A new protocol for the analysis of self-collected cervical samples could reduce the need for follow-up clinician screening for many women, and result in more rapid referral for gynaecology assessment for others. This could improve cervical cancer screening procedures in the NHS.
Queen Mary researchers led a team which accessed data about each self-sample to estimate the risk of significant disease being present. This process could reduce the number of women recalled for clinician-collected sampling unnecessarily and allow others to be referred directly to secondary care.
Cervical cancer is one of the most preventable types of cancer. However, data show that uptake of in-person screening offered through the NHS Cervical Screening Programme is at an all-time low. Self-sampling HPV tests that allow an individual to collect their own sample for cervical screening, rather than go into a clinic, are being explored as a way to increase uptake in screening.
Recent research from Queen Mary found that almost 70% of women would choose to self-sample if offered the choice. The UK National Screening Committee is consulting on offering the option of human papillomavirus (HPV) self-sampling to under-screened people in the NHS cervical cancer screening programme. Unlike clinician-collected samples, which are typically taken during a GP visit, these self-samples can be taken at home but are not able to be processed using cytology. This means that a second, clinician-collected sample is required if HPV is found. This second sample is used to determine whether the patient needs immediate colposcopy, re-testing in 12 months, or whether the patient is already clear of the virus. Given that 1 in 5 women with an HPV positive self-sample do not attend for clinician-sampling, this could lead to cervical pre-cancer going untreated.
A research team led by Professor Peter Sasieni and published today in PLOSMedicine accessed details of the HPV test results of each self-sample that are not usually available for analysis. Using these data, the researchers, including Dr Jiayao Lei from the Karolinska Institute in Sweden, were able to divide HPV-positive women into three groups: high-risk, medium-risk, and low-risk. Only 5% of women in the study fell into the high-risk group, but about 40% of this group had disease that required treating; they would be recommended for an immediate colposcopy. 53% of women testing positive fell into the low-risk group and it was found that only 4% of them were found to have high-grade disease in the study. It is suggested that this low-risk group could safely be re-tested after 12 months without the need for immediate clinician-sampling.
Peter Sasieni, Professor of Cancer Epidemiology, Centre Co-Lead for the Centre for Cancer Screening, Prevention and Early Diagnosis in the Wolfson Institute of Population Health, said: ‘Based on our analysis, we were able to recommend that it would be safe for the majority of women who had initially tested positive in their self-sample to be re-tested after 12 months, rather than have to have a further clinician-sampled screening test. This assessment of risk would reduce the numbers called unnecessarily for these clinician-based screening while still catching the vast majority of instances of cancer in their early stages. Seeing as, some 20% of those under-screened still do not attend after a positive self-sample, this approach may be safer as well as being more acceptable.’
This study received funding from Cancer Research UK.
Jiayao Lei, Kate Cuschieri, Hasit Patel, Alexandra Lawrence, Katie Deats, YouScreen trial team, Peter Sasieni, Anita Lim. Human papillomavirus genotype and cycle threshold value from self-samples and risk of high-grade cervical lesions: a post-hoc analysis of a modified stepped-wedge implementation feasibility trial. PLOS MEDICINE 12 December 2024. https://doi.org/10.1371/journal.pmed.1004494
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