Liquid biopsy: The dream of the world's most prominent oncologist

Professor Bert Vogelstein, director of the Ludwig Cancer Research Center - Johns Hopkins, is one of the most prominent oncologists at the present time, who has won numerous awards for his sudden studies. turn on genes causing cancer.

However, what he always wanted to do, was not only to find out about cancer-causing genes, but to find a way to detect those mutations early in the patient's blood, at a time when cancer could still be Easy treatment, even treatment.

Believing in Vogelstein's dream, a group of investors poured $ 110 million to set up a company called Thrive Earlier Detection . This startup is the latest candidate to take part in an expensive race, developing blood tests that can screen and detect a range of cancers early.

One of the companies competing with them, Grail, has also raised more than $ 1 billion to develop a multi-functional cancer detection test.

Blood tests can also detect cancer early.

The concept of blood screening for early detection of cancer is also called "liquid biopsy" , and it is based on many research achievements that Professor Vogelstein and his colleagues at Johns Hopkins University, Kenneth Kinzler laid the foundation.

Liquid birth is based on the fact that tumors release mutated DNA and special proteins into the blood. They can sometimes be detected even in people with cancer who have no symptoms.

Together with oncologist Nickolas Papadopoulos, researchers at Hopkins last year announced a blood test that screened 16 genes and 8 proteins that could detect some cancers, including stomach cancer, ovary and liver.

Now, they are going to the end of another study, done with Geisinger - a major medical system in Pennsylvania. Participating in this study were more than 10,000 healthy women between the ages of 65 and 75. Scientists want to see if the test can detect cancer in these women 's bodies.

If any woman undergoes a blood test with a positive cancer test, they will be placed in a full body PET scanner to look for real tumors in the body.

Doctors at Geisinger said that this method actually detected some early cases of cancer and they are conducting treatment for these " lucky " patients. But it will take another year, new research results are published.

" We have some initial success, but this technology still needs to be closely monitored. It is still too early to confirm its success ," said Adam Congannan, a doctor at Geisinger.

Cancer releases DNA and protein into the blood before symptoms appear.

Early cancer screening tests are only recognized for use by indicators, such as how many cancer cases they find correctly, how many false detection results.

To overcome doubts, Professor Vogelstein said, tests will need to detect about 20% of actual cancers. " I almost always get a question from people about this. People ask:" Why can't you detect 70% of cancer cases? ".

However, in fact, finding one-fifth of cancer cases hidden in the body, even at the time when they can be cured is more valuable than any new cancer drug found. , but usually only prolong the life of the patient for a few more weeks.

The test gives a false positive result, meaning that it detects cancer when the disease does not actually appear in the body, which is more of a concern.

For any screening test aimed at the majority, such false positive results should be kept at no more than 1%, Professor Vogelstein said. He said, if you discover a lot of false positive results, you will have to do a lot of follow-up tests that are actually not necessary.

Professor Bert Vogelstein, director of the Ludwig - Johns Hopkins Cancer Research Center.

False positives both confuse the patient and cause waste in terms of the cost of testing, and the health consequences that the patient suffers, because these tests use radiation, which also harms the muscle. them.

Nevertheless, the Hopkins scientists' idea of ​​early cancer screening for liquid biopsy was commercialized by a company called PapGene, now renamed Thrive after receiving $ 110 million from a a group of elite investors including Third Rock, a joint venture and Blue Cross Blue Shield insurance company.

The company is led by Steven Kafka, formerly with Foundation Medicine, a DNA testing company in Cambridge, Massachusetts.

Bernie Marcus, a wealthy co-founder of Home Depot, who has funded a Geisinger study of $ 15 million (and has committed an additional $ 35 million to track an additional 40,000 people) will not have a role or stake. Financial in Thrive.

According to Professor Vogelstein: " He [Marcus] just wanted a blood test to detect cancer that was successfully developed before he closed his eyes. He did not care how it was done, as long as It is done well. "

Many types of cancer can be detected early by liquid biopsy.

Thrive will need to gather enough data to convince insurance companies to pay for the tests, which Kafka said could cost about $ 500 per case. To do that, insurance companies hope scientists will prove that early screening for cancer actually saves lives.

But this is not easy. Even the value of today's widely used cancer screening tests, such as mammography, is still debated after decades of application.

Instead, Thrive will try to prove that their method can detect cancer early, much earlier than other common measures. " If you can point out that you can detect cancer earlier, it is a reasonable extrapolation that you can say you will save lives, " Professor Vogelstein said.

" However, to really prove it, it will require hundreds of thousands or millions of patients. And you won't want to wait long."

Reference Technologyreview