Diabetes Mellitus and Age are Risk Factors of Interval Colon Cancer: A Case-Control Study

Interval colorectal cancer (CRC) is largely related to a poor endoscopic performance or different biology in the development of the polyp. However, patient- related factors were less investigated for their association with interval cancer. We thus evaluated tumor and patient characteristics as predictors of interval cancer in a population from Israel. Methods: In this retrospective study, patients that were diagnosed with colon cancer in our institution and had 2 colonoscopies were included. Demographic parameters and tumor characteristics were compared between 84 cases with interval cancer, occurring 1-10 years after a negative colonoscopy, and 983 patients with primary CRC. In addition, patient-related features, including diabetes and diverticulosis, were compared between 51 patients with interval cancer after negative colonoscopy and 255 controls with no cancer and a previous negative colonoscopy. Rsults: Compared to positive controls with primary cancer, patients with interval cancer were older (age 71.3 vs. 67.6, p = 0.003), had proximal tumor location (57 vs. 34%, p > 0.001) and non-advanced (0-2) tumor staging (78.5 vs. 64.8%, p = 0.014). Compared with negative healthy controls, cases with interval cancer had only higher prevalence of diabetes (31 vs. 15%, p = 0.002). No significant differences were seen between patients with interval cancer occurring > 3 years and after 3-10 years. Conclusions: Patients with Interval cancer tend to be older and have diabetes. These patient groups should be more carefully or more frequently screened for pre-malignant lesions.