Developing biochemical tests for cervical cancer

Liu wakes and rises from her bed, careful not to disturb her husband and daughter. She hurriedly goes about her chores of feeding the chickens, watering the vegetable garden, and preparing the morning meal; soon Mother-in-Law arrives to watch Daughter.

“Why are you going to the hospital when there is so much work to be done in your home? Do you feel sick?” asks Mother-in-Law. Liu explains that the village elders and the barefoot doctor came to her house a month ago. They asked her to join several other women from the village to participate in a screening program for a women’s cancer—cervical cancer. If she was ill the hospital would pay for her treatment, plus she would be helping to develop a new test that would be easier to use.

Liu knew a woman in the village who had suffered from this disease. Apparently Che had blood in her underwear for a very long time, but with two children, she did not have enough time to see the doctor at the county hospital. She went to see the village doctor for some traditional Chinese medicine, but it did not help the bleeding. When Che was so ill that she was unable to cook for her family, she asked her husband to take her to the hospital. The doctor told her that she had cervical cancer and that she needed a very expensive surgery to remove the cancer. Luckily, Che’s elder brother was able to get a job in the city earning the money for Che to have the life-saving operation.

“I think this new test will be a good thing. It will help women not to cause their family much debt—and keep them alive to take care of their families,” Liu told Mother-in-Law. Then she heard the noise of the bus from the county hospital coming down the dirt road. She hurried to join the women waiting by the side of the street.

The stories of Liu and Che are composites of experiences common in China and other developing countries, where 200,000 women each year die from this preventable disease—and often in the prime of their life. More than 80 percent of the new cases identified annually occur among women in developing countries. PATH’s work on a new, biochemical screening test will decrease the disproportionate burden they carry.

The need for a new test

In many wealthy countries, Pap smear screening programs help keep cervical cancer rates relatively low. But they are only effective because of a robust health system:

• Women generally have access to regular, repeated screenings at health facilities. Repeated screenings are important because the Pap test itself, based on examining cells, is not very sensitive.
• Pathology laboratories with expensive equipment and supplies and highly trained personnel are available for processing samples.
• When test results come in several days or weeks after the screening visits, women generally can be contacted and are available for follow-up and treatment when necessary.

Developing countries often lack this complex and expensive infrastructure, prohibiting women from life-saving screening.

Biochemical tests

Working with private-sector collaborators, PATH is developing sensitive, biochemical tests for use in low-resource settings. The new tests will be safe, accurate, inexpensive, and acceptable to women and health care providers.

There is no one-size-fits-all approach to cervical cancer screening, so two different test formats (using different technologies) are in development. Both tests will be based on a cervical or vaginal swab, provided by the woman herself or obtained by a health care provider. Health workers with minimal training and equipment will be able to process either test in one day.

In some areas, women are screened in mass campaigns (like the one Liu attended), resulting in a large volume of tests to be processed in a short amount of time. In response to this need, PATH and Digene Corporation are developing a rapid “batch” test that allows processing of multiple specimens in two hours or less. The test will detect DNA from the human papillomavirus, the virus that causes cancer of the cervix.

Local clinics also play a key role in screening. In order to accommodate this testing environment, PATH and Arbor Vita Corporation are developing a rapid “strip” test, similar to a pregnancy test, that detects a viral protein marker. It will allow a woman to be tested and receive her results in one visit to a health center.

Partners in the public and private sectors

PATH’s two private-sector partners for this project, Digene Corporation and Arbor Vita Corporation, are committed to making tests accessible in low-resource settings.

We are also partnering with preeminent cancer research organizations to develop and eventually field-test the prototypes. In China, we are working with the Cancer Institute Chinese Academy of Medical Sciences, and in India, our partners will be the International Agency for Research on Cancer and Tata Memorial Hospital. A technical advisory group composed of international experts in human papillomavirus and cervical cancer prevention is helping to monitor and guide the project.

Of course, test development is only one part of making cervical cancer prevention available the world over. Other activities will prepare the way for the tests being used once they enter the market:

• Assessing women’s needs and preferences to make sure the tests are acceptable to them.
• Exploring the understanding and attitudes of clinicians and policymakers who must use or endorse the tests.
• Developing business and commercial strategies for successful manufacture, assembly, and distribution.
• Modeling the costs of producing the final tests to make sure they will be affordable in low-resource areas.

This work builds on PATH’s role as the coordinating agency of the international Alliance for Cervical Cancer Prevention whose aim is to clarify, promote, and implement strategies for preventing cervical cancer in low-income countries. The tests could be the next breakthrough in making cervical cancer prevention available to all women, no matter where they live.

Photo: Jacques Bablon.