Disturbances in calcium metabolism in childhood lymphoblastic leukemia, before and after chemotherapy

Nowadays with the current treatments, survival and life expectancy has increased in acute lymphoblastic leukemia (ALL) and hence researchers have focused more on long term quality of life in these patients. Some of the long-term problems of ALL patients include biochemical disturbances of vitamin D and minerals, reduction in mineral content of bone and pathological fractures due to osteoporosis. The aim of the current study is to establish and compare biochemical indices of mineral and bone metabolism in ALL patients before and after chemotherapy. The patient studied were children between one to ten years of age with ALL who visited the Department of Pediatric Oncology of Shiraz University of Medical Sciences in two consecutive years, and received the same chemotherapy regimens. Blood samples (to measure serum calcium, phosphorous, albumin and alkaline phosphatase) as well as urine samples (for calcium and creatinine) were collected immediately after the diagnosis and before the beginning of chemotherapy. Similar samples were also collected and tested four to eight months after the completion of induction of chemotherapy. Total number of 20 patients aged 8±2.4 years (50% boys and 50% girls) were studied. Average serum calcium level was 9 mg/dL before chemotherapy, and 9.4 mg/dL after it (p<0.05). Average difference of phosphorous (p>0.4) and Alkalin phosphatase (p>0.3) before and after chemotherapy were not significant. Sixty five percent of patients had hypercalciuria before chemotherapy but this proportion declined to 25%, four to eight months after completion of chemotherapy. It seems that disturbances of mineral and especially calcium metabolism are common in ALL patients. On the other hand, chemotherapy has not had a considerable effect in long term on indices of mineral and calcium metabolism and moreover it seems that with induction of chemotherapy, and hence, control of the disease process (after four to eight months) the above mentioned indices improve, i.e reduction of rate of hypercalciuria and significant increase in serum calcium so, the role of the disease process itself in the disturbances observed in mineral and bone metabolism is probably greater than the effect of chemotherapy.