Updated

A cheap method to detect cervical cancer using vinegar, cotton gauze and a bright light could save millions of women in the developing world, experts reported Friday.

The study, published in The Lancet medical journal, found a simple visual screening test to look for the early signs of cervical cancer reduced the numbers of cases by a quarter.

"This is a landmark study," said Dr. Harshad Sanghvi, medical director at JHPIEGO, an international health organization affiliated with Johns Hopkins University that has worked on preventing cervical cancer in poor countries. Sanghvi was unconnected to the Lancet study.

Cervical cancer is largely preventable. It causes about 250,000 deaths every year and is the second-most common cancer in women. Nearly 80 percent of those women are in the developing world.

The visual screening test is done by a nurse or trained health care worker who washes a woman's cervix with vinegar and gauze using a speculum to hold it open. After one minute, any pre-cancerous lesions turn very white and can be seen with the naked eye under a halogen lamp.

Researchers from the International Agency for Research on Cancer in France and their colleagues from Tamil Nadu in India used the technique to screen 49,311 women in Dindigul district, India, from 2000 to 2003. When pre-cancerous lesions were found, health care workers gave immediate treatment to destroy the abnormal cervical tissue.

Another 31,343 women received standard care. They were told to watch for signs and symptoms of cervical cancer and encouraged to visit health care facilities where screening was available. These women were tracked from 2000 to 2006.

There were 167 cases and 83 cervical cancer deaths in the women who received the screening, compared with 158 cases and 92 deaths in those who didn't. That represents 25 percent less cervical cancer and a 35 percent lower death rate among those screened.

All of the women in the study were healthy and between 30 and 59 years old when the study began. The research was funded by the Bill & Melinda Gates Foundation.

Previous research has shown visual screening is almost as effective in catching cancer as Pap smears, a more expensive technique used in the West, which involves scraping cells from the cervix to be examined under a microscope in a laboratory.

"This is the final proof that with an extremely simple test, we can have a dramatic impact on cervical cancer rates," Sanghvi said.

Experts think that the simple, inexpensive technique could be rolled out across the developing world relatively easily. Pilot projects are already under way in a handful of countries in Asia and Africa.

"This study has given us a road map of how we can deliver this kind of screening widely," said Dr. David Kerr, Rhodes Professor of Clinical Pharmacology and Cancer Therapeutics at Oxford University. Kerr was not involved in the study.

Still, the test isn't perfect. It can produce many false positives, so health care workers giving the test must be properly trained. Also, the test cannot be used in post-menopausal women or in women who have had more than two or three children, since pre-cancerous lesions in those women develop in parts of the cervix not normally visible.

But other tests, like Pap smears or those to detect the human papillomavirus, or HPV, which can cause cervical cancer, are too expensive for poor countries to adopt. "The visual screening approach is within our grasp," Sanghvi said. "Visual inspection won't have as dramatic an impact as the sophisticated tests, but will have 70 percent of the impact for a minuscule cost."

Officials are already working on a cheaper version of the cervical cancer vaccine, which currently costs about $360 per dose, for the developing world. Together with stepped-up screening, doctors think that cervical cancer might one day be wiped out as a major health problem.