The purpose is to investigate whether polyps that look different at endoscopy, have formed via different mutations and have different risks of turning into cancer.

Laterally spreading tumours (LSTs), are polyps that have a lateral extension along the duodenal wall with minimal vertical growth. It has become evident over the last few years that rather than being a single entity requiring an accumulation of mutations, Duodenal and ampullary cancer is in fact a heterogenous disease forming via multiple distinct genetic pathways. It is therefore hypothesised that different polyp types have different genetic abnormalities, and potentially form via distinct genetic pathways, although this theory has not been widely examined.

This knowledge would be important in furthering our understanding of the development of cancer. There is accumulating evidence that genetic abnormalities may be a better predictor of cancer behaviour than histological grade. Additionally, guidelines for endoscopy surveillance are currently a one size fits all approach that do not reflect the genetic heterogeneity of the disease and the knowledge that only 5% of polyps progress to cancer. Genetic studies may assess future cancer risk to a person in polyps once removed and plan surveillance endoscopy frequency.

Inclusion Criteria:

• Intention to perform Endoscopic Mucosal Resection
• Adenoma equal to or greater than 20mm
• over 18 years of age
• Able to give informed consent to involvement in trial

Exclusion Criteria:

• Pregnancy
• Lactation: currently breastfeeding
• Taken clopidogrel within 7 days
• Taken warfarin within 5 days
• Had full therapeutic dose unfractionated heparin within 6 hours
• Had full therapeutic dose low molecular weight heparin (LMWH) within 12 hours
• Known clotting disorder

Patients with Duodenal and/or ampullary adenomas or cancers.