Does acromegaly really predispose to an increased prevalence of gastrointestinal tumours? 
The few published prospective studies suggest a strong association of colonic tumours with acromegaly, but include small numbers of patients.  In addition, the upper gastrointestinal tract of these patients has never been prospectively studied.  The aim of the present study was to investigate the incidence of gastric and colonic tumours in a large cohort of acromegalic patients.  Acromegalic patients consecutively admitted to an Endocrinology Department for diagnosis and follow-up, were submitted to gastroscopy and colonoscopy, to identify those harbouring gastrointestinal tumours.  Over a 5-year period, 54 out of 61 patients (78% with active disease) received colonoscopy and 42 out of 61 gastroscopy.  No patient had a past history of gastrointestinal malignancy.  All polypoid lesions found at colonoscopy and gastroscopy were separately recorded and biopsied.  No case of gastrointestinal cancer or gastric polyp was discovered.  Nineteen patients (35%) had 1-8 colonic polyps, including 5 (9.3%) with adenomas.  When compared to patients with a normal colon, those with polyps were significantly older (44.5 +/- 14.2 vs 52.1 +/- 10.9 years, P = 0.047), but the duration of acromegaly (10.8 +/- 8.4 vs 10.9 +/- 7.1 years, P = 0.9) and the number of patients with active disease were similar in both groups.  Acromegalic patients do not have an increased incidence of gastric tumours.  The observed significant variation in the prevalence of colonic adenomas (9-35%, P = 0.03) and cancer (0-15%, P = 0.017), between our patients and those of the published prospective studies with similar demographic characteristics, suggest that environmental and hereditary factors may be more important than the presence of acromegaly.