PTU-068 Long-term follow-up data for a series of polyp cancers resected during bowel cancer screening colonoscopy

Introduction Since commencement of national bowel cancer screening programme (BCSP), malignant colorectal polyps (AKA polyp cancers) – adenomas resected with a focus of cancer – represent 9.8% of detected colorectal cancers (CRC). Optimal management remains unclear. We previously presented a case series of 48 patients who had a polyp cancer managed by polypectomy alone, suggesting that those staged Haggitt 1 and 2 without adverse prognostic features are safe to be managed non-surgically, as can those with Haggitt 3 if confident of adequate resection margin. We revisit this cohort to assess long-term outcomes. Methods 48 patients with polyp cancers resected by polypectomy alone (04/2008 – 11/2011) in Leicestershire and Northamptonshire BCSP have had their outcomes reviewed (12/2017). Results Demographic data Median age=66 Males/Females=33 (68.75%)/15 Location Rectum=5 (10.4%)/Sigmoid=41 (85.4%)/Descending colon=2 (4.2%) Haggitt 1 Two patients with sigmoid Haggitt 1 polyp cancers have died. One with right sided CRC after 2 years 2 months, the other with sigmoid CRC after 7 years 10 months – both metachronous lesions. Another patient died of lung cancer after 6 years 3 months. Haggitt 2 A patient died of dementia after 5 years 8 months, another died of Mesothelioma after 2 years 4 months. Haggitt 3 A patient died of metachronous sigmoid CRC after 5 years, another died of pneumonia after 7 years 8 months. Other polyp cancers Of 13 other polyp cancers, 5 were pedunculated but not assigned Haggitt stage due to incomplete excision or invasive cancer – one patient has died with liver metastases (recurrent CRC). There were 8 sessile polyp cancers with 1 recurrent sigmoid CRC and 1 COPD death – too small a group to draw meaningful conclusions. Conclusion There were 26 patients with Haggitt 1 or 2 polyp cancers without adverse prognostic features managed by polypectomy alone. Mean follow-up of 7 years 3 months has not identified recurrence (by way of metastases), however two patients developed metachronous CRC. This suggests that endoscopic polypectomy is curative. 9 patients with Haggitt 3 polyp cancers have 7 years 9 months mean follow-up (one developed metachronous CRC). Patients staged Haggitt 3 – where there is confidence of adequate resection margin – need to have a discussion around the option of surgery (with its associated risks) versus conservative management. There are increased risks of adverse outcomes (lymph node metastasis/recurrence) from Haggitt 4 and sessile Kikuchi polyp cancers due to invasion into submucosa, surgery needs to be considered to reduce risk of recurrence.