Printed on: September 19th, 2025

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Cervical cancer screening and HPV testing

Cervical cancer screening and HPV testing

Cervical cancer is currently the fourth commonest cancer in women globally. Since the cervical screening programme was introduced in the UK, the incidence of cervical cancer has fallen by 44% and the number of deaths from the disease by 70%.

The discovery of human papillomavirus (HPV) DNA in cervical cancer cells led to the understanding that persistent cervical infection with certain ‘high-risk’ HPV types is a significant cause of cervical cancer (BMJ 2013;347:f4781).

Two techniques have subsequently been developed to reduce the cervical cancer burden even further:

• HPV testing.
• HPV vaccination (see article on HPV vaccination).

This article was updated in July 2025.

• Genital HPV infection.
• Early age of first coitus.
• Multiple sexual partners.
• Lower socioeconomic status.
• Smoking.
• Combined oral contraceptive use.

Age, number of sexual partners and socioeconomic status are all associated with risk of contracting HPV. Smoking and combined hormonal contraception use probably increase risk by reducing the capacity to clear the infection.

HPV infection is common in young, sexually active women; around 40% of 20–24-year-old women are HPV positive. Infection declines with age, probably as a result of clearance and reduced reinfection (Br J Cancer 2009;101:511).

Most infections are harmless and short-lived, but some persist and lead to CIN and invasive cervical cancer. HPV 16 and 18 are the most important and contribute to 70% of cancers worldwide. There are 11 other high-risk types (BMJ 2013;347:f4781) which, together with 16 and 18, account for 99% of cervical cancer.

Following a recommendation from the National Screening Committee, the interval for screening invitations was changed from 1 July 2025 (UK National Screening Committee guidance):

• Women and people with a cervix will be eligible for screening:
  • At age 25y (or up to 6m before).
  • Every 5 years from age 25–64y ONLY after negative screening for HPV.
  • Annually for those living with HIV.
  • ≥65y: only if a recent screening test was abnormal.
• Those with positive HPV testing will be offered earlier follow-up screening or colposcopy, based on risk assessment (outlined below).

This change will be rolled out after the next scheduled screening date for each woman:

• Women already scheduled for 3-year follow-up based on testing prior to 1 July 2025 will still be invited for screening at 3 years.
• Women with a negative HPV test after 1 July 2025 but positive screening in the past 5 years will still be invited for a further test at 3 years initially; they will then move to 5-year testing if that is negative.

Prior to 1 July 2025, all women aged 25–49y were offered screening every 3 years, but this was changed due to the strong evidence in favour of HPV-negative tests as a predictor of very low risk of cervical cancer.

• The change made to the screening interval for younger women in England was a move towards risk-stratified screening. It brought alignment with the existing guidance for Scotland and Wales, and brought the screening interval for people in England aged 25–49y in line with previous protocols for those aged 50–64y.
• We should offer screening to any trans men who still have a cervix (see below). 

From 2019, the following system was implemented in England, Scotland and Wales:

• All cervical samples are initially tested for HPV.
• HPV-positive samples will have reflex cytological testing (using same liquid-based cellular sample). 
• HPV-positive women with abnormal cytology results will be referred to colposcopy.
• Women who have negative cytology will then be recalled at 12m (in anticipation that at least half will then be HPV negative).
• HPV-positive/cytology-negative women who then test negatively for HPV will have a ‘safety check’ HPV test at 3y, before returning to usual recall.
• Persistently HPV-positive women will be referred to colposcopy, regardless of cytology result.

The cervical screening algorithm is shown below:

(gov.uk – cervical screening care pathway)

Evidence for the safety of longer screening intervals with HPV-based screening comes from the POBASCAM trial. This was a huge RCT in the Netherlands that compared cytology-based cervical cancer screening (controls) with cytology and HPV co-testing-based screening (intervention). The routine screening interval in both groups was 5y, and follow-up data is now available for three rounds of screening. Women with moderate dyskaryosis or worse were referred directly for colposcopy. Women with borderline or mild dyskaryosis, or positive HPV results, had follow-up testing at 6 and 18m (BMJ 2016;355:i4924). The RCT found that:

• For women with negative cytology but a positive HPV test, cervical cancer incidence was significantly lower in the intervention group (55.4/100 000 woman years) compared with the control group (190.9/100 000 women years, rate ratio 0.29 (CI 0.1–0.87, P = 0.02). This supports the role of HPV testing in identifying a group of women at risk of cervical cancer that would not be picked up by cytology alone.
• There was no significant difference in cumulative incidence of cervical cancer or CIN 3 after three rounds of HPV-negative screening compared with two rounds of cytology-negative screening. This suggests that a negative HPV test provides longer reassurance than a negative cytology test.
• HPV-positive, cytology-negative women remained at significantly increased risk of CIN 3+ throughout follow-up compared with HPV-negative women, e.g. HPV-positive women with negative baseline and repeat cytology had an 18.5-fold (CI 12.5–27.3) increase in CIN 3+ compared with HPV-negative women. This supports a risk stratification approach for future screening intervals based on the HPV result.
• The women in the trial were all aged over 29y at entry, so it does not provide information about HPV screening in younger women.

Real-world data from the English HPV screening pilot provided evidence to support extension of screening intervals as follows (BMJ 2022;376:e068776):

• 5 years in women aged 25–49y after a negative HPV test.
• Longer in women aged ≥50y after a negative HPV test.

This applies whether DNA or mRNA HPV test assays are used.

In 2009, following public pressure to reduce the initial screening age to 20y, the Advisory Committee on Cervical Screening conducted a review. It concluded:

• There was no evidence that cancer cases had increased in women <25y (and it is rare in this age group).
• There was good evidence that screening <25y was ineffective and potentially may do more harm than good.

Women aged over 50y are now higher risk for cervical cancer than younger women who have been vaccinated against HPV, and yet, in the UK, a quarter of women this age do not attend for screening (BJGP 2022;72(725):e873).

With rates of cervical cancer in this age group predicted to rise by over 60% in the next 20 years, it is important to address this issue. A small, UK-based, qualitative study asked women why screening declines in this age group:

• Decreased frequency of screening invitation was interpreted as an indicator of reduced risk.
• Women >45y are more likely to cite past traumatic experiences of intimate medical examinations as a reason for non-attendance.
• Ageing/menopause can make screening both more painful and more embarrassing for women.
• Lack of time to prioritise their own health due to wider family priorities.
• Lack of a relationship with a medical practitioner to explore their concerns/barriers to attendance.

• Willingness to ask non-attendees what the barrier to screening is.
  • Women reported a lack of curiosity from clinicians.
• Active problem-solving to address concerns or difficulties.
• Age-relevant information about sexual health and the need for screening.
• Continuity of care (the authors acknowledge the huge challenge this presents!).

• Almost all cervical cancers are caused by HPV (the wart virus).
• Many types of HPV are completely harmless, but there are 13 ‘high-risk’ types of virus (including 16 and 18) which together are responsible for >99% of cervical cancer. 
• The National Cervical Cancer Screening Programme tests for these high-risk subtypes, and women with a positive result have an increased risk of cervical abnormalities that may progress to cervical cancer.
• Women with a negative test result have a low risk of developing cervical cancer, so can safely return to the normal screening programme.
• Most sexually active women come into contact with HPV at some time in their life. It can be spread by any close sexual contact, not just penetrative sex, and the use of condoms provides only limited protection.
• There is nothing you can prescribe to ‘cure’ the infection. In most cases, the woman’s immune system will clear the infection within 1–2y.

• Cervical smear (cytology) results report the level of dyskaryosis (abnormalities seen within the cervical cells).
• Dyskaryosis may be reported as borderline, mild, moderate or severe.
• Moderate or severe dyskaryosis may also be referred to as ‘high-grade dysplasia’ and mild dyskaryosis as ‘low-grade dysplasia’.
• CIN (cervical intraepithelial neoplasia) reflects the degree of invasion of the abnormal cells, and the extent can only be determined at biopsy (taken at colposcopy).
• CIN 1 is a one-third depth invasion; CIN 3 is full thickness invasion.
• The level of dyskaryosis is suggestive, but not indicative, of the level of CIN that will be found at colposcopy, e.g. it is possible to have moderate dyskaryosis and CIN 3.

Almost 23 000 women in the UK are treated for precancerous changes of the cervix picked up by cervical screening each year (BMJ 2023;383:p2802).

Most will be offered surgical treatment with a loop excision under local anaesthetic via colposcopy clinic (a LLETZ procedure), but other treatment modalities include cone excision using laser or cold knife (which may be done under general anaesthetic), laser ablation and cryotherapy.

Immediate complications are generally mild. The RCOG leaflet includes the following advice on risks of a loop excision (Large loop excision of the transformation zone (LLETZ) | RCOG):

• Pain and discomfort: 67% of people will experience pain for up to 4 weeks, similar to a mild period pain.
• Bleeding: 85% of people will bleed for between 4 days and 2 weeks. This is often worse around day 10 as the scab at the treatment site heals. If bleeding through a pad in <1h, call for urgent advice.
• Infection: up to 14% of people will get an infection after the procedure. If vaginal discharge is offensive or yellow/green in colour, seek advice.
• Changes to vaginal discharge: 65% of people will experience changes in vaginal discharge.
• Premature birth or late miscarriage: 2% of people will suffer premature birth or late miscarriage after a loop excision, and this risk is higher after more invasive treatment options.
• Cervical stenosis: 2–14% of women will develop cervical stenosis. This is more likely in postmenopausal women or those who have had more than one treatment.

An NIHR alert published in the BMJ compared treatment options and their risks of future preterm delivery, alongside rates of recurrence of the precancerous changes (BMJ 2023;383:p2808).

Treatment with loop excision was shown to offer the best balance between risk of future preterm delivery and risk of recurrence of precancerous changes. The authors hope this study will allow women and caregivers to make informed decisions about treatment choice for precancerous cervical changes picked up on cervical screening.

There are significant differences in uptake of cervical screening associated with social deprivation (OHID data 2021/22). The gap in uptake between the least and most economically deprived groups is:

• 11% at age 25–49y.
• 8% at age 50–64y.

Around 500 cases of cervical cancer each year in the UK are linked with deprivation (CRUK accessed 2025).

There are ethnic disparities in uptake of screening and cervical cancer outcomes, with (Health equity evidence centre, 2024) :

• Asian women having a 32% lower uptake of cervical screening than White women.
• Higher mortality rates for Black African women (4.9 per 100 000 cases per year) compared with White women (2.7 per 100 000 cases per year).

The Health Equity Evidence Centre (HEEC) reviewed the evidence on what strategies can be used to address inequalities in cervical cancer screening (Health Equity Evidence Centre - what works: addressing inequalities in the uptake of cervical screening). Using a combination of strategies was seen to improve outcomes:

Especially beneficial for ethnic minority groups if recruited from within the local community, support workers may offer education, appointment booking and reminder calls.

Culturally relevant information and educational material improves screening uptake when provided by support workers.

Invitations and reminders for cervical screening were more effective if sent from the patient's own practice (Cochrane 2021, CD0002834). The HEEC also found that reminders with direct booking links showed improved response rates.

In June 2025, as part of publicity around the NHS 10-year plan, the government announced the introduction of ‘home HPV testing kits’ for cervical screening, to be offered to women who have not responded to invitations for cervical screening. The full details of who will be eligible for the scheme have not yet been announced (June 2025) (gov.uk - home testing kits for lifesaving checks against cervical cancer).

Research has shown that self-sampling for HPV significantly improves screening uptake in lower socioeconomic and immigrant groups (Prev Med 2018;111:323, Cancer Causes Control 2018;29:793, PloSOne 2023;18:e0281976).

A meta-analysis published in the BMJ showed that self-taken samples for HPV (using brushes, swabs or tampons and a polymerase chain reaction analysis technique) are as sensitive and only slightly less specific than samples taken by clinicians (BMJ 2019;364:l361).

Although not covered in the HEEC review, non-speculum sampling has also been recommended as an approach to improve cervical screening uptake. This method tests for HPV on cervical cells shed through the lower genital tract, through either a clinician-taken vaginal swab (without a speculum) or a first pass urine sample (BJGP 2022;72(721):e538).

• A small cross-sectional study of patients attending colposcopy with known HPV or CIN2+ looked at the sensitivity and specificity of non-speculum clinician-taken samples compared with conventional sampling.
  • Sensitivity at detecting CIN2+ was 83.3% with 100% specificity compared with speculum sampling.
  • Sensitivity at detecting HPV was 96.6% with specificity of 96.4% compared with speculum sampling.
  • 71% of women preferred non-speculum sampling for their next cervical screening.
• A non-speculum smear taken by a clinician may be a suitable alternative to self-sampling, and trials are underway (YouScreen, HPValidate, and ACES studies) to validate this approach (BJGP 2022;378:e070135).

After colposcopy treatment for CIN, women in the UK Screening Programme are offered a repeat test of HPV status to assess whether they have cleared the virus, and to stratify their ongoing risk of cervical cancer.

There is emerging evidence from systematic reviews that vaccination against HPV at the time of treatment for high-grade CIN might reduce the risk of recurrence of local preinvasive disease (BMJ 2022;378:e070135). You can find more detail on this evidence in our article on HPV vaccination.

• Their risk is very low.
• 99% of cervical cancers are caused by HPV infection.
• They are still eligible for cervical screening but may choose to decline.
• Women who have been sexually active at any time carry some risk.

A literature review commissioned by the NHS Cervical Cancer Screening Programme in 2009 found that:

• Uptake of cervical screening is up to 10× lower in this group.
• Prevalence of HPV among lesbian and bisexual women is 3–30%.
• Prevalence of HPV among lesbian women who report never having heterosexual intercourse is 19%.
• HPV can be transmitted through lesbian sexual contact.
• 30% of lesbian women had been told by their GP they did not need a smear test.

We should encourage lesbian and bisexual women to participate in screening and vaccination in the same way as heterosexual women.

Transgender men who still have a cervix should be encouraged to have a cervical smear, especially if they have had previously abnormal results.

If they are registered with their GP as male, they will not routinely be invited but can be offered screening by liaising with the national screening team.

Some practical points:

• If they have used testosterone, they may find the procedure uncomfortable.
• We should be aware that we may need to use a small speculum to obtain the sample.

Trans women who are registered as female will obviously not need a smear. With the agreement of the patient, the screening service should be informed in order to avoid inappropriate invitation.

	Cervical cancer screening All women in the UK aged 25–64y are offered routine cervical screening. More than 99% of cervical cancer is due to high-risk HPV infection. Under-25-year-olds are not offered screening because research has shown that it is not effective in this age group, and the harms outweigh the benefits. From 2019, the National Cervical Screening Programme in the UK changed from primary cytology to primary HPV testing. With primary HPV testing: Cytology is only performed on HPV-positive samples. Women with abnormal cytology are then referred for colposcopy. Women with HPV-positive/negative cytology have continued annual HPV monitoring. HPV ‘test of cure’ is part of follow-up for all women who have colposcopy treatment, and determines future screening interval and whether further colposcopy is needed. There is strong evidence for less frequent screens using HPV testing, including personalised recall based on HPV vaccination history. Lesbian and bisexual women should be encouraged to attend screening because they are at risk of HPV infection; their attendance is typically 10× lower than other women. Trans men will not be invited if registered as male. If they have not had surgery, they should be offered a smear. Self-testing may be introduced to improve uptake of cervical screening.
	Reflective exercise: How would you explain to a woman what being HPV positive means? How could you encourage lesbian and bisexual women to attend? Do you currently give them the correct information?
	Useful resources: Websites (all resources are hyperlinked for ease of use in Red Whale Knowledge) Cancer Research UK - cervical cancer screening (more information about HPV triage and what the results mean) LGBT Health - smear leaflet (specific information leaflet for lesbian and bisexual women) gov.uk - assessment of young women aged 20–24 with abnormal vaginal bleeding RCOG – large loop excision of the transformation zone (LLETZ) (patient information on colposcopy)