In a speech to the Labour Party conference in Brighton, Mr Brown was expected to say on Tuesday that helping GPs make an earlier diagnosis of cancer will save up to 10,000 lives every year.
Under the plans, GPs will be able to refer patients directly for diagnostic tests to confirm or exclude a range of cancers.
Initially GPs will focus on some of the biggest killers, such as lung and colorectal cancer, with a commitment to extend this to all cancers within five years.
RCGP chairman Professor Steve Field said: 'The two-week referral time for patients where there is a high suspicion of cancer has made a major difference to patients and their GPs.
'But GPs would welcome the opportunity to refer patients directly for diagnostics such as MRI and CT scans, ultrasound and flexible sigmoidoscopy without having to refer to a specialist first.
'Giving GPs easier access is a superb idea. Even if the results of the tests are normal, it will be of great benefit and reassure patients. It will also help us to pick up on very early symptoms.'
Harpal Kumar, Cancer Research UK chief executive, added: 'Increased investment to give GPs much faster access to diagnostic tests would be a vital step towards fixing this country's cancer problem and raising our survival rates towards being the best in Europe.'