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LONDON – Vaccinating women with cervical intraepithelial neoplasia (CIN) against human papillomavirus (HPV) during surgical removal of the dysplastic tissue lesions may reduce the risk of recurrence and other HPV-related diseases, scientists report BMJ (2022; DOI: 10.1136/bmj-2022-070135).
The HPV vaccination can protect against CIN. In Germany it is recommended for girls and boys aged 9-14. In the UK it is offered to girls and boys aged 12-13.
Konstantinos S. Kechagias, from the Department of Surgery and Cancer at Imperial College London, and his colleagues wanted to find out whether women who already have high-grade CIN that needs to be surgically removed could still benefit from the HPV vaccine.
“Women with CIN who undergo local surgical treatment are at high risk for recurrence of pre-invasive and invasive cervical cancer and other HPV-related diseases,” they write. “Women with high-grade CIN may be particularly susceptible to HPV infection and may be rapidly reinfected.”
CIN is divided into 3 stages, from mild (CIN1) to moderate (CIN2) to severe (CIN3) dysplasia. Kechagias’ study team analyzed the results of 18 studies, including 2 randomized controlled trials (RCTs), 12 observational studies and 4 post-hoc analyzes of RCTs.
They report that the two RCTs had a low risk of bias, while the rest of the studies had a moderate to high risk of bias. The women were followed up for an average of 36 months. Reducing the risk of recurrence by more than half
The meta-analysis found that the risk of recurrence of high-grade preinvasive dysplasia (CIN2+) was reduced by 57% in women vaccinated against HPV compared to those who did not receive the vaccine.
The effect was even stronger – a 74% reduction – when the risk of CIN2+ recurrence was assessed for disease associated with two high-risk types, HPV16 and HPV18; they are the cause of most cervical cancers. Even with higher grade CIN3, the risk of recurrence was reduced in the vaccinated patients.
No data for effect on non-cervical diseases
Due to a lack of evidence, the authors could not determine the benefit of HPV vaccination with regard to the recurrence of HPV infections and other non-cervical diseases such as lesions on the vulva, vagina and anus as well as genital warts.
The authors acknowledge that their analysis has a number of limitations. Not only were most studies observational and of low to moderate quality, they also had relatively short follow-up periods, preventing assessment of long-term effects. In addition, most studies did not report the age of the women, and many studies did not control for risk factors such as smoking.
Protection has yet to be confirmed
Nevertheless, Kechagias and his colleagues emphasize that the use of strict inclusion criteria and the rigorous and systematic evaluation of study quality and risk of bias suggest that the results are robust. Therefore, they conclude that HPV vaccination at the time of surgical removal may reduce the risk of CIN recurrence, especially when related to HPV16 or HPV18.
However, the data is not clear due to the low quality of evidence. Therefore, large-scale, high-quality RCTs are needed to find out how effective the HPV vaccine is in these women, they add. © nec/aerzteblatt.de