P362 Systematic review: Oncological outcomes of patients with Inflammatory Bowel Disease undergoing segmental colonic resections for colorectal cancer and dysplasia

Shamsiddinova, A.(1,2)*;Deputy, M.(1);Worley, G.(1);Rao, C.(2,3);Dean, H.(1);Thomas-Gibson, S.(4,5);Faiz, O.(1,2);

(1)St Mark's Hospital, Colorectal Surgery, London, United Kingdom;(2)Imperial College London, Department of Surgery and Cancer, London, United Kingdom;(3)North Cumbria Integrated Care NHS Foundation Trust, Colorectal Surgery, Carlisle, United Kingdom;(4)St Mark's Hospital, Gastroenterology, London, United Kingdom;(5)Imperial College London, Department of Metabolism Digestion and Reproduction, London, United Kingdom;

Background

Current international guidelines recommend that patients with inflammatory bowel disease (IBD) diagnosed with high grade dysplasia (HGD), or colorectal cancer undergo a proctocolectomy, and that proctocolectomy is considered within a shared decision-making framework with the patient in cases of low grade (LGD) or indeterminate (IND) dysplasia.  However, segmental colectomy (surgical resection leaving remaining colon or rectum) is considered by some as a valid alternative, with less physiological stress, stoma avoidance and thus acceptability to patients. This systematic review aims to assess oncological and post-operative outcomes in studies reporting on segmental colectomy or proctocolectomy for patients with IBD and colonic or rectal dysplasia and cancer.

Methods

This systematic review was prospectively registered with PROSPERO (CRD42021292891) and carried out in line with the PRISMA guidelines. Studies published between 1990 and 2022 reporting on oncological and surgical outcomes of adult patients undergoing segmental resection and/or proctocolectomy that included at least three cases of neoplasia were included. Descriptive statistics were used in the context of significant heterogeneity. A meta-analysis was performed for outcomes with at least three results.

Results

The search returned 2178 results, and after screening 12 studies were included in the final analysis. A total 12,701 patients were included reporting on outcomes of 10,386 segmental resections and 2,315 proctocolectomies. The pooled incidence of missed synchronous cancers (i.e. identified in remaining colon or rectum within 6 months of surgery) in the segmental resection group was 1.4%, and dysplasia 0.5%; metachronous cancer recurrence was 1.4% (1.1% in subtotal colectomy, 11.8% in any other segmental resection), and dysplasia recurrence 5.3% (4.7% in subtotal colectomy, 7.5% in any other segmental). Average time to recurrence for metachronous cancer was 6.5 years. Recurrence of metastatic cancer was 0.2% for proctocolectomy, and 0.1% for segmental resection (OR 1.28, 95% CI 0.19 - 8.65, p =ns).

Conclusion

Segmental colectomy does not disadvantage against metastatic cancer recurrence. The incidence of missed synchronous lesions is low. There is increased metachronous cancer risk, however this is mitigated by subtotal colectomy. These results may help to counsel patients regarding the risks and benefits of segmental resection for IBD-related dysplasia and cancer. The risk of metachronous cancer after segmental resection reiterates the need for enhanced high quality post-operative surveillance. The paucity of data in this field is also demonstrated here by the high inter-study heterogeneity, highlighting the need for prospective studies.