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Early cancer detection in the laboratory: The search for altered cells

Photo: DBenitostock / Getty Images

Almost half a million people are diagnosed with cancer every year in Germany alone. The chances of survival improve significantly if the disease is discovered early. Doctors therefore recommend regular check-ups. However, with conventional methods, not all tumors are detected in time or are already advanced. Scientists have therefore been trying to improve early detection for years.

An institute founded two years ago at the University of Cambridge is working hard on new types of tests. This is intended to detect cancer years before symptoms appear. The researchers at the Early Cancer Institute try to localize changes in cells ten to twenty years before the onset of the disease. How testing is done varies depending on the type of cancer.

At the beginning of March, the institute presented an early detection system for esophageal cancer. Patients swallow a small capsule-shaped pill that contains a tiny sponge. After the capsule has dissolved, it spreads into the stomach. As it moves up the esophagus, the sponge collects cells that are later examined. If the samples contain a certain protein, this is an indication of an increased risk of esophageal cancer, the researchers write.

“This is a big step forward in making this simple test routinely available outside of clinical trials,” believes Rebecca Fitzgerald, director of the Early Cancer Institute at the University of Cambridge. A timely diagnosis is crucial for the course of the disease. The test could be carried out relatively quickly by a doctor; most patients stated that the examination was painless.

The institute also researches genetic changes in the blood in order to detect certain types of cancer such as leukemia in the early stages. To do this, the scientists are working with 200,000 blood samples from women from routine examinations over the past decades. Using the historical samples, the researchers were able to retrospectively trace certain diseases in some samples. In some, they had already observed genetic changes ten to 20 years before developing blood cancer.

Cheap cancer tests: many promises, few marketable products

According to the researchers, cancers develop gradually. At an early stage it is still possible to block the growth of the diseased cells. The more advanced a tumor or ulcer is, the more difficult and expensive it is to treat. The institute, which is largely financed by donations, wants to focus primarily on types of cancer that are difficult to treat, including lung, pancreatic, esophageal and liver cancer, as well as leukemia.

Scientists around the world are researching such early detection tests. However, many of them are not yet ready for use. At the end of 2022, an international team of researchers reported on a method for the early detection of 14 different types of cancer in the journal “Proceedings” of the US National Academy of Sciences (“PNAS”). The researchers also advertised a simple and inexpensive test. This is intended to detect bladder cancer, breast cancer and prostate cancer using certain sugar compounds whose structure is different in cancer cells than in healthy cells. The test reportedly only costs $50.

At the time, experts warned that this test was still a long way from being used regularly. Before such cancer tests even come onto the market, extensive validation must take place in clinical studies with many more participants. Because even a small number of patients who tested false positive is an error rate that is too high when extrapolated to millions of users.

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