Long-term cancer risk in acromegaly: a population-based cohort study with 44 years of follow-up

Cancer risk in acromegaly remains debated, with studies showing both increased and similar risk compared to the background population. We conducted a nationwide cohort study examining the risk of cancer and benign colorectal lesions in acromegaly patients.

The study included acromegaly patients diagnosed in Denmark (1977-2021, n = 809, median follow-up 12.2 [IQR: 5.6-21.7] years (range: 0.04-44.0) and controls matched on sex and birth year (n = 80 900). All diagnoses of acromegaly were biochemically validated. We investigated the occurrence of cancer diagnoses, benign colorectal lesions, performance of colonoscopies and mortality with time-to-event statistics and logistic regression.

Overall cancer risk was not clearly increased (IRR: 1.10 [0.93;1.30], P = .27), but patients with acromegaly had an increased risk of colorectal cancer (IRR: 1.78 [1.22;2.60], P < .01) and thyroid cancer (IRR: 3.68 [1.16;11.66], P = .03). Colorectal cancers were more often localized (IRR: 2.00 [1.21;3.30], P = .007) as compared to controls, and the use of endoscopic colorectal procedures was increased (IRR: 2.85 [2.54;3.19], P < .01). The incidence of benign colorectal lesions was elevated in acromegaly patients (IRR: 2.32 [1.96;2.76], P < .01) and dominated by tubular adenomas (43.6%) and hyperplastic polyps (33.2%). Fecal immunochemical test (FIT) screening and clinical suspicion guided the use of colonoscopies, rather than systematic colonoscopy screening. All-cause mortality was elevated in acromegaly (IRR: 1.18 [1.02; 1.36], P = .03), but cancer-specific mortality was not (IRR: 0.95 [0.72;1.25], P = .72).

Acromegaly carries an increased risk of colorectal cancer, but neither overall cancer risk nor cancer-specific mortality is increased.