Problem addressed, background and strategic significance
Screening for bowel cancer saves lives partly by detecting cancers at an early stage. The very earliest cancers occur as microscopic tumours in polyps removed during colonoscopy (polyp cancer). These were rare before screening but make up at least 10% of screen-detected cancers. We have only limited information on how best to manage patients with polyp cancer. There is urgent need to identify which individuals require surgical removal of colon and which can be managed conservatively. We propose to use the Scottish screening patients with polyp cancer to answer this question
Pathological examination of the polyp cancer is key to determining prognosis and management. We have acquired full clinical and outcome data on 485 polyp cancers detected in screening (larger than any published series). We propose to retrieve the pathology slides from the original samples and have them reviewed by a panel of 4 experts who will look for evidence that the cancer has been completely removed, for cancer cell invasion into blood vessels, for tumour differentiation (a marker of aggressive behaviour). The size of invasive tumour will also be measured. These parameters will be entered on our clinical database and related to existing data on outcomes in patients treated conservatively and also those having subsequent surgery.
Hoped for results of this research
The size and completeness of our data should provide the best data yet to guide management of polyp cancer of the colon
How will this project help build on the Delphi question and what further plans are proposed for future development?
We will be able to directly address the issue of when surgical management is justified and construct an evidence-based guideline to identify best management and endoscopic surveillance.