London School of Hygiene & Tropical Medicine

Testing women to see if they are cured of the virus that can cause cervical cancer following treatment for abnormal cells on the surface of the cervix is more effective and cheaper than cervical screening alone, according to research led by the London School of Hygiene & Tropical Medicine.

In England, cervical screening through cytology is recommended every three years for women aged 25-49 and every five years for women aged 50-65 years.

Cervical intraepithelial neoplasia or CIN are pre-cancerous lesions on the surface of the cervix that can develop into cervical cancer if left untreated. After treatment for high grade CIN, guidelines in the UK previously recommended annual cytology for at least 10 years. After low grade CIN, cytology is recommended at six, 12 and 24 months, and if all results are negative then women can resume routine screening.

Previous studies were inconsistent about whether or not testing for the human papillomavirus (HPV) as “test of cure” was more effective or cost-effective than cytology testing alone.

In the study published in the BMJ today, researchers from the School and collaborators including Cancer Council, NSW conclude that testing for HPV is more effective and less costly than the annual cytology follow-up over 10 years. HPV testing performed six months after treatment effectively “distinguishes women at future risk of serious recurrent cervical disease and supports the full scale implementation of HPV testing as a test of cure after treatment of CIN”. They add, however, that there is a need for ongoing monitoring and evaluation of the long term safety of these strategies

Analysing data (comprising 416 women) from six sites across England that returned women to routine screening after a single negative HPV test result at six months, they found that that follow-up after treatment for CIN by cytology only resulted in 29 reoccurring cases of CIN stage 3 per 1,000 women over 10 years. The HPV ‘test for cure’ averted around eight additional cases over this time. The cytology only follow-up estimated cost is £358,222 per 1,000 women with HPV ‘test of cure’ costing £348,834, saving approximately £9,388 per 1000 women treated.

According to the authors, early use of HPV testing after treatment averts more cases of CIN stage 3 and is cost-saving because it is more effective at early detection of women who are at risk of recurrent disease in future. They add that HPV testing results in fewer colposcopies (a detailed examination of the cervix) over 10 years than cytology only follow-up, and a higher proportion of colposcopies resulted in re-treatment - an important reduction in the burden of follow-up on women, and also on the health system.

Dr Rosa Legood, Lecturer in Decision Modelling at the London School of Hygiene & Tropical Medicine, who led the research in collaboration with modellers in Australia, said: "The key finding from our research is that human papillomavirus (HPV) testing is likely to be more effective and cost less than strategies based on annual cytological follow-up of women treated for pre-cancer lesions.

“I am pleased that this research has led to the NHS changing its policy for how women are managed following treatment of abnormal cells as the evidence shows this approach is better for patients and also saves money."

• R.Legood et al, Cost-effectiveness of HPV test of cure following treatment for cervical intraepithelial neoplasia in England: Results from the NHS Sentinel Sites Study. BMJ 2012; 345;e7086, doi: 10.1136/bmj.e7086