Canine lymphosarcoma: A model for study of the hypercalcemia of cancer

Lymphosarcoma of domestic dogs is often accompanied by hypercalcemia. We have carried out studies to determine the usefulness of this common canine neoplasm as a model for paraneoplastic hypercalcemia. The study population consisted of 27 healthy control dogs, 13 with hypercalcemic lymphosarcoma, and 28 normocalcemic dogs with lymphosarcoma. Studies included measurement of circulating calcium, phosphorus, creatinine, immunoreactive parathyroid hormone (iPTH) and prostaglandin E2 (iPGE2) concentrations, and determination of in vitro bone-resorbing activity in supernatant culture media from normal and neoplastic lymphoid tissue. Hypercalcemia was severe in the affected group (mean ± SE, 14.9±0.5 mg/dl, normals 10.1±0.1 mg/dl) and associated with decreased renal function (serum creatinine 2.0±0.4 mg/dl, normal 0.8±0.1 mg/dl,P