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No matter where they are in the world, people despair when they are diagnosed with cancer. For regardless of whether they are young or old, rich or poor, cancer often proves to be a death sentence, and indeed is one of the most common causes of death. In 2015 alone, cancer killed 8.8 million people. Lung cancer is one of the most prevalent kinds of cancer. The World Health Organization estimates that around 1.7 million people died of lung cancer in 2015. By way of comparison: cancer of the liver is the number two killer, responsible for around 800,000 deaths. One of the reasons why the number of lung cancer deaths is so high is that it is particularly hard to detect. Patients rarely show any symptoms in the early stages of the disease, so in many cases the cancer is not discovered in time. Once the cancer has finally been diagnosed, the patient generally has only five years left to live. It is a simple fact that the earlier the cancer is found, the better are the chances of a cure.
Yet current methods of diagnosing cancer in its early stages are not ideal due to their inaccuracy. They include blood and faecal examinations, as well as X-ray and computer tomography scans. All of these methods result relatively often in false positives, diagnosing a cancer where none is in fact present. Further tests are then carried out until the error is revealed, posing an additional burden on patients.
Something in the air
Scientists at the Max Planck Institute for Heart and Lung Research have now developed an entirely new method of detecting this type of cancer in its early stages. The new approach is based on the air we exhale. Dr Guillermo Barreto and his team are examining RNA molecules in exhaled air – tiny particles that can transfer genetic information to other cells. When we breathe out, the molecules are passed from the lung tissue into the exhaled air. The scientists make use of the fact that the molecules are different in people suffering from cancer. Barreto and his colleagues isolated the molecules and analysed the differences between those from healthy and those from sick people. In the end they were able to develop a model to diagnose lung cancer. In a study of 138 people, their breathing test was able to identify lung cancer correctly 90 percent of the time.
“The exhaled air analysis could make detecting lung cancer in its early stages easier and more reliable”, says Guillermo Barreto. “However, it will not replace conventional methods entirely. But it can be used as an additional means of better identifying early stages of cancer and reducing false-positive diagnoses.” Barreto now plans to conduct further clinical studies so that the new test can be used in hospitals as soon as possible.
Screening for all
The new test could make widespread screening possible for the first time. Currently no regular screening for lung cancer is carried out in Germany – only high-risk patients such as smokers are tested. If a lung carcinoma is discovered early enough, it may be possible to remove it surgically. If this is not an option, perhaps because the tumour is too small, radiotherapy may help. Patients suffering from lung cancer in its late stages tend to be in a great deal of pain. Often all that can be done is to combat the pain – as it is generally too late to fight the cancer itself.
Scientists at the Max Planck Institute for Heart and Lung Research study the structure and workings of the heart, blood vessels and lungs. Among other things, their findings are intended to contribute to a better understanding of diseases in these organs and to the development of possible treatments. At the International Max Planck Research School (IMPRS), young researchers can pursue a PhD in the field of heart and lung research. The Max Planck Institute for Heart and Lung Research cooperates with the German Center for Lung Research (DZL).