O-053. Acromegaly, colonic polyps and carcinoma

Objectives: To clarify whether patients with acromegaly are at increased risk of developing colorectal carcinoma. Methods: We performed prospective colonoscopic evaluation of the prevalence of colonic neoplasms, premalignant tubular adenomas and benign hyperplastic colonic polyps in 129 patients with acromegaly. Results: 63 patients had at least one lesion: 73% were in the descending colon or rectum, 9% in the transverse and 16% in the ascending colon. Adenocarcinoma was present in 6 patients (5%), only two of whom had relevant symptoms. Compared with age-adjusted general population rates of colorectal cancer, there is a relative risk of 92.6 (95% CI 34-201; p<0.0001). One or more tubular adenomas was found in 34 patients (26%) and this prevalence was age-dependent, occurring in 39% of patients aged 70 years or over. Comparing the prevalence of left-sided colonic adenomas with that in an asymptomatic population, there is a significantly higher prevalence amongst the patients aged over 49 years with a relative risk of 3.8-4.7 (p<0.01-0.001). Patients with acromegaly who had an adenoma were significantly older than unaffected patients (61.9 vs 54.1 yrs; p<0.001). There was no significant relationship to the severity or duration of acromegaly, nor to treatment with the somatostatin analogue, octreotide or the dopamine agonist, bromocriptine, nor radiotherapy. Conclusions: Patients with acromegaly have an increased risk of developing colorectal cancer and a significantly higher prevalence of tubulovillous adenomas compared with normal subjects.