The risk of cancer in primary care patients with hypercalcaemia: a cohort study using electronic records

Background:The risk of cancer with hypercalcaemia in primary care is unknown.Methods:This was a cohort study using calcium results in patients aged > 40 years in a primary care electronic data set. Diagnoses of cancer in the following year were identified.Results:Participants (54 267) had calcium results: 1674 (3%) were >2.6 mmol l(-1). Hypercalcaemia was strongly associated with cancer, especially in males: OR 2.92, 95% CI 2.17-3.93, P=<0.001; positive predictive value (PPV) 11.5%; females: OR 1.86, 95% CI 1.39-2.50, P<0.001: PPV 4.1%.Conclusions:Hypercalcaemia is strongly associated with cancer in primary care, with men at most risk, despite hypercalcaemia being more common in women.British Journal of Cancer advance online publication, 5 August 2014; doi:10.1038/bjc.2014.433 www.bjcancer.com.