Calcium blood test could help GPs spot cancer earlier A test for high levels of calcium in the blood could give GPs an early warning that a patient has cancer, research suggests. by Stephen Robinson Sign in to continue Sign In Email address Password Stay signed in Trouble signing in? Reset password: Click here Need help? Email us Register FREE Limited free articles a month Free email bulletins Register Now Register Now Take a 30-day trial Join MIMS now and pay nothing for the first 30 days Join GPOnline now and pay nothing for the first 30 days Sign Up Sign Up