A major trial in India has taken centre-stage at the American Society of Clinical Oncology meeting in Chicago after it demonstrated that a simple test using vinegar has slashed the rates of cervical cancer mortality in the country.

The randomised study conducted among 150,000 women in India over 15 years revealed that biennial visual inspection with acetic acid (VIA), or vinegar, delivered by primary health workers, reduced cervical cancer mortality by nearly one-third. Speaking to journalists at ASCO, lead study author Surendra Shastri of the Tata Memorial Hospital in Mumbai noted that cervical cancer is the leading cause of cancer death among women in many developing countries, where there is little or no access to Pap screening.

In the study, women aged 35-64 years with no prior history of cancer were randomly assigned to four rounds of VIA screening which involves the application of 4% vinegar to the cervix (75,360 women) over two years or no screening (76,178 women). The latter received one round of cancer education and were asked to report any symptoms they noticed on the basis of what they had learnt.

With the VIA test, after 60 seconds the cervix is examined with the naked eye using a lamp. Pre-cancerous tissue turns white when vinegar is applied, whereas healthy tissue does not change colour. The results are known immediately, a huge advantage in rural areas where women might travel for hours to see a doctor, and all trial participants were offered free cervical cancer treatment, if diagnosed.

Dr Shastri noted that the incidence of invasive cervical cancer was comparable in the two groups, suggesting that screening did not lead to overdiagnosis. Screening with VIA resulted in a 31% reduction in cervical cancer-specific death rates and the researchers estimate that this strategy could prevent 22,000 deaths in India and close to 73,000 in poor countries worldwide.

Cultural barrier overcome

Dr Shastri noted that this is the first trial to identify a cervical cancer screening strategy that reduces mortality and is feasible to implement on a broad scale. He told reporters that the healthcare workers who carried out the test were trained up after four weeks (with a one-week refresher) had to "pass through several barriers" to gain the trust of women and religious groups.

He went on to say that his team is working with the Indian government and state health authorities to make the scheme available to women throughout the country; implementation could come in the next two years.

Speaking about the study, Electra Paskett, an ASCO spokesperson and expert in gynaecologic cancers from Ohio State University, stressed that this approach is suitable for areas where Pap screening testing is not available. However, she said that this trial and other similar analyses "have demonstrated that the accuracy of these programmes is comparable".