New Neoplasm During GH Replacement in Adults With Pituitary Deficiency Following Malignancy: A KIMS Analysis.

CONTEXT: Data on the association between growth hormone (GH) replacement in patients with GH deficiency (GHD) after malignancies and new neoplasms show conflicting results.

OBJECTIVE

To clarify the incidence of new malignant neoplasm in childhood-onset (CO) and adult-onset (AO) adult cancer survivors (CSs).

DESIGN

Retrospective comparison of CO-CS and AO-CS with CO idiopathic GHD (IGHD) and AO nonfunctioning pituitary adenoma (NFPA) patients and with the general population [standardized incidence ratio (SIR)].

SETTING

Data from the Pfizer International Metabolic Database study (KIMS).

PATIENTS: CO-CS [n = 349; 50.4% females; mean baseline (MBL) IGF-I standard deviation score (SDS), -2.4], IGHD (n = 619; 35.7% females; MBL IGF-I SDS, -3.4), AO-CS (n = 174; 42.5% females; MBL IGF-I SDS, -1.4), and NFPA (n = 2449; 38.1% females; MBL IGF-I SDS, -1.0).

MAIN OUTCOME MEASURES: SIRs of malignant neoplasms.

RESULTS

After a median follow-up of 5.9 years (2192 patient-years), 15 CO-CS (4.3%) had developed 16 new neoplasms. The SIR was 10.4 [95% confidence interval (CI), 5.9 to 16.9] and 6.5 (95% CI, 3.0 to 12.4) after exclusion of seven patients with skin cancers. In IGHD, three malignant neoplasms (0.5%) were observed after a median follow-up of 5.4 years (3908 patient-years; SIR, 0.47; 95% CI, 0.09 to 1.37). New malignant neoplasms occurred in three AO-CS (1.7%; SIR, 1.1; 95% CI, 0.2 to 3.2) and 146 NFPA patients (153 cases, 6.0%; SIR, 1.1; 95% CI, 0.9 to 1.2) after a median follow-up of 4.9 (1024 patient-years) and 5.6 years (15,215 patient-years).

CONCLUSIONS

The risk of second malignant neoplasms was increased in CO-CS but not in AO-CS, which illustrates the need to closely follow patients on GH replacement because of a prior malignancy.