OvaSure, a new blood test aimed at discovering ovarian cancer at an early, treatable stage is stirring up hope among women and doctors. The Food and Drug Administration (FDA), however, is skeptical of the test’s efficacy. The Society of Gynecologic Oncologists is skeptical of the new test as well. They are concerned that the new test will do more harm than good, with their biggest concern being the fact that it is premature and has not been validated enough for common use, so many women could have a false result leading to unnecessary surgeries being performed. In a recent study published in the journal Clinical Cancer Research, OvaSure correctly identified 221 of 224 blood samples taken from women with ovarian cancer or controls, identifying ninety-five percent of the cancers. It has a false positive rate, or identifying cancers that were not there, of 0.6%. A medical officer at the lab where the blood samples are sent indicated the test should be restricted to women at high risk for ovarian cancer and should be repeated to ensure there is not a false positive.
Many doctors are also worried that the test will not increase surgeries, but will reduce them in patients that should have their ovaries taken out preemptively. If the patient is at a higher risk for the cancer, it is not uncommon for the patient to decide to remove her ovaries even if there is not ovarian cancer. However, if this patient gets a negative reading on the test, she is less likely to have her ovaries removed and is therefore at a greater risk of developing ovarian cancer in the future.
More than 21,000 new cases of ovarian cancer will be diagnosed this year in the United States and more than 15,000 people are expected to die from it. According to the American Cancer Society, ninety percent of women who are diagnosed with ovarian cancer at its earliest stage, or when it is confined solely to the ovaries, will live at least five years; only twenty percent of cases, however, are detected that early. If the cancer is detected in its later stages, only thirty percent of the women will live for at least five years.
OvaSure’s debut also brings up the question of whether greater regulation is needed for assuring the validity of a variety of new diagnostic tests that are currently entering the market and are being used as a foundation for important treatment decisions. Two years ago, the FDA said it intended to regulate complex tests like OvaSure’s, but has yet to finalize the policy. OvaSure did not go through the FDA for review since the agency does not usually regulate tests performed and developed by a single laboratory; all OvaSure blood samples are sent to LabCorp for analysis. The FDA, however, has now asked LabCorp to discuss OvaSure, claiming the data appears insufficient to back the company’s assertions about the test. The chief medical officer for LabCorp claims the product has been authenticated in several studies this year and additional data is expected by the end of the year.