A new version of a screening test for ovarian cancer may reduce the number of deaths from the disease, researchers reported last week.
The findings, published in The Lancet journal, come from a 14-year study of more than 200,000 women in Britain.
The study results have been long awaited because ovarian cancer has a poor prognosis. The disease has no symptoms in its early stages and can progress rapidly, so most cases are advanced by the time they are found. Only about 45 per cent of ovarian cancer patients are still alive five years after diagnosis.
Past efforts to find a screening method have focused on two tests: ultrasound examinations of the ovaries, and a blood test to measure CA125, a tumour marker sometimes linked to early-stage disease.
But in previous studies, those tests did not work: they did not lower the death rate, and they produced too many false-positive results that led healthy women to have unnecessary surgery.
The Lancet study also used CA125, but in a different way. Instead of declaring a certain level abnormal, the researchers developed a mathematical formula that took into account a woman's age and the degree of change in CA125 over time, and calculated a risk score.
The study was paid for by the British government and the Eve Appeal, a charitable group in Britain.
While promising, it needs more research to determine whether the benefits hold up.
"We need to follow up to confirm that this is absolutely significant throughout," said Dr Usha Menon, an author of The Lancet article and head of University College London's gynaecological cancer centre.
The study passed two out of three tests of statistical significance, which means the apparent benefits of screening might have been due to chance.
Dr Menon said a few more years of monitoring the participants would resolve that question.
Experts who did not take part in the study were varied in their optimism about it.
"It is good news because ovarian cancer is a serious problem," said Dr Robert Smith, vice-president for cancer screening at the American Cancer Society.
"The incidence is not high, but it has a high mortality rate and we've not been able to offer women much with respect to early detection. This has the potential to change that," he said.
Dr Tanveer Mir, chairman of the board of regents of the American College of Physicians, said she thought the test had great promise and expected that the college's special task force on screening tests would evaluate the study and consider endorsing it.
Dr Karen Lu, chairman of the department of gynaecologic oncology and reproductive medicine at the University of Texas MD Anderson Cancer Centre, called The Lancet research "a solid triple, but not a home run".
She said the findings meant a screening test might become possible in a few years.
An important strength of the method, she said, "is that they don't do many unnecessary surgeries".
To save one life, the researchers calculated, 641 women had to be screened annually for 14 years. For each ovarian cancer detected, 2.2 women had surgery that turned out to be unnecessary - a rate that researchers consider low. The rate of major complications from those operations was 3.1 per cent.
Dr Saundra Buys, professor of medicine and medical director of the high-risk breast cancer clinic at the University of Utah's Huntsman Cancer Institute, pointed out that ovarian cancer is not amenable to screening because of its lack of symptoms and aggressive growth.
In Singapore, ovarian cancer is the fifth most common cancer among women, with 1,646 new cases diagnosed between 2009 and 2013.
THE NEW YORK TIMES