Scandinavian researchers have found that HPV-based screening provides 60-70% greater protection against invasive cervical carcinomas compared with cytology-based screening.
In a follow-up study of four randomised trials, HPV-based screening for cervical cancer was compared with cytology-based cervical screening to investigate the relative efficacy of HPV-based versus cytology-based screening for prevention of invasive cancer in women who undergo regular screening.
A total of 176,464 women aged 20-64 years were randomly assigned to HPV-based or cytology-based screening. The women were followed up for a median of 6.5 years, with 107 cases of invasive cervical carcinomas identified during the study period.
The overall rate ratio for invasive cervical carcinoma among all women from recruitment until the end of follow-up was 0.60. In women with a negative screening test upon entry to the study, the ratio was 0.30. Women in the cytology group with an initial negative screen on entry, cumulative incidence of invasive cervical cancer was 15.4 and 36 per 100,000, 3.5 and 5.5 years post-entry to the study respectively. In the HPV group, this was lower at 4.6 and 8.7 per 100,000.
Rate ratios were lowest in women aged 30-34 years, but the efficacy of HPV testing did not differ significantly between women aged 30-34 and those over 35.
The researchers note that ‘HPV screening every five years could reduce the number of unnecessary colposcopy and biopsy procedures compared with more frequent cytology’ and say that their findings ‘support HPV-based screening with triage at prolonged intervals, starting at age 30 years’.
To update your knowledge on cervical cancer, why not try our CPD module Key questions on cervical cancer.