Screening guidelines for colorectal cancer and polyps in patients with acromegaly.

Acromegaly is characterised by excessive levels of circulating growth hormone and its tissue mediator, IGF-1. Before effective treatment and lowering of growth hormone and IGF-1 the majority of patients with the disease died by the aged of 60 years. 2 This was largely attributable to diabetes mellitus and cardiovascular and cerebrovascular diseases. More recently, it has become apparent that patients with acromegaly have an increased prevalence of colorectal adenomas and cancer. It is probable that with more effective and aggressive treatment of both the underlying acromegaly and its metabolic and vascular complications, patients are now surviving long enough to develop malignant complications of the disease. That this increased risk might be related to serum growth hormone and/or IGF-1 levels is supported by recent epidemiological studies in the non-acromegalic population that have demonstrated an association between serum IGF-1 and the risk of colorectal cancer. 22