(RxWiki News) Traditionally, the Pap smear has been used to screen for cervical cancer. A new study has shown that there may be a better screening method for this female cancer.
After analyzing the results from four large trials, researchers discovered that HPV (human papillomavirus) testing protected more women from invasive cervical cancer than cytology (Pap smears).
Certain subtypes of HPV, a sexually transmitted virus, cause nearly all cervical cancers.
Based on this study’s findings, the authors have suggested that HPV testing be used every five years instead of cytology every three years to screen for cancer of the cervix in women 30 and older.
"Find out how often you should be screened for cervical cancer."
Led by Guglielmo Ronco, MD, from the Center for Cancer Epidemiology and Prevention in Turin, Italy, a team of researchers analyzed the results of four European trials that looked at the effectiveness of HPV testing compared to cytology to prevent invasive cervical cancer.
The four trials from Sweden (Swedescreen), the Netherlands (POBASCAM), England (ARTISTIC) and Italy (NTCC) enrolled 176,464 women between the ages of 20 and 64.
Cervical screening tests are designed to detect abnormalities found in the cervix that can lead to cancer.
In cytology-based screening, cells from the cervix are examined under a microscope. The HPV-based tests look for the presence of high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68) that have been linked to cervical cancer.
If suspicious changes are found with either test, the woman is referred for further testing, examination and treatment, if necessary.
Trial participants were randomly assigned to receive either HPV-based testing or cytology-based screening.
The women were followed for an average of 6.5 years, and the researchers found that both testing methods were similarly effective during the first 2.5 years of screenings.
In later years, however, fewer cancers were found in the women who had received HPV testing.
The additional protective benefits of HPV testing were particularly strong in women between the ages of 30 and 35.
The authors wrote that “...data from follow-up analysis of four large randomized cohorts show that HPV-based cervical screening provides 60–70 percent greater protection against invasive cancer compared with cytology-based screening.”
Based on these findings, the researchers have suggested that starting at age 30, women undergo HPV-based cervical cancer screenings every five years instead of cytology every three years.
dailyRx News spoke to dailyRx Contributing Expert Chi Pham, MD, a medical oncologist with Texas Oncology and a member of the medical staff at Baylor All Saints Medical Center at Fort Worth, about this study. She told us that the standard cervical cancer screening in the US is cytology with or without HPV testing.
“This study instead points out that HPV testing may be superior to cytology in terms of protecting women from developing cervical cancer,” Dr. Pham said. “In addition, the screening interval could be lengthened to five years rather than three. However, this approach is only recommended for women 30 years old or older."
Dr. Pham cautioned, “One concern I have is the higher false positive rates with HPV testing. This may lead to increased diagnostic procedures.”
Findings from this study were published November 3 in The Lancet Oncology.
Funding for this research was provided by the European Union, Belgian Foundation Against Cancer, KCE-Centre d’Expertise, IARC, The Netherlands Organisation for Health Research and Development and the Italian Ministry of Health.
No conflicts of interest were reported.
