Evaluation of the risk for metachronous colorectal neoplasms following intestinal polypectomy: a clinical, endoscopic and pathological study

Surveillance programs are recommended for patients with previous intestinal polypectomy because of the high rate of adenomatous recurrences and risk of subsequent colorectal cancer. The parameters to identify patients at higher risk and the length and schedules of follow-up have not yet been established. We considered some clinical, endoscopic and pathological parameters in order to assess the probability of developing new colorectal neoplasms and eventually to schedule proper surveillance programs.

Patients with removed adenomas were enrolled into a clinico-endoscopic follow-up, comprehensive of two colonoscopies the first at 1 year and the second at 3 years. We evaluated the risk of new neoplasms dividing the patients into four groups according to the number and size of the adenomas removed and the parameters considered.

Of 164 patients enrolled 156 completed the study. We had an overall 21.3% of adenomatous recurrences at 1 year and 12.8% at 3 years. Most of the adenomas removed were tubular and small in size (< 1 cm). The percentage of patients who had adenomas with advanced pathological features was 1.82% at 1 year and 0.64% at 3 years. The increase in number and size of the adenomas removed on the initial colonoscopic examination was the only one parameter statistically significant, X(2)1 (trend) 5.11; p<0.05 at the first follow-up and X(2)1 (trend) 4.87; p<0.05 at the second follow-up.

Patients with previous single adenoma showed few recurrences of extremely benign histological features. Since they do not require short-term endoscopic examination, it would be reasonable to defer the next colonoscopy for at least another 5 years. During follow-up, patients with multiple polyps had adenomas with advanced pathological features so it was useful to follow-up at 1 year. The tendency for advanced pathological features of removed polyps was not seen at 3 years, suggesting the importance of long-term follow-up, but with longer intervals.