Neoplasms Colorectal

Solid tumours are abnormal lumps of tissue that can occur in different parts of the body. The tumours involved in this study have specific genetic characteristics that can make them more aggressive and challenging to treat. The study will test whether GSK5460025 alone or in combination (potential combinations may be included in future amendments to the protocol) with other anti-cancer agents can decrease tumor size, is safe, well-tolerated, and how the drug is processed in the body over time.

EMR and ESD are both effective and safe and are associated with a very low risk of procedure related mortality when performed for colorectal laterally spreading lesions (LSL). Some kind of LSLs have a low risk of submucosal invasive carcinoma (SMIC) or these foci are found in well demarcated areas of the tumor. This is the case of the non-granular flat elevated (LSN-NG-FE) and the LSLs-G mixed subtypes. The investigators aim to assess if piecemeal EMR (the older technique) for LSLs-G mixed type \> 30 mm and LSLs-NG FE type \> 20 mm is not inferior to ESD (the new treatment) for the need of additional surgery in the mid-term.