Poster Presentation Clinical Oncology Society of Australia 2014 Annual Scientific Meeting

Risk factors for metachronous colorectal neoplasia: a systematic review and meta-analysis (#429)

Harindra Jayasekara 1 , Jeanette C. Reece 1 , Daniel D. Buchanan 1 2 , Susan Parry 3 , Mark A. Jenkins 1 , Aung Ko Win 1
  1. Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Carlton, VIC, Australia
  2. Genetic Epidemiology Laboratory, Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia
  3. New Zealand Familial Gastrointestinal Cancer Service, Auckland, New Zealand

Aims: An individual’s risk of developing a metachronous colorectal neoplasm has implications on the extent of colonic resection for the initial tumour and the intensity of colonoscopy surveillance. Our aim was to conduct a systematic review and meta-analysis of risk factors for metachronous colorectal neoplasia.       

Methods:  An electronic database search was conducted using PUBMED and Web of Science for potentially relevant original publications reporting an association between metachronous colorectal neoplasia and its predictors, published through May 2014. We used broad search criteria and keywords: “colorectal neoplasms”, “metachronous”, “second primary”, “risk factors”. A metachronous neoplasm was defined as a new (primary) adenoma or carcinoma of the colon or rectum occurring at least 6 months after a previous diagnosis of colorectal carcinoma. Pooled relative risks were derived for selected risk factors using DerSimonian-Laird random effects models. Study heterogeneity was assessed by the I2 statistic. Publication bias was assessed using Egger’s regression test.

Results: One-hundred-and-eighty-seven full-text articles were selected after excluding the others on the basis of their titles and abstracts. Of these, 80 were excluded because they did not examine an association between metachronous colorectal cancer and its risk factors, 11 as they were reviews, conference abstracts or meta-analyses, and a further 4 that were duplicate analyses of the same study population. A manual search of reference lists captured one further study, leaving us with 93 unique articles for review at this stage. These were predominantly cohort studies, with most conducted in Europe followed by North America and Asia. To date, extraction of data including risk factors assessed, measures of association and covariates included in analysis, has been completed.    

Conclusions: So far, we have identified studies that have reported an association between metachronous colorectal neoplasia and its risk factors. They will be reviewed systematically and summarized, next.