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Monday, June 3, 2013 - 5:53pm
In some parts of the world, cancer patients are treated with some of the newest targeted cancer drugs which can cost more than$100,000 per year, while in other regions, patients don't even know they have cancer because they're not being screened.
But where pap smears are not available, there may be a decidedly low-tech way to screen for cervical cancer and reduce cancer deaths, according to a large clinical trial released Sunday at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago: swabbing a woman's cervix with vinegar.
This study out of India is one of the top five out of more than 5,300 studies presented at the conference. It was given a spotlight usually reserved for the newest blockbuster drug research.
Worldwide, there are 500,000 cases of cervical cancer and 250,000 women die from it each year, according to the World Health Organization.
"Unfortunately we have no cervical cancer screening program in India," where it's the number-one cancer killer among women, says lead study author Dr. Surendra Srinivas Shastri, "mainly because pap smear screening is not feasible." Shastri attributes lack of a resources, laboratory infrastructure and trained medical staff. A pap smear requires growing the cells from a sample and having a pathologist analyze them.
As a result, Shastri says, the cervical cancer incidence and mortality in India alone contributes to 30% of the global burden of this disease.
So he and his colleagues designed a trial to determine if using a simple visual test, which doesn't require a laboratory, can be an effective screening tool. They borrowed a tried-and-true method called visual inspection with acetic acid (VIA), where the cervix is swabbed with a 4% vinegar solution. This is something doctors in poor and rich countries do as part of a procedure called a colposcopy.
Gynecologists in the United States use this type of test for visualization in a colposcopy, says Dr. Carol Aghajanian, a gynecological expert from Memorial Sloan-Kettering Cancer Center in New York and ASCO spokeswoman. "What's new here is that it's being used as a screening tool."
Local women were trained for four weeks on how to administer the test, since doctors and nurses are in short supply in many areas of India.
Within just one minute, the person administering the test - using the naked eye and a light - can see if there are abnormal cells on the surface of the cervix; abnormal cells turn white, because the acid in the vinegar makes protein in the nucleus of the abnormal cells coagulate and become easily visible.
The fact that results are available immediately rather waiting for cells to grow in a lab is very important, since many women in rural India often have to travel to get some kind of medical care. If abnormal cells are seen, a small tissue sample is taken and biopsied. If cancer is detected, women can get the cancer care they need for free if necessary through India's health care system.
This study began in 1998 and was conducted in rural areas which Shastri describes as "naive of cancer, let alone cervical screening."
About 75,000 women were offered education and screened every 2 years; in the control group, about 76,000 women were educated about cervical cancer symptoms and not screened - the current standard of care in India.
The results were striking. Almost 90% of the women participated in the trial (in the United States, overall adult participation in clinical trials is 3%). Shastri says they found a 31% reduction in cancer deaths by using this vinegar test, suggesting that if implemented nationwide, it could prevent more than 22,000 cervical cancer deaths each year. This type of screening program could also be implemented in other developing countries and, Shastri says, possibly reduce the overall number of cervical cancer deaths each year by an estimated 72,000.
The researchers also found that there was no over-diagnosis, which is a huge problem in screening in general, says Shastri.
The study results are a "really big deal," because something so low-tech can help so many, says Dr. Bruce Roth, a cancer expert from Washington University in St. Louis and ASCO spokesman. "You can buy a lot of vinegar for $100,000, " says Roth.
The fact that local women who received training administered the test is also "a big public health benefit," says ACSO president Dr. Sandra Swain.
The study was funded by National Cancer Institute, part of the National Institutes of Health.