Prevalence of hypercalcemia of malignancy among cancer patients in the UK: analysis of the Clinical Practice Research Datalink database

Abstract Background The reported proportion of cancer patients who experience hypercalcemia of malignancy (HCM) ranges between 3% and 30%. HCM can be observed with any type of tumor and occurs most commonly in lung cancer, breast cancer and multiple myeloma. While HCM is a potentially fatal condition, the prevalence of HCM is not well defined. Methods Using the United Kingdom Clinical Practice Research Datalink, we identified adult cancer patients with recorded corrected serum calcium (CSC). Hypercalcemic patients (CSC ≥10.8 mg/dL) were classified into 4 CSC levels. We estimated annual prevalence of HCM overall, stratified by cancer type, and in patients with stage IV cancer. Results Among 37,442 cancer patients in 2003–2012 the prevalence of grade 1 HCM increased from 0.13% to 0.45% and the prevalence of HCM overall (grade 1 or higher) increased from 0.20% to 0.67% over the study period. Prevalence estimates varied across cancer type and were highest for lung cancer, multiple myeloma and patients with stage IV cancer. Conclusion We provide the first systematic analysis using a UK population-based data source to estimate number of cancer patients affected with HCM by grade. The increase in HCM prevalence over the 10-year study period is likely due to the increased recording of laboratory values, particularly comparing more recent data to 2003. Our findings suggest that HCM in general is not a common condition.