High levels of calcium in blood, known as hypercalcaemia, can be used as an early sign of certain types of cancer, claim scientists. This can be diagnosed using a simple blood test.
Hypercalcaemia is the most common metabolic disorder associated with cancer, occurring in 10 to 20 percent of people with cancer. While its connection to cancer is well known, this study has, for the first time, shown that often it can predate the diagnosis of cancer in primary care.
The research by universities of Bristol and Exeter analysed the electronic records of 54,000 patients who had elevated levels of calcium and looked at how many of them went on to receive a cancer diagnosis.
Analysis of the data found that in men, even mild hypercalcaemia (2.6-2.8mmoll-1) conferred a risk of cancer in one year of 11.5 percent. If the calcium was above 2.8 mmoll-1, the risk increased to 28 percent. In women, the risks were much less, with the corresponding figures being 4.1 percent and 8.7 percent.
In men, 81 percent of the cancer associated with hypercalcaemia was caused by lung, prostate, myeloma, colorectal and other haematological cancers. In women, cancer was much less common.
Lead researcher Dr Fergus Hamilton said the reason behind the gender difference might have been that women were much more likely to have hyperparathyroidism, another cause of hypercalcaemia. Men rarely had the condition, hence their hypercalcaemia was more likely to be due to cancer.
The study is published in the British Journal of Cancer.