Potential early warning system for lung cancer identified

The study, published in the journal Thorax, found that changes in the blood can be detected which signal the presence of lung cancer, and that these changes can be present years before outward symptoms become apparent.

Early diagnosis means earlier treatment - which is much more likely to be effective.

Worldwide, lung cancer kills around 900,000 people every year, and can take 20 years or more to develop fully. But it is usually only picked up at an advanced stage, when the chances of successful treatment are slim.

As yet, there is no effective early warning system to detect the disease in its early treatable stages, and the dismal long-term prospects of patients with lung cancer have changed little in the past 30 years.

The research team at Nottingham, in collaboration with a team at Johannes Gutenberg University in Germany, analysed blood (plasma) samples from 50 healthy volunteers and 104 people with different types of lung cancer.

They tested for autoantibodies — immune system proteins directed at the body’s own tissues, in response to specific chemical signals in the body. They looked in particular for a panel of seven autoantibodies, which are associated with ‘solid tumours,’ such a lung, breast, ovarian, and prostate cancers, and triggered when cancerous changes are taking place.

They found the presence of all seven autoantibodies, and very high levels of at least one of the seven autoantibodies in almost eight out of 10 samples taken from patients with confirmed lung cancer.

And they were found in eight out of the nine patients whose cancer had not infiltrated the lymph nodes, the body’s ‘gatekeepers’. This indicates that the disease had not yet spread elsewhere and offers an 80% chance of a cure.

Only one healthy volunteer had more than one of these autoantibodies in their blood.

Other research has indicated that these autoantibodies can be picked up as early as five years before clinical symptoms start to show.

This study is one of a number of studies looking at autoantibodies in cancer.

In a previous study, published earlier this year in the Annals of Oncology, the researchers found abnormally high levels of specific autoantibodies in patients with breast cancer, prompting them to suggest that a test for these could be added to the screening programme and may be helpful as an aid to the diagnosis of early breast cancer, especially in individuals at risk of developing the disease such as those with a strong family history. This study also demonstrated that these autoantibodies could be detected before clinical presentation.

Following on from this, a blood test for the early detection of breast cancer is to be released by Oncimmune (www.oncimmune.co.uk), a spin-out company from The University of Nottingham, in 2008 in the USA. It is envisaged that a test for lung cancer would follow soon after.

The authors argue that the lungs are especially sensitive to radiation, so repeated chest x-rays are not ideal for picking up lung cancer. A blood test, on the other hand, is cheap relative to imaging tests, with no side effects, and the panel can be optimised to identify more or different autoantibodies in lung and other cancers.

They suggest that the blood test could be used for people at increased risk of developing the disease, such as smokers and passive smokers. If the test was positive, they could then be referred for more detailed scans, such as computed tomography (CT) or magnetic resonance imaging (MRI).