‘DIY’ test likelier than Pap smear to detect cancer
A do-it-yourself test women can perform at home to check for the virus that causes cervical cancer was three times more likely than conventional Pap smears to detect pre-cancers and four times more likely to detect invasive cancers, a large new study has found.
The “DIY” test — which checks for HPV, the human papillomavirus — is aimed at developing countries where women are screened only a few times in their lives. But the findings could be relevant to Canada.
According to the Public Health Agency of Canada, 15 per cent of women have never had a Pap test; 30 per cent haven’t been screened in the last three years.
HPV testing at home could be an alternative for women who cannot or do not get regular Pap smears, said Attila Lorincz, a professor of molecular epidemiology at the Wolfson Institute of Preventive Medicine at Queen Mary, University of London.
The Pap test detects abnormal cells in the cervix. HPV testing — which looks for the DNA of cancer-causing strains of HPV — can identify women at risk before any abnormal changes occur.
The new study, published this week in the journal, The Lancet, involved more than 20,000 women, aged 25 to 65, in rural Mexico. The women were randomly assigned to one of two groups: one group collected their own samples at home using a conical-shaped brush that’s inserted into the vagina and then placed immediately into a collection tube; the other had Pap smears at their nearest health clinic.
HPV “is really everywhere in the genital tract — not just on the cervix where the cancers arise,” Lorincz said.
Women with positive results in either test were referred for a colposcopy exam — a visual examination of the cervix that may include a biopsy.
The researchers looked at how well each test detected precancerous lesions, or worse.
HPV testing was three times more likely to detect pre-cancers and four times more sensitive in detecting more invasive disease, the team reports.
However, the DIY test had a higher false positive rate.