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 (CO) and adult-onset (AO) adult cancer survivors (CS).

Design: Retrospective comparison of CO-CS and AO-CS with CO idiopathic GHD (IGHD) and AO non-functioning pituitary adenoma patients (NFPA) and with the general population (standardized incidence ratio, SIR).

Setting: Data from KIMS study (Pfizer International Metabolic Database).

Patients: CO-CS (n=349; 50.4% females, mean baseline (MBL) IGF-I SDS -2.4) and IGHD (n=619; 35.7% females, MBL IGF-I SDS -3.4) as well as 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%CI, 5.9-16.9) and 6.5 (95%CI, 3.0-12.4) after exclusion of 7 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, 0.09-1.37). New malignant neoplasms occurred in three AO-CS (1.7%; SIR 1.1; 95%CI, 0.2-3.2) and 146 NFPA patients (153 cases, 6.0%, SIR 1.1; 95%CI, 0.9-1.2) after a median follow-up of 4.9 (1024 patient-years) and 5.6 years (15215 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 due to a prior malignancy.