HPV test could soon be used alongside Pap test to spot cervical cancer
Published Saturday, May 10, 2014 10:04PM EDT
The Pap test has been the screening tool of choice for decades for spotting the first signs of cervical cancer, but some Canadian doctors say there's a better way now.
Several doctors and medical groups say it makes more sense to test for the DNA of HPV, the human papillomavirus, since certain strains of the virus are the cause of nearly all cervical cancers.
Groups such as Cancer Care Ontario say the DNA test for HPV is better because it is more accurate and patients can go longer between screenings. They say that while the Pap test can detect abnormal cells in the cervix, it can also miss some cancers.
Research has shown that HPV DNA testing is most effective in women 30 years of age and older. The test is not appropriate for women under 30 because transient or temporary HPV infections are common in this age group.
Dr. Joan Murphy, a gynecologist-oncologist at Princess Margaret Cancer Centre in Toronto and the clinical lead at the Ontario Cervical Screening Program says there is sufficient evidence now that using the HPV test as the first test would be better.
"In the women who are missed by a Pap test, who have pre-cancerous changes or are at risk of getting cervical cancer, we are confident that the HPV test will allow us to increase the pick-up rate in that population," she says.
The Pap test will not disappear but instead be used as a back-up test to look for abnormal cells only if the HPV test result comes back abnormal.
"The whole objective of cervical cancer screening is to reduce the frequency and the number of deaths due to cervical cancer," says Murphy, "And we have very good evidence that using the HPV test, incorporating it with the Pap, is going to improve the performance of these programs - i.e. reduce the frequency of cervical cancer," Murphy says.
But some doctors, like Dr. Norma Jo Waxman of the American Medical Women's Association in San Francisco object to the changes. They note that the HPV test is five times more costly, and may be so sensitive it may detect things that don't turn out to be cancer, leading to overtreatment.
"I suspect at some point we may be able to look at the HPV screening test as a tool, but at this time, it is probably way too early to consider its use for this," she says.
The HPV test is not part of regular cervical cancer screening anywhere in Canada. But Murphy says Cancer Care Ontario is working with Ontario's Ministry of Health to try to convince them that the test is economically reasonable.
In the meantime the Pap test isn't going away, with women still urged to get this test every three years to spot the disease that kills about 380 Canadian women a year.
With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip