Cervical Screening (HPV)

Public Health England Guidance NHS cervical screening (CSP) programme. Last updated: Jul 2025.

NICE CKS Cervical screening. Last revised: Sep 2025.

Article Last Updated:17/12/2025

A typo in the diagram has been fixed (hsHPV → hrHPV)

Date: 24/11/25

Background Information

HPV Testing Results

Cervical screening tests for 14 high-risk HPV types (including 16 and 18; the most carcinogenic ones)

Testing for HPV first is proven to be more sensitive than cytology.

Cytology Results

There are 3 possible cytology results:

Negative: no abnormality detected
Abnormal: the sample may show any of the following:
- Borderline changes in squamous or endocervical cells
- Low-grade dyskaryosis
- High-grade dyskaryosis (moderate)
- High-grade dyskaryosis (severe)
- Invasive squamous cell carcinoma
- Glandular neoplasia
Inadequate: possible reasons include
- Sample taken inappropriately
- Cervix not fully visualised
- Contains insufficient cells
- Contains obscuring element (e.g. lubricant, inflammation, blood)
- Incorrect labelling

Cytology can report dyskaryosis (cells with abnormal nuclei), but NOT cervical intraepithelial neoplasia (CIN).

CIN is strictly a histological diagnosis, made from a colposcopic biopsy or an excisional specimen. It assesses how much of the epithelial thickness is affected by abnormal cells.

Colposcopy

Involves direct visualisation of the cervix with a colposcope

Common techniques / procedures performed in colposcopy:

Application of acetic acid: stains abnormal tissue white (acetowhitening)
Application of iodine: stains normal tissue dark brown
Biopsy: to allow histological assessment

Guidelines

Target Population

Cervical screening target population:

25-64 y/o with a cervix regardless of gender identity
Invitation sent every 5 years (assuming -ve screening)

From 1st July 2025 onwards, invitation is sent every 5 years across all ages (25-64 y/o).

Previously, cervical screening was offered every 3 years in 25-49 y/o and every 5 years in 50-64 y/o.

NB People with a subtotal hysterectomy still have a cervix, thus still need to undergo cervical screening.

Only those with total/radical hysterectomy do not need to undergo cervical screening.

General Screening Algorithm (Most People)

Initial screening test: high-risk HPV (hrHPV) testing with reflex cytology (i.e. only perform cytology if hrHPV +ve, see below)

-ve hrHPV

Return to routine recall (i.e. screen after 5 years)

Exceptions include:

Test of cure pathway (post-CIN treatment): explained further down
Untreated CIN 1 pathway
- The untreated CIN 1 pathway is different because CIN 1 is a diagnosed lesion requiring its own structured follow-up, not a routine screening scenario
- Due to low risk of progression, CIN 1 can be managed conservatively (vs CIN ≥2, which is actively treated on diagnosis) with follow-up:
  - After diagnosis, ALL patients undergo repeat testing after 12 months, and further testing depending on results
  - Only after 2 consecutive negative HPV results do they return to routine ‘screening’ recall (i.e., 5 yrly)

+ve hrHPV

Perform cytology testing.

Abnormal Cytology Testing

Refer to colposcopy

-ve Cytology Testing

Repeat hrHPV testing at 12 months

hrHPV -ve → return to routine recall (every 5 years)

hrHPV +ve → cytology testing
- Abnormal cytology → colposcopy
- -ve cytology → repeat hrHPV after 12 months
  - hrHPV +ve (after 24 months) → colposcopy
  - hrHPV -ve → return to routine recall (every 5 years)

To understand the interpretation and subsequent action from another angle, we are trying to stratify the patients into either 1) return to routine recall or 2) colposcopy

hrHPV +ve alone is not an indication for colposcopy → do cytology first

Whenever there is abnormal cytology → straight to colposcopy
If there is hrHPV +ve but -ve cytology → repeat hrHPV (this is the 2nd time)
- If hrHPV becomes -ve → routine recall
- Again, following the above principle: if hrHPV +ve → do cytology, and if cytology abnormal → colposcopy
- But if cytology -ve for 2 times, and hrHPV still +ve (this is the 3rd time) → colposcopy

Important: if cytology has been -ve, but hrHPV is still +ve at the 3rd time, colposcopy is necessary regardless of cytology results.

Unavailable HPV test / Inadequate Sample for Cytology

If this happens at any point → repeat the test after 3 months (no less than 3 months)

If still unavailable (HPV) results / inadequate cytology (that is, ≥2 consecutive times) → refer to colposcopy

Screening in Certain Populations

Reasons To Delay Screening

If any of the following:

Menstruating
<12 weeks postpartum
<12 weeks after termination of pregnancy / miscarriage
Currently pregnant
Has vaginal discharge / pelvic infection

Screening During Pregnancy

Defer the test until at least 3 months postpartum

If previous cytology screening was abnormal and in the interim the person becomes pregnant:

DO NOT delay colposcopy (can be done in the late 1st / early 2nd trimester)
Only consider delaying assessment until after delivery if there are low-grade changes

Screening in Immunosuppressed Patients

HIV +ve patients → offer screening at diagnosis, then yearly screening (instead of 5 yearly)

Other immunosuppressed patients require screening at or near diagnosis/treatment, however, don’t need more frequent cervical screening:

Kidney failure patients who require dialysis → offer screening at or after diagnosis (if not up to date)
Any other disease with high chance of needing organ transplantation → offer screening at or after diagnosis (if not up to date)
Those about to undergo organ transplantation → offer screening within 1 year before transplantation
Those who take cytotoxic drugs for rheumatological disorders → offer cervical screen at the start of treatment (if screening history is incomplete)

Post-CIN Treatment

Perform test of cure (hrHPV test) 6 months after treatment:

If hrHPV -ve → repeat cytology in 3 years
If cytology -ve (after 3 years) → return to routine recall (i.e., 5 yearly testing)

If at any point hrHPV or cytology is +ve / abnormal → refer for colposcopy