Simple Cervical Cancer Test Found

A simple test using vinegar could provide an inexpensive way to screen for cervical cancer and save perhaps tens of thousands of lives each year in Third World countries, researchers from Johns Hopkins University report in today’s Lancet.

Health authorities in several countries, whose residents cannot afford Pap smears, are already planning ways to use the new test.

The test is as effective as a Pap smear but “is much less costly and less complex to implement,” according to Dr. Beverly Winikoff of the Population Council. And a big advantage is that the results of the vinegar test--unlike those of a Pap smear--are available immediately, while the women are still in a clinic, she said.

Cervical cancer strikes an estimated 350,000 women worldwide, killing 200,000. That makes it the most common cause of cancer deaths among women in large areas of Asia, Africa and Latin America. It is caused primarily by the papilloma virus, and HIV-positive women are particularly susceptible to it.

The incidence of invasive cervical cancer and death can be reduced 90% or more by screening to detect it while it is in the earliest stages. More than 70% of women in industrialized countries such as the United States are screened at regular intervals with the Papanicolau smear.

“If you can find patients before they have advanced cervical cancer, you can virtually guarantee that they will not die of cervical cancer,” Dr. Paul D. Blumenthal of Johns Hopkins said in an interview.

But because of the cost of the Pap smear, only about 5% of women in developing countries receive it. There has therefore been great interest in developing a less expensive way to detect the cell proliferation that is an early sign of the disease.

Blumenthal and his colleagues at Johns Hopkins may have found such a test. All it requires is a nurse-midwife or other trained technician, a light source such as a flashlight, a bottle of vinegar and a simple speculum to help the nurse view the cervix.

Gynecologists have used acetic acid--the primary component of vinegar--for 40 years to help them view the cervix during colposcopy, a procedure in which the cervix is magnified tenfold to fortyfold with a microscope-like device. The acetic acid gives precancerous or cancerous tissue a whitish blush that is easily seen under the magnification, Blumenthal said.

The question was whether applying vinegar to the cervix would make the abnormal tissue visible without magnification. The Lancet study demonstrated that it would.

Working with researchers from the University of Zimbabwe, the team used nurse-midwives to screen 8,731 African women for cervical cancer. The nurses took a smear for the Pap test, then swabbed vinegar on the cervix and examined it. All those with positive results on either test, and some who tested normal, then received colposcopy, which is the usual follow-up test for confirming the presence of abnormal tissue.

In the second phase, 2,147 women were given the new test and underwent colposcopy, regardless of diagnosis, to check the accuracy of the new test.

The team reports in Lancet that the new visual test detected about 77% of all abnormal tissues, about the same rate achieved with the Pap smears.

The new assay “meets all the qualities of a good screening test,” Blumenthal said. “It’s cheap, it has good sensitivity, and it is easy to train people to do it. And everything needed to do it should be available at a family planning clinic.”

Blumenthal said that health authorities in Peru, Mexico and India have consulted him and are exploring ways to implement the new test. But he cautioned that testing alone is not sufficient: Positive tests must be followed up with treatment.

In most cases, that can be done fairly inexpensively, he said, using low-technology procedures. The abnormal tissue can be frozen with a cryogenic probe or cauterized with a hot probe. Either way, he said, after the suspicious tissue is destroyed, “it all grows back normal.” Chemotherapy and other treatments are used only when the cervical cancer is in an advanced stage.