HPV screening beats cytology even in partly vaccinated patients

By Bianca Nogrady 
Human papillomavirus (HPV) screening is more effective than cytology at detecting high-grade precancerous cervical lesions, even in a population partly vaccinated against the virus, new data suggest. 

In the Compass study, published in PLoS Medicine, 4995 Australian women were screened using: liquid-based cytology followed by HPV testing in women with a cytological abnormality; HPV testing followed by liquid-based cytology in women who tested positive for high-risk viral subtypes; or HPV testing followed by dual-stain cytology in those women. 

Just under one-quarter of the women enrolled in the study were younger than 33 years of age, and therefore eligible for the HPV vaccine under the current immunisation program. 

The study found that significantly more high-risk cervical abnormalities were detected in the women screened using HPV testing, compared with those screened using the liquid-based cytology as the primary screen. 

The rates of cervical intra­ epithelial neoplasia grade 2+ (CIN2+) were 0.1% in the liquid-based cytology alone group (95% confidence interval [CI], 0.0%­-0.6%), 1% in the HPV testing plus liquid­-based cytology/colposcopy (95% CI, 0.6%­-1.5%) and 1.2% in the HPV plus dual-stain cytology (95% CI, 0.8%­-1.8%). The equi­valent rates of CIN3+ were 0.1%, 0.7% and 0.8% respectively. 

‘Compass is, to our knowledge, the first trial of cervical screening conducted in an HPV-vaccinated population and one of the first trials of HPV screening using a partial genotyping strategy in which women infected with the highest risk HPV infections (HPV16 and HPV18) are directly referred to colposcopy,’ the authors wrote. 

Lead author Professor Karen Canfell, Director of the Cancer Research Division at the Cancer Council NSW, said the results confirmed modelling of HPV testing in a vaccine­ exposed population. 

‘We’re always building the evidence base, and this is just yet another plank supporting the move to primary HPV screen­ing, which is essentially a more sensitive measure of assessing a woman’s future risk of develop­ ing cervical cancer,’ Professor Canfell told Medicine Today. 

‘It’s pertinent given that we’re now heading into the renewed cervical screening program which will be introducing HPV screening from December 1st.’ 

The renewed cervical screen­ ing program replaces two­ yearly cytology with five­-yearly HPV testing from age 25 years.
PLoS Medicine 2017; 14(9): e1002388. https://doi.org/10.1371/journal.pmed.1002388.

Picture credit: © Cavallini James/BSIP/SPL. Human papillomavirus (TEM).