New blood test may detect cancers earlier

A new blood test that identifies abnormal patterns in proteins may be marketed before the end of the year to screen for early signs of cancer or recurring cancers. The National Cancer Institute has begun a major study to prove if the blood test detects early relapse in ovarian cancer patients. If the test works as well as earlier research has suggested, it could win Food and Drug Administration approval for that use within a few years. It would take even longer to meet FDA's standards concerning whether the test also can spot ovarian cancer the first time it strikes. But two national testing laboratories aren't waiting. Quest Diagnostics and LabCorp hope to begin offering the blood test by prescription for women later this year who are at high risk of ovarian cancer because of genetic or family history. Despite caution from the test's own inventors that it's not yet ready for widespread use, federal law allows those labs to offer tests that aren't FDA-approved provided they meet other government certification standards, which the blood test developers are now attempting to do. The test screens for abnormal proteins that serve as markers for cancer development. But unlike current protein tests, the new screening method also looks for signs of protein interactions that can signal the onset of cancer. "There is a wealth of information in the blood that we didn't know about before," says NCI's Lance Liotta, who codirects the program. "We're finding an ocean of biomarkers." The researchers are now focusing on fine-tuning the test to screen for signs of ovarian cancer, one of the harder cancers to detect in its earliest and most treatable stages because of a frequent lack of physical symptoms. Currently the developers are studying the test to detect signs of recurrent cancer in women already diagnosed and treated for the disease, with plans to eventually expand their efforts to include screening for initial signs of ovarian cancer. They also are developing a test to screen for prostate cancer in men. In the planning stages are blood tests to screen for lung cancer and the earliest signs of pancreatic cancer, one of the deadliest forms of the disease.