In a Dutch trial reported in the Journal of Clinical Oncology, Simone D. Hennink, MD, of Leiden University Medical Center in Leiden, the Netherlands, and colleagues found that a 6-year colonoscopic surveillance interval is sufficient for many individuals with familial colorectal cancer.1 However, in those with advanced adenomatous polyps at baseline, surveillance every 3 years may be warranted.
Hans F.A. Vasen, MD, of Leiden University Medical Center, is the corresponding author for the Journal of Clinical Oncology article.
In the study, 528 individuals aged 45 to 65 years with one first-degree relative with colorectal cancer aged < 50 years or two first-degree relatives with colorectal cancer and who had 0 to 2 adenomas at baseline were randomly assigned to colonoscopy at 6 years (n = 262) or at 3 and 6 years (n = 266). The primary outcome measure was advanced adenomatous polyps. Adenomas were present at baseline in 18% and 17% of patients, and advanced adenomatous polyps were present in 1.9% and 5.6%.
The proportion of individuals with advanced adenomatous polyps was 6.9% at 6 years in the 6-year group vs 3.5% at 3 years (crude odds ratio [OR] = 2.0, 95% confidence interval [CI] = 0.89–4.7) and 3.4% at 6 years (crude OR = 2.1, 95% CI = 0.89–5.0). Only one case of colorectal cancer was found, at 3-year evaluation in a patient in the 3-year group.
Only the presence of advanced adenomatous polyps at baseline was a significant predictor for the presence of advanced adenomatous polyps at first follow-up. After correction for this factor, surveillance at 6 years in the 6-year group was associated with significantly increased risk for advanced adenomatous polyps vs surveillance at 3 years (adjusted OR = 2.44, P = .044) and at 6 years (adjusted OR = 2.61, P = .038) in the 3-year group.
The investigators concluded: “In view of the relatively low rate of advanced adenomatous polyps at 6 years and the absence of colorectal cancer in group A, we consider a 6-year surveillance interval appropriate. A surveillance interval of 3 years might be considered in patients with advanced adenomatous polyps and patients with > three adenomas.” ■
Disclosure: The study was supported by a grant from the Netherlands Organisation for Health Research and Development.