Screening for the human papillomavirus (HPV) is more effective than Pap tests for protecting women against invasive cervical cancer, a new study suggests.
HPV causes most cases of cervical cancer. In a Pap test, cells from the cervix are examined under a microscope for abnormalities that can lead to cervical cancer. In HPV-based screening, the cells are initially tested for HPV.
If cell changes or HPV are detected in either type of screening, the patient is notified and undergoes further screening and examination, followed by treatment if needed.
In this study, researchers analyzed data from four clinical trials in Europe that compared the Pap test and HPV-based screening. The data came from more than 175,000 women, aged 20 to 64, who were followed for an average of six and a half years after having one of the screening tests.
Both methods provided similar levels of protection against invasive cervical cancer for the first two and a half years after the screening tests. But for the remainder of the follow-up period, HPV screening offered 60 percent to 70 percent greater protection than Pap test screening, according to the study.
The findings were published in the journal The Lancet and presented Saturday at a European meeting of experts in cervical cancer control and HPV-associated diseases.
The increased protection offered by HPV screening was particularly notable in women aged 30 to 35. The researchers also found that HPV screening every five years was most protective against invasive cancers of the cervix, compared with Pap test screening done every three years.