A Screen With Fewer Holes

World Health
Cancer patients share a bed in the female ward of Tanzania's cancer institute in the capital Dar es Salaam. REUTERS/Katrina Manson

Cervical cancer ought to be an easily conquered disease. Slow to develop, it gives doctors a window of up to 10 years to detect and treat its occurrence. That's one reason its incidence and mortality rate have plunged more than 75 percent in the United States since the 1940s, in one of the country's greatest cancer-prevention victories.

But that success has yet to reach the developing nations, where the World Health Organization says 85 percent of humanity's cervical-cancer deaths occur. In India, which has roughly one sixth of the planet's 7.2 billion people, the mortality rate is approximately five times that of the United States.

With luck, however, that toll may be headed for a steep drop. Portland, Oregon-based Preciva is currently testing a portable device that could revolutionize cervical screening and save hundreds of thousands of lives annually around the world, not to mention make life easier and safer for women in the developed world as well. "We've seen massive decreases in deaths from cervical cancer," says health-services researcher Anaïs Tuepker, who co-founded Preciva with her husband, physicist and engineer Craig Miller. "But in a lot of the world women don't get screened — and those are the women who are dying."

The standard method of cervical-cancer detection, the Pap smear, is simply not practical in many parts of the world. The technique requires extracting cell samples from the cervix and sending them to a laboratory for testing by a trained technician. Even where the necessary resources exist, the lab work can be expensive and time-consuming, typically delaying results by several weeks. Not only that, but the sampling procedure can miss problem spots on the cervix.

Preciva hopes to surmount those difficulties with a battery-powered device its makers are calling an mColposcope. The motor-driven device will use bioimpedance — the body's response to imperceptibly tiny electric pulses — to seek out cells that are enlarged or arranged in an irregular way. During a complete 40-second exam, the device's disposable tip will emit some 10,000 signals, charting the entire cervix, square millimeter by square millimeter. At the procedure's end, the result will be a color-coded map showing any abnormalities that may call for medical follow-up.

Preciva aims to price the reusable handpiece at roughly $200, and tips would cost several dollars each. The main thing is to make the device as simple as possible to operate. "We're trying to design it so that it can be used by people with minimal training," says Tuepker, "so a community health worker, who is a peer in a village and is doing health education, could do it in people's homes in private, which could overcome barriers to people being willing to get screened."

If the device proves itself in clinical tests and wins government approval, Tuepker wants to send it first to mobile health teams in India. But it could eventually prove valuable in U.S. doctors' offices as well. Everyone wants immediate, accurate results. And because it maps the entire cervix, the device could monitor suspicious spots on the cervix with successive screenings, in case they're benign and will heal on their own. "If it's a very low grade abnormality, this kind of test would encourage you to do what is probably the medically sound thing to do, which is to wait," says Tuepker. "You may very well not need treatment."

Still, Tuepker says, the real payoff will be the lives saved in the world's poorest places, "for women who are in a setting where they're not getting screened every year, or every three years, or every five years—they're lucky if they screen once in their life." For those women, Tuepker says, you need a test that will do the best possible job of detecting the disease. "And that's what we believe our test will do."