GPs are being urged to investigate for cancer in hypercalcaemic men, after a study revealed a ‘striking’ gender disparity in the risk of malignancy.
Men with even mild hypercalcaemia faced an 11.5% elevated risk of developing cancer over one year compared to healthy controls with normal calcium levels, the UK primary care–based study found.
In women, by contrast, mild hypercalcaemia conferred just a 4.1% increased risk of cancer.
Lung, prostate, myeloma, colorectal and other haematological malignancies were the most common cancers in men with elevated calcium, according to the research, published in the British Journal of Cancer.
With over 54,000 participants, it is claimed as the largest study to date into the prognostic significance of hypercalcaemia in general practice.
“This study shows for the first time the difference in risk between male and female patients who have hypercalcaemia in primary care,” said lead author Dr Gus Hamilton, of the University of Bristol’s Centre for Academic Primary Care.
“This information should really help GPs in their decision making. In older men with any level of raised calcium the risk of cancer is reasonable and investigation would certainly be warranted. However, in women with relatively modest hypercalcaemia the risk is much less significant, and GPs might consider other potential causes first.”
Dr Hamilton and colleagues assessed the incidence of cancer within one year of a calcium result in 54,267 adults aged over 40 in the General Practice Research Database.
Hypercalcaemia – defined as any result above 2.6 mmol/l – was present in 1674 participants; the remainder served as controls.
The gender disparity grew even more pronounced with increasing serum calcium levels: men with moderate (2.8-2.99 mmol/l) and severe (above 3.0 mmol/l) hypercalcaemia were 27.9% and 50% respectively more likely than controls to develop cancer. In women the corresponding figures were 8.7% and 16.7%.
Dr Hamilton and colleagues cautioned that the absolute risk of being diagnosed with cancer following an elevated calcium score remained low, especially with milder cases of hypercalcaemia.