Pap smears could help detect ovarian cancer
In what may be a life-saving development, a new study suggests that analysing DNA from pap smears could help detect ovarian cancers.
Ovarian cancer is the sixth most common cause of cancer death in Australian women, with one woman dying from the disease every 10 hours.
It is notoriously difficult to diagnose and because of that is often deadly.
But now researchers in the United States believe they may have found a way to speed up the detection of ovarian cancer by analysing the DNA from pap smears.
Luis Diaz, an associate professor of oncology at Johns Hopkins in Baltimore and a co-director of the study, says the findings are exciting.
"Normally when we come up with a hypothesis, the majority of the time it fails, that's just the nature of science," he told The World Today.
"But in this case we found that we did detect cancers but we were really excited when we detected so many endometrial cancers."
It is recommended all women over 18 who have ever had sex have a pap smear every two years as a way of detecting cervical cancer.
The test was updated recently to screen for human papillomavirus (HPV) using DNA testing.
Associate Professor Diaz suspects that ovarian and endometrial cancers likely shed a few cells that trickle down into the cervix and therefore could also be detected in a pap smear.
"As it stands right now, there are no approved screening tests for either endometrial or ovarian cancers," he said.
"All the work that's been done thus far has not suggested that one or another screening test is sufficiently effective or safe for use on patients, and part of that reason is because they're not sufficiently sensitive, and another reason is that they do often show that there a high number of false positives.
"What this initial study does is suggest that in endometrial cancers, we can detect almost 100 per cent - actually 100 per cent of the cases and in ovarian cancers we can detect about 40 per cent of the cases, even in their earliest stages of disease.
"In addition, we found no false positives in our study, suggesting that this may be an effective screening test for these diseases."
Work to be done
He says the method uses routine pap smears.
"Pap smears are performed every day on thousands of women around the world and this test would feel no different to the patient.
"It would be no different to the doctor or nurse performing the test, and would actually be done only in the lab and we'd take the same pap smear sample and look at that fluid from the pap smear or DNA for cancerous cells, that DNA having mutations.
"And it is challenging to look at multiple different mutations at once, but new technology called next generation sequencing has allowed us to do that quite effectively."
But Associate Professor Diaz warns there is still work to be done.
"We need to validate and reconfirm these findings in larger numbers of patients," she said.
Associate Professor Thomas Jobling, the chairman and co-founder of the Ovarian Cancer Research Foundation, has welcomed the study.
"I think it is a novel technique and it is promising, I believe. I think it is quite a long way from being able to be used as a screening test because it's only picking up 40 per cent of current known ovarian cancers," he said.
"I think it is good that it's not picking up false positives from normal patients and it's, as I say, it's a novel technique which is worthy of further evaluation."
The Baltimore study has been published in the journal Science Translational Medicine.