Is the routine measurement of ionized calcium worthwhile in patients with cancer?

Abstract

Summary:This study was undertaken to analyse the relationship between total calcium (TCa) and ionized calcium (ICa) in patients with cancer, and to assess the clinical value of routine measurements of ICa in these patients. Serum TCa, ICa, albumin, proteins and creatinine were measured in 188 adult patients with solid malignant tumours. Most of them were out-patients, the Karnofsky score being 80 or above in 67%. The correlation coefficient between ICa and TCa was 0.85 (P < 0.001) and did not improve after correcting TCa for protein concentration with several published formulae. Although TCa measurements had a global diagnostic accuracy (percent of patients correctly classified) of 90%, they failed to identify a substantial proportion of patients with increased levels of ICa (57% for uncorrected TCa, and 27-57% for protein-corrected TCa). However, the finding of slightly increased ICa levels did not seem to predict the development of frank hypercalcaemia and did not impair the prognosis. According to these results, the routine measurement of ICa in unselected patients with cancer has no clinical usefulness.

Incidence of hypocalcemia and hypercalcemia in hospitalized patients: Is it changing?

“…Since about 80% of the protein-bound calcium is associated with albumin, albumin levels could influence calcemia. Thus we considered only patients whose calcium serum concentration was corrected taking in account albumin levels [11] , [12] , [13] .…”

A challenging diagnosis of rare co-existent multiple myeloma and prostate adenocarcinoma: a systematic review of case reports

“…Riancho et al reported an incidence of 5-13% in patients with solid tumours and bone metastases 56 . The difference depends on the calculation of corrected total calcium value as serum albumin concentrations are reduced in cancer patients 57 .…”

Total Calcium and Ionized Calcium (pH = 7.4) Tests Are Equal When Screening Patients for Hypercalcemia at Admission in the Emergency Department: A Retrospective Descriptive Study

“…However, it has been found that patients with solid tumors and mildly increased calcium usually did not develop frank HC at followup and that the HC did not seem to influence on the prognosis. Therefore, it was suggested, that CaI should not be measured routinely in these patients [16]. Yet, in cases of multiple myeloma, which affects the bones, we think that CaI should be preferred [17].…”

“…CaI should be considered in a number of clinical situations such as calcium metabolic diseases [8,14], CKD [15], low albumin, and cancer [16] including multiple myeloma [17]. CaI has been shown to be a more sensitive indicator of PHPT in cases of calcium metabolic disease and more linearly associated with adenoma size in a study with 269 patients who had all undergone PTX because of PHPT [14].…”