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

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.