Researchers hope an experimental test will help doctors detect ovarian cancer earlier, when they still have a chance to cure the deadly disease.
The Canadian Cancer Society estimates 2,300 women are diagnosed with cancer of the ovaries each year and 1,600 die from it. “If it is detected in the early stages, the five-year survival is 90 per cent. If it’s detected in the late stages, the five-year survival is as low as 20 per cent,” says Dr. Aliza Leiser, a fellow in gynecologic oncology at Yale-New Haven Hospital in New Haven, Conn. “It is almost always diagnosed in the late stages, unfortunately, so the most powerful tool we have to combat ovarian cancer is early detection — and that’s what we hope to do with this (test).”
The test measures levels of six different proteins in blood serum. Most of the proteins aren’t directly related to cancer, but their production may be altered when a tumour is growing in the body.
Leiser and her colleagues evaluated the accuracy of the test in 156 ovarian cancer patients and 363 healthy women. The results indicated that for every eight women who undergo surgery on the basis of the test results, one will have ovarian cancer and the other seven will have a benign condition. A further study of the test is underway.
Leiser says the test would probably not be a single-step cancer screening. Like many tests, it would be a two-step model: Those who had an abnormal blood test would undergo an ultrasound scan to determine if surgery was needed. She says the blood test could have the potential to become a general screening test like a mammogram or Pap smear. “This would essentially be like a mammogram of the ovary.”