Patient and pathological predictors of management strategy for malignant polyps following polypectomy: a systematic review and meta-analysis

Abstract

Purpose Malignant polyps present a treatment dilemma for clinicians and patients. This meta-analysis sought to identify the factors that predicted the management strategy for patients diagnosed with a malignant polyp. Methods A literature search was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Cochrane Collaboration prognostic studies guidelines. Reports from 1985 onwards were included, data on patient and pathological factors were extracted and random effects meta-analysis models were used. Results Fifteen studies were included. Seven studies evaluated lymphovascular invasion (LVI). The odds of surgery were significantly higher in malignant polyps with LVI (OR 2.20, 95% CI 1.36–3.55). Ten studies revealed the odds of surgery were significantly higher with positive polypectomy margins (OR 8.09, 95% CI 4.88–13.40). Tumour differentiation was compared in eight studies. There were significantly lower odds of surgery in malignant polyps with well/moderate differentiation compared with poor differentiation (OR 0.31, 95% CI 0.21–0.46). There were non-significant trends favouring surgical resection in younger patients, males and Haggitt 4/Kikuchi Sm3 lesions. There was considerable heterogeneity in the meta-analyses for the variables age, gender, polyp morphology and Haggitt/Kikuchi level (I2 > 75%). Conclusion This meta-analysis has demonstrated that LVI, positive polypectomy resection margins, and poor tumour differentiation significantly predict malignant polypectomy patients who underwent subsequent surgery. Age and gender were important factors predicting management, but not consistently across studies, whilst polyp morphology and Haggitt/Kikuchi levels did not significantly predict the management strategy. Further research may assist in understanding the management preferences.

A population‐based study of the management of rectal malignant polyps and the use of trans‐anal surgery

“…In reviewing the literature for the comparison of management strategies of colorectal polyps, a series of meta‐analyses documented that LVI, poor differentiation and close or involved margins were significant predictors of resection. 2 When reviewing the articles included in those meta‐analyses, only five studies had mentioned the inclusion of TAR techniques in their review. In two of these studies, TAR techniques were combined with polypectomy as the overall management strategy.…”

“…However, those that invade beyond submucosa are no longer defined as malignant polyps. 1,2 Rectal malignant polyps can be managed with three techniquespolypectomy alone, rectal resection or with a trans-anal resection (TAR). 3 There are several methods to perform a TAR of a rectal malignant polyp.…”

“…Any endoscopically complete resection of a polyp containing carcinoma invading through muscularis mucosae is considered a malignant polyp. However, those that invade beyond submucosa are no longer defined as malignant polyps 1,2 …”

“…Guidelines have been developed to assist clinicians in the clinical decision making as to when to recommend colorectal resection for malignant colorectal polyps 7 . There have been few population wide analyses of the management of colorectal malignant polyps, and few have specifically investigated the role of trans‐anal excisions as part of the management strategy 2,8,9 . In Queensland, Australia, the reporting of cancer data to the Queensland Cancer Registry (QCR) is mandated by law.…”

“… 7 There have been few population wide analyses of the management of colorectal malignant polyps, and few have specifically investigated the role of trans‐anal excisions as part of the management strategy. 2 , 8 , 9 In Queensland, Australia, the reporting of cancer data to the Queensland Cancer Registry (QCR) is mandated by law. This data is linked with over 60 other population level information sources, to form the Queensland Oncology Repository (QOR).…”