This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Cancers of the cervix (the neck of the womb) are nearly always caused by human papillomavirus (HPV). New research suggests that women who test positive for HPV could benefit from more frequent screening for cervical cancer.
Researchers analysed data from 72,000 women in 2 separate studies. The women had been screened for cervical cancer and followed up for up to 30 years. The studies found that the risk of cervical cancer is still apparent 30 years after a positive HPV test. By contrast, women who tested negative for HPV had a low risk of developing cervical cancer.
The findings suggest that women with HPV, who have a raised risk of cervical cancer, could benefit from more frequent screening, the researchers say. Women who do not have HPV and are at low risk, could be screened less often. The findings could influence how the national cervical screening programme is delivered.
Different methods of testing for cervical cancer and HPV were used in the 2 studies. The researchers found that the newer tests (similar to those currently used by the NHS) detected precancer sooner and were better able to predict future risk of cervical cancer than previous methods.
Policymakers involved in cervical screening will be interested in this research. The findings also highlight for women and clinicians the need for regular cervical screening for women who test positive for HPV.
What’s the issue?
Most HPV infections clear without treatment within 2 years. But some infections remain for a lifetime and can cause genital warts or cervical cancer. Almost 3,000 women in the UK are diagnosed with cervical cancer each year, and most are under 45 years.
Cervical cancer develops from abnormal changes in cells that line the cervix (precancer). Diagnoses of, and deaths from, cervical cancer in the UK have fallen over the last 30 years. This is due to the NHS’s screening programme, which was set up in 1988.
The ARTISTIC trial compared the screening test used by the NHS at the time (liquid-based cytology) with HPV testing. Women aged 20 – 64 years from Greater Manchester took part between 2001 – 2003 and have been followed up since (the ARTISTIC group).
Data from the ARTISTIC trial was compared to that from an older study (the Manchester study) which involved women from a similar location some years previously (1987 – 1992). This was around the time the NHS screening programme started. Women were invited for a Pap smear (in which cells from the cervix are examined under a microscope) every 3 – 5 years.
This analysis examined how many women from the 2 studies (ARTISTIC and Manchester) went on to develop cervical cancer. It compared the different approaches to screening.
Researchers analysed data on 48,000 women in the Manchester group and 25,000 in the ARTISTIC group. They were all followed up until 2020.
Over 30 years, 1,152 women in the Manchester group developed precancer, and 144 developed cervical cancer. Over 17 years, 427 women in the ARTISTIC group developed pre-cancer and 32 developed cervical cancer.
The researchers found that the risk of developing cervical cancer:
- increased over time in both studies after a single positive HPV test, (in the Manchester group, 0.7% at 5 years, 1.7% at 15 years, and 2.5% at 30 years; the same pattern occurred in the ARTISTIC group, but the risk was approximately halved)
- was low, particularly among older women, after a negative test for HPV (0.1% of women in the Manchester group at 30 years; 0.04% of women in the ARTISTIC group over 15 years).
The newer screening test used in the ARTISTIC study (liquid based cytology) detected pre-cancer much sooner than the Pap smears used in the Manchester Cohort. The newer HPV test used in the ARTISTIC study was more accurate and better predicted the future risk of cervical cancer compared with the older HPV tests used in the Manchester study.
Why is this important?
The increased risk of cervical cancer following HPV infection persisted for up to 30 years in this study. By contrast, women who did not have HPV had a low risk of developing cervical cancer.
The researchers suggest that women with a positive HPV test are screened for cervical cancer until they test negative. Discontinuing screening before then may not be safe, they say, even if women are older than 65 (the upper age of women in the cervical screening programme). These women could benefit from more frequent screening, they say.
The results support less frequent testing for women with a low risk of cervical cancer (who do not have HPV), the authors say.
The results also confirm that the newer tests for cervical cancer and HPV now being used in the NHS screening programme are more sensitive than previous methods. The researchers say this contributed to the lower rates of cervical cancer and precancer in the ARTISTIC group.
The data from the ARTISTIC trial helped the NHS to decide to switch to HPV testing in 2019. The researchers are still using the follow-up data to answer questions which will allow further improvements to the screening programme. In particular, they will explore how to manage testing for women (aged 60-64) who have a positive HPV result on their last test.
You may be interested to read
This Alert is based on: Gilham C, and others. Long-term risks of invasive cervical cancer following HPV infection: follow-up of two screening cohorts in Manchester. British Journal of Cancer 2023; 128: 1933 – 40.
A short podcast about the study from the International Papillomavirus Society.
Information about screening from Jo’s Cervical Cancer Trust.
Information on taking part in NIHR studies regarding cervical cancer.
Funding: this study was partly funded by the NIHR Health and Technology Assessment programme.
Conflicts of Interest: none declared.
Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.