Background: Patients with a history of colonic resection for cancer have an increased risk for the development of metachronous malignant lesions. However, there is a lack of data on the detection rates of premalignant lesions during colonoscopy surveillance in these patients, and the few existing studies have shown conflicting results.
Aims: To identify the risk factor of metachronous premalignant lesions after colon cancer surgery.
Methods: We retrospectively screened consecutive patients who had undergone colonic surgery to treat colon cancer at the Chungnam National University Hospital between September 2009 and April 2014. We measured polyp, adenoma, and advanced adenoma detection rates (PDR, ADR, AADR) from the second surveillance colonoscopy in patients with left-sided colectomy (LCR) or right-sided colectomy (RCR). Multivariate analysis was performed to adjust for other confounding factors.
Results: A total of 348 patients were enrolled (220 LCR patients and 128 RCR patients). The PDR, ADR, and AADR in patients in the LCR and RCR groups were 56.4, 43.6, and 11.8% and 35.9, 26.6, and 9.4%, respectively. PDR and ADR in the LCR group were significantly higher than those in the RCR group. A multivariate analysis showed that male sex, hypertension, body mass index higher than 25, and LCR (odds ratio 2.090; 95% confidence interval 1.011-4.317) were associated with adenoma recurrence.
Conclusions: The LCR group had a higher adenoma recurrence rate than the RCR group. Further studies are required to determine the optimal surveillance intervals according to the type of colonic resection.
Keywords: Adenoma recurrence rate; Colon cancer; Left-sided colectomy; Metachronous colorectal adenoma; Right-sided colectomy.