A study published this week in Science reports promising results of a blood test designed to detect eight common cancer types by measuring circulating proteins and mutations in cell-free DNA. The study comes from the Johns Hopkins Kimmel Cancer Center at Johns Hopkins and has created a lot of buzz. We asked J. Leonard Lichtenfeld, M.D., MACP, deputy chief medical officer to share his thoughts about the study.
“The study reported this week on the potential of cell free DNA providing another option for the early detection of cancer represents elegant science. It is one more step down what we expect to be a long path of discovery to determine if this approach is not only effective at early detection but, far more important, also improves outcomes for those diagnosed with cancer.
“The test is one of several approaches with a similar focus on the early detection of cancer. Which tests will achieve this goal is not certain at this time.
“It is important to remember that it is one thing to advance the science and the technology; however it is something entirely different to demonstrate that the test will actually make a difference in saving lives. Notwithstanding the results of this study in patients who have already been diagnosed with cancer, it is possible that we may find that the test will find cancers early and we won’t be able to accurately determine where the cancer came from. Or we may learn that simply find these cancers early may not make treatment more effective or impact lives to the degree we had hoped for. These are answers we need.
“In simpler terms: we have a long way to go to demonstrate the utility and value of this test. We cannot make assumptions regarding the ability of this test to detect cancer early based on this study. We need additional research (which is being undertaken) to prove that it is possible to find cancer signals in the blood of patients before it is otherwise known they have cancers. Those studies are moving forward at this time.
“We have made assumptions in the past about the ability of blood tests to diagnose cancer early with—for example–tests for prostate and colon cancers. The prostate cancer experience should teach us that we need to prove value and utility before we again subject potentially millions of people to possibly unnecessary medical procedures and treatment which ultimately have not necessarily improved the length or the quality of their years.”