Diagnosis 2.0

by Courtesy breastcancer.org; iStockphoto Sooner is Better: The first protein-based blood tests may be able to spot breast cancer years before doctors can, helping thousands of women seek earlier treatment. Courtesy breastcancer.org; iStockphoto

By the time a doctor diagnoses you with cancer or a neurodegenerative disease, you may have been living with it for years—a troubling fact, given that early detection is the most important factor in successful treatment. Now, Power3 Medical Products, a biotech firm in Houston, Texas, has developed simple, low-cost blood tests for breast cancer, Alzheimer's and Parkinson's that will allow physicians to spot disease the moment it shows up in a patient's body—years earlier than today's most advanced technologies can catch it. "With our tests, you don't have to wait around for 6 or 10 years [to spot the problem]," says CEO Steven Rash.

Power3's breast-cancer test, to be released early next year, is the first diagnostic to emerge from a fast-growing field known as proteomics that looks for telltale proteins in a person's blood, just as genetic tests screen for disease-causing genes. Genes give instructions, but proteins do the body's work, so although genetic tests can determine whether a person has a gene that increases his or her risk of developing a specific disease (women who carry the BRCA1 or BRCA2 genes run a greater risk of developing breast cancer, for example), proteomic tests like Power3's can tell whether the gene—and thus, the disease—is active, long before physical symptoms appear.

The new breast-cancer test is much less invasive than a mammogram or biopsy. A doctor samples a patient's blood and sends it to Power3's lab, where scientists search for 22 irregular proteins that Power3 has identified as early signs of breast cancer. Initially the test will debut in 40 clinics that treat women at high risk for breast cancer, Rash says. Women under 40 years of age with high-risk genetic or family factors should benefit the most, he adds, because their denser breast tissue makes mammography significantly less effective.
Scientists have been working to develop proteomic tests for the past three years, but they were derailed by inconsistent test results. Early data indicate that Power3 has overcome this challenge. In a blind trial of 60 blood samples provided by Mercy Women's Center in Oklahoma City, the test scored a 97 percent rate of identifying cancer in samples from diagnosed patients and a 93 percent rate of correctly identifying healthy women as cancer-free. A second 100-patient trial will be completed by the end of the year. In comparison, mammograms miss up to 30 percent of breast cancers, and 75 percent of the biopsies performed after an irregular mammogram prove benign.

"There's tremendous promise in proteomics," says Lance Liotta, a proteomic scientist at George Mason University. "The early diagnosis and individualized therapy coming out of the science is going to change medicine." But Power3's results are not conclusive, so until further testing confirms the test's reliability, it will just supplement existing tests.

The company is also validating protein-based tests for Parkinson's and Alzheimer's, the latter an affliction for which the only conclusive test is currently an autopsy. Among the possible benefits of a proteomic Alzheimer's test, due out late next year, would be the ability to definitively separate sufferers from those with other neurodegenerative problems, now a major obstacle to running effective clinical trials of drugs for Alzheimer's.

"Power3 won't do it all," says Essam Sheta, the company's director of biochemistry. "But my expectation is that in the next five years, we as a scientific community will be able to develop diagnostic tests for many, many types of diseases."