CRC in the previous 5 years
• Patients with metastatic neoplastic disease at the time of diagnosis