Human papillomavirus type 18 and rapidly progressing cervical intraepithelial neoplasia.
BACKGROUND
Human papillomavirus type 18 (HPV-18) is the second most frequent of the HPV types detected when squamous-cell cancer is diagnosed and the type most strongly associated with adenocarcinoma of the cervix. However, in cross-sectional studies, HPV-18 is rarely detected at the time of diagnosis of high-grade cervical intraepithelial neoplasia (CIN). We used a longitudinal study design to describe the occurrence of cytological abnormality after incident HPV-18 and HPV-16 infections.


METHODS
The analysis was based on 1075 women aged 15-19 years, who had normal cytology and were negative for HPV at recruitment from a single family-planning clinic, and who had further follow-up. The women reattended every 6 months, and samples were taken for cytological and virological examination.


RESULTS
The relative risk of a cytological diagnosis of borderline nuclear abnormality after exposure to HPV-18 was 2.06 (95% CI 1.24-3.43) and that after exposure to HPV-16 was 1.99 (1.32-3.01). The relative risks of mild dyskaryosis were 3.11 (1.86-5.18) and 4.76 (3.15-7.18), and the relative risks of moderate or severe dyskaryosis were 0.80 (0.24-2.65) and 2.85 (1.36-5.97). Time to acquisition of cytological abnormality was unrelated to the infecting type (p=0.88).


CONCLUSIONS
Our findings do not support the long-held view that the reason why HPV-18 infection is under-represented at the time of diagnosis of high-grade CIN is because HPV-18-associated disease rapidly progresses through the preinvasive stages of neoplasia. We suggest that the cytological changes detected after HPV-18 infection might understate the severity of underlying disease. This feature could compromise the effectiveness of screening programmes in reducing the frequency of HPV-18-associated cancers.
Woodman
Ciaran B J
CB
Centre for Cancer Epidemiology, University of Manchester, Withington, M20 4QL, Manchester, UK. ciaran.woodman@cce.man.ac.uk
Collins
Stuart
S
Rollason
Terry P
TP
Winter
Heather
H
Bailey
Andrew
A
Yates
Marie
M
Young
Lawrence S
LS
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D027383:Papillomaviridae / Q000302:isolation & purification* / Q000472:pathogenicity; D030361:Papillomavirus Infections / Q000145:classification / Q000150:complications*; D012720:Severity of Illness Index; D014412:Tumor Virus Infections / Q000145:classification / Q000150:complications*; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis / Q000473:pathology / Q000821:virology*