A cross-sectional study to determine the prevalence of calcium metabolic disorder in malignant childhood cancers in patients admitted to the pediatric ward of Vali-Asr Hospital.

Calcium metabolic disorders, such as hypercalcemia is a potentially life-threatening disorder especially when coupled with an already compromised condition. The aim of this study was to determine the prevalence of metabolic calcium disorders in childhood cancers of patients admitted to the pediatric ward of Vali-Asr Hospital from the year 2001-2008. The study was carried out by reviewing hospital records of these patients from the hospital archives. Range of age was between 1 and 18 years. Inclusion criteria for the study population were the presence of total serum calcium evaluated at least once; and for the hypercalcemia subgroup, at least two occasions of elevated calcium levels. The prevalence of hypercalcemia and other metabolic abnormalities of phosphorus, alkaline phosphatase, urea and creatinine; the prevalence of parameters such as age, gender, type and duration of cancer were determined within these groups. Median of elevated calcium levels was also determined to classify hypercalcemia into moderate and severe hypercalcemia. Median was 11.7 mg/dl, therefore, severe hypercalcemia was ≥11.7 mg/dl and moderate hypercalcemia, a range between the upper limit of normal, 10.8 and 10.2 mg/dl for the child and adolescent respectively, and 11.7 mg/dl. Relationship between hypercalcemia and the other metabolic disorders and parameters were analyzed by the SPSS V.17 program. The population of study consisted of 148 cases. Hypercalcemia was found in 8 (5.4%) patients. Half of the cases were associated with severe hypercalcemia and acute lymphoblastic leukemia (ALL). Out of 148 cases, there were 92 (62%) boys and 56 (38%) girls. Mean and median ages were 10.9 and 11 years respectively. Mean duration of cancer was 12.8 and median 6 months. There were 57 (38.5%) cases of leukemia and 91 (61.5%) cases of solid tumors. The most common cancers were ALL, 44 cases (29.7%) followed by brain tumors, 19 cases (12.8%); non-Hodgkin's lymphoma, 16 cases (10.8%); 13 cases of acute myeloid leukemia (AML) (8.8%); 13 cases of Ewing sarcoma (8.8%); osteosarcoma, 9 cases (6.1%); Hodgkin's lymphoma, 6 cases (4.1%); others, 19.1%. There was no significant difference between hypercalcemia and the metabolic disorders and parameters. Metabolic calcium disorder, especially hypercalcemia, is not a rare finding in pediatric cancers. ALL, the commonest pediatric cancer, is most often associated with this disorder.