HPV DNA testing may increase cervical cancer screening efficacy
MedWire News: Adding DNA-based human papillomavirus (HPV) testing to standard cytology-based cervical cancer screening permits earlier detection of pre-cancerous high-grade cervical cell changes, suggest findings from the POBASCAM study.
HPV testing has long been suggested as a more sensitive predictor for precancerous cervical changes than cytology, and these study findings provide further evidence of this, say Chris Meijer (VU University Medical Center, Amsterdam, the Netherlands) and co-authors.
The POBSCAM (POpulation BAsed SCreening study AMsterdam) study, published in The Lancet, involved 40,105 women aged 29-56 years. All were randomly allocated to receive cervical cancer screening by HPV DNA plus cytology testing (n=19,999) or cytology testing alone (n=20,106).
At baseline, the rate of detection of grade 3 or higher cervical intraepithelial neoplasia (CIN) did not differ significantly between both groups, at respective rates of 0.8% and 0.75%.
However, CIN of at least grade 2 was detected 25% more frequently by HPV DNA plus cytology testing than by cytology testing alone.
Of the original cohort, 16,750 of the DNA plus cytology group and 16,743 of the cytology-only group returned for a second screening test 5 years after the initial test.
At this second round of screening, CIN grade 3 was 27% less common among women in the dual-test group compared with those in the single-test group. Cervical cancer was 71% less common in the former than the latter group.
The authors say that this shows that the use of this dual screening test "leads to earlier detection of clinically relevant CIN grade 2 or worse, which when adequately treated, improves protection against CIN 3 or worse and cervical cancer."
In a related commentary, Hormuzd Katki and Nicolas Wentzensen (National Cancer Institute, Bethesda, Maryland, USA) remark that the POBASCAM study results indicate that a 5-year cervical cancer screening interval is "safe" when HPV DNA and cytology tests are performed together during cervical cancer screening.
Meijer and co-authors highlight that as HPV DNA tests can be performed accurately with self-collected cervico-vaginal samples, this screening method provides an opportunity to screen women who are reluctant to undergo conventional clinician-conducted cervical smear.
"Our results lend support to the use of HPV DNA testing for all women aged 29 years and older," conclude the authors.
By Lauretta Ihonor