The Incidence of Cancer Among Acromegaly Patients: Results From the German Acromegaly Registry.

ABSTRACT

CONTEXT Acromegaly is a rare disease characterized by high serum levels of GH and IGF-1. Animal studies have demonstrated links between these hormones and cancer, but data regarding cancer incidence among acromegaly patients are inconsistent. Moreover, therapy options have changed considerably since many of the aforementioned data were collected. OBJECTIVE: The objective was to determine whether the overall and site-specific incidence of cancer is comparable to that of the general population. DESIGN AND SETTING: Data from the German Acromegaly Registry for 446 patients (6656 person-years from diagnosis) treated in seven specialized endocrine centers were analyzed. MAIN OUTCOME MEASURE: Standard incidence ratios (SIRs) were calculated as compared to the general population. RESULTS: Overall cancer incidence was slightly but not significantly lower than in the general population (SIR, 0.75; 95% confidence interval, 0.55 to 1.00; P = .051) and was not significantly higher for colorectal, breast, thyroid, prostate, and lung cancers. The SIRs of those with GH in the ranges <1, 1-2.5, and ≥ 2.5 ng/mL were 0.75, 0.44, and 0.92, respectively (P = .94). There was not a significant dependence on normal vs elevated IGF-1 (P = .87), radiation therapy (P = .45), disease duration (P = .96), age at diagnosis (P = .15), or during a period of high GH and IGF-1 from 8 years before to 2 years after diagnosis of acromegaly (P = .41). CONCLUSIONS: Cancer screening strategies need to take incidence into account, which does not seem to be substantially higher in treated acromegaly patients than in the general population for any site of cancer.