NEW YORK (GenomeWeb News) – A study of nearly 132,000 healthy women in rural India indicates that testing for oncogenic strains of the human papillomavirus can reduce cervical cancer deaths in a previously unscreened population better than screening with either Pap test or visual inspection.
Researchers from India and France looked at whether a single round of cervical cancer screening with one of three methods — Qiagen's Hybrid Capture II HPV test, a cytology test, or visual inspection with acetic acid — could curb cervical cancer deaths among women aged 30 years to 59 years in India's Osmanabad region, where routine cervical cancer screening programs currently don't exist. Over the eight years of the study, HPV testing was the only method that significantly decreased cervical cancer death.
"Our study found that a single round of HPV testing was associated with a significant decline in the rate of advanced cervical cancers and associated deaths, as compared with the unscreened control group," lead author Rengaswamy Sankaranarayanan, a researcher with the International Agency for Research on Cancer in Lyon, France, and his co-authors wrote. "By contrast, there was no significant decline in the rate of death in either the cytologic-testing group or the [visual inspection of the cervix with acetic acid] group."
The results, appearing online today in the New England Journal of Medicine, suggest HPV tests can dramatically decrease cancer deaths in areas with relatively few screening resources — findings that have cervical cancer experts calling for efforts to introduce widespread HPV testing in India and other developing countries.
On the heels of the study, Qiagen announced last night that it plans to donate a million HPV tests, valued at about $30 million, over the next five years through its global access program. The company also plans to launch a mobile cervical cancer screening clinic in India and provide HPV testing products to 29 Chinese hospitals.
While the discussion surrounding cervical cancer screening in developed countries often revolves around ways to tweak or improve existing programs, much of the world has little to no cervical cancer screening. Consequently, roughly 80 percent of cervical cancer deaths occur in developing countries.
Some 20 percent of the global burden of cervical cancer falls on India, which sees tens of thousands of cervical cancer deaths each year and currently has no population-based screening program, Sankaranarayanan told GenomeWeb Daily News.
In an effort to determine which population-based screening method would most effectively reduce cervical cancer deaths in that country, Sankaranarayanan and his colleagues assessed 131,746 healthy women between the ages of 30 and 59 years old in the Osmanabad district, located in the southern part of India's Maharashtra state. Of the thousands of women involved in the study, just eight had had any sort of cervical cancer screening in the past.
The women were randomly assigned to four groups based on clusters of villages. Each group received one of three screening methods: the Qiagen Hybrid Capture II (also knows as the Digene test), which targets 13 oncogenic HPV strains, visual inspection of the cervix with acetic acid (also known as VIA), or a Pap/cytology test.
The control group received the current standard of care in India. Those women were not screened but received cervical cancer education and were encouraged to seek screening.
Each of the screening tests was offered only once and women who tested positive were provided with similar treatment — including colposcopy, and, if necessary, biopsy and treatment. The follow-up for the study lasted eight years.
Nearly 80 percent of the eligible women in each of the groups actually received screening. About ten percent of the 27,192 women screened by HPV testing group had positive results compared with seven percent of the 25,549 women screened by cytology testing and nearly 14 percent of the 26,765 women screened by visual inspection.
Among the three screening methods evaluated, only HPV testing significantly decreased cervical cancer mortality compared to the control group. Overall, 34 women assigned to the HPV testing group died of cervical cancer, compared with 54 women in the VIA group, 56 women in the cytology group, and 64 in the control group.
Although VIA and cytology testing slightly decreased cervical cancers and deaths compared with the control group, this decrease was not statistically significant.
Even so, Sankaranarayanan explained, while the study suggests HPV testing is the most effective screening method in this region, the cost of the Hybrid Capture II will likely prevent it from gaining widespread use in India and other developing countries.
Instead, Sankaranarayanan and his colleagues expressed enthusiasm about Qiagen's careHPV test, being developed by Qiagen in collaboration with the Bill and Melinda Gates Foundation and the PATH program. The careHPV appeared to be about as accurate as Hybrid Capture II in a study of about 2,500 Chinese women, published in Lancet Oncology last year.
In a statement yesterday, Qiagen said it is continuing to develop its next generation careHPV test, which is specifically designed to be used in low-resource countries. The company also said it plans to apply tiered pricing incentives to increase access to HPV tests in developing countries.
"Our results, combined with those of the Chinese study of the new HPV test, indicate that HPV testing is appropriate as a primary screening approach in low-resource settings for women who are at least 30 years of age," the researchers wrote.
"The implications of the findings of this trial are immediate and global: international experts in cervical-cancer prevention should now adapt HPV testing for widespread implementation," National Cancer Institute researchers Mark Schiffman and Sholom Wacholder argued in an editorial appearing in the same issue of NEJM. "Low-resource countries do not need to establish large cytologic-testing (Papanicolaou) programs whose effectiveness requires repeated screening."
"Cervical cancer is a remarkably uniform disease," Schiffman told GenomeWeb Daily News , "It's caused by the same HPV types all over the world." That means that results from the Indian study or elsewhere are relevant in other parts of the world, he explained.
Even so, Schiffman and Wacholder noted that such tests likely won't be cost effective for screening women under 30 years old, since HPV infections are common in young women and usually clear without causing disease. And, the duo added, testing too frequently could lead to over-treatment by detecting such transient HPV cases.
Still, in resource-poor places where screening only happens a few times over a woman's life, Schiffman and Wacholder emphasized that such testing appears to dramatically decrease cervical cancer risk.
For his part, Schiffman predicted that the careHPV test could attain widespread use within two years. As such, he argued that steps should be taken to start developing the appropriate infrastructure now.