The female reproductive system
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A new test may be able to detect ovarian cancer earlier than existing diagnostic tools.
Epithelial ovarian cancer, which accounts for 90 percent of ovarian cancer cases, is one of the deadliest types of cancer: Only 30 percent of those with the disease live more than five years after diagnosis.
One reason for this is that epithelial ovarian cancer is asymptomatic for much of its course, so by the time people seek medical attention it has reached an advanced stage.
A blood test for a protein called CA125 is used to diagnose ovarian cancer, but it does not always detect the disease reliably. A population screening program in over 200,000 women in the UK failed to significantly reduce ovarian cancer deaths.
To develop a better test, Pan Wang of Peking University in China and his colleagues collected cervix from 219 women with cancer, including those with early stage ovarian cancer, late stage ovarian cancer, benign ovarian cancer and endometrial cancer. The uterine fluid contains cells and metabolic products, or metabolites, that come from the ovaries and fallopian tubes.
Using chemical analyzers called mass spectrometers, the researchers examined the fluid of 96 women to look for metabolites whose levels were markedly different for people with early-stage ovarian cancer. They identified a group of seven metabolites, including the amino acids tyrosine and phenylalanine, that could be used for diagnosis.
They then tested the fluids of the remaining 123 women for these seven metabolites and performed the CA125 test. The new test accurately identified most people with early-stage ovarian cancer and far outperformed the CA125 test in diagnosing earlier-stage ovarian cancer.
The results are promising, but the test needs to be validated in a larger group of people, says Eric Eisenhauer at Massachusetts General Hospital in Boston. “Effective nonsurgical tests for early-stage ovarian cancer have been elusive for more than five decades,” he says. “Most currently available early detection tests struggle to identify ovarian cancer while it is still in its early stages. I would like to see this profile validated in a larger prospective dataset, but this first report is promising.”
Sujata Sharma at the All India Institute of Medical Sciences in New Delhi points out that the study did not include people without cancer as a comparison, and that there may be other conditions that alter the profile of metabolites in similar ways.
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