Test giant Laboratory Corp of America Holdings, known as LabCorp, has been sent a warning letter by the Food and Drug Administration (FDA) saying there are in violation of the law by marketing their $ 220 ovarian cancer test OvaSure.

OvaSure, developed by researchers at Yale School of Medicine, is a test that has been designed to calculate the possibilities a woman may have ovarian cancer, by measuring six proteins in blood samples, and has been available on the market since June, under a provision that exempts tests developed and offered by a single lab from the usual FDA review.

However, in a letter dated September 29th and released this week, the FDA determined that because the test was developed at Yale and that parts of it were manufactured elsewhere, it must meet the agency´s usual premarketing approval requirements, which could take up to a year.

Researchers around the world have been racing to develop a test that will detect ovarian cancer early, since it usually isn´t found until it has already spread outside the ovaries, when it is very often fatal.

According to the American Cancer Society, more than 21,000 new cases of ovarian cancer are diagnosed annually in the U.S., and more than 15,000 women die of it each year.

When ovarian cancer is caught early, the five-year survival rate is over 90 percent. But only about 20 percent of cases are caught that early, and when it is discovered later, the five-year survival rate is less than 30 percent.

In a study published last February in the journal Clinical Cancer Research, the test correctly identified 95 percent of cancers in 224 samples, with a false positive rate of 0.6 percent.

Yet OvaSure hasn´t been validated in the usual gamut of tests, and some cancer specialists fear that the test could yield too many false positives - causing women to undergo unnecessary exploratory surgery or to have their ovaries removed as a precaution - or false negatives, reassuring them when they might still be at risk.

Yale researchers have said that OvaSure is just one more piece of information that can help woman at high risk decide what to do, and that some are already having their ovaries removed prophylactically.

Tests for the gene mutations known as BRAC1 and BRAC2 can tell women whether they are at higher risk of breast or ovarian cancer, or both. But having the gene mutations is not definitive either. Women with a BRCA mutation have between a 15 percent and 45 percent chance of getting ovarian cancer at some point in their lives, but only one out of every eight cases of ovarian cancer involves one of those mutations.