Patients with hypercalcaemia, a common metabolic change associated with cancer, were more likely to be diagnosed with certain malignancies within the next year, the study found.
Researchers from the Universities of Bristol and Exeter analysed data from the medical records of 54,000 patients aged over 40, around 3% of whom had elevated calcium levels. The findings are published in the British Journal of Cancer.
Mild hypercalcaemia (2.6-2.8mmol/L) in men was linked to an 11.5% risk of cancer in the following year; nearly three times higher than men without elevated levels.
For calcium levels above 2.8mmol/L, one-year risk increased to 28%, and to 50% when levels rose above 3mmol/L. In contrast, the risks in women were only 4.1%, 8.7% and 16.7% respectively.
Men were most at risk despite hypercalcaemia being more common in women.
Among men, 81% of cancers linked to hypercalcaemia were lung, prostate, myeloma, colorectal and other haematological cancers.
Researchers said a simple blood test could help GPs identify which patients require further investigation.
Lead author Dr Fergus Hamilton at the University of Bristol said: 'All previous studies on hypercalcaemia and cancer had been carried out with patients who had already been diagnosed with cancer - hypercalcaemia was seen as a late effect of the cancer.
'We wanted to look at the issue from a different perspective and find out if high calcium levels in blood could be used as an early indicator of cancer and therefore in the diagnosis of cancer.'
Dr Hamilton added: 'We were surprised by the gender difference. There are a number of possible explanations for this but we think it might be because women are much more likely to have hyperparathyroidism, another cause of hypercalcaemia. Men rarely get this condition, so their hypercalcaemia is more likely to be due to cancer.'
Hypercalcaemia is the most common metabolic disorder associated with cancer, occurring in 10% to 20% of people with cancer.