Revisiting the Incidence of Hypercalcemia in Contemporary Diagnoses of Pediatric Patients With Solid Tumors.

Abstract

Background: Hypercalcemia is rarely observed in pediatric patients with cancer. However, rare cases of renal insufficiency and osteoporosis have been reported as severe consequences. Published literature focuses predominantly on hypercalcemia in pediatric hematologic malignancies, precluding causative associations with solid tumor disease histology or tumor characteristics.

Methods: In this retrospective cohort analysis, we identified 39 patients (aged < 21 years) diagnosed and hospitalized with a solid tumor and prolonged hypercalcemia over the span of 25 years at the Dana-Farber/Boston Children's Cancer and Blood Disorders Center. Hypercalcemia was defined as a sustained serum calcium of at least 11.5 mg/dL for more than 1 week. Disease characteristics, clinical symptoms, management, and outcome were analyzed.

Results: The median age for patients in this cohort was 2.3 years, and the majority of patients had a diagnosis of neuroblastoma, rhabdoid tumor, hepatoblastoma, or rhabdomyosarcoma. The 39 patients experienced 45 episodes of hypercalcemia, with a median peak serum calcium level (corrected for albumin) of 13.1 mg/dL. The median time from tumor diagnosis to a hypercalcemic episode was 5.4 months, suggesting that disease-directed therapy, tumor progression, or organ dysfunction may have contributed. Peak ionized calcium was not significantly associated with bone or bone marrow involvement, nor with metastatic disease.

Conclusions: This work describes the largest retrospective series of pediatric patients with solid tumors and hypercalcemia to date. Hypercalcemia was most frequently reported for a small subset of diseases, suggesting that disease histology, biology, and the intensive therapeutic interventions required to treat these diseases may be contributing to hypercalcemic risk.