Cervical Screening
Public Health England Guidance NHS cervical screening (CSP) programme. Last updated: Jul 2025. NICE CKS Cervical screening. Last revised: Sep 2022.
Background Information
In the context of cervical screening, testing 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 first.
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
Involves direct visualisation of the cervix with a colposcope
Common process / procedures performed in colposcopy:
Common process / procedures performed in colposcopy:
- Application of acetic acid: stains abnormal tissue white (acetowhitening)
- Application of iodine: stains normal tissue drak-brown
- Biopsy: to allow histological assessment
Guidelines
25-64 y/o women and those with a cervix.
Invitation sent every 5 years (assuming -ve screening).
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 is offered every 3 years in 25-49 y/o and every 5 years in 50-64 y/o.
NB those that underwent subtotal hysterectomy still has a cervix, thus still need to undergo cervical screening.
Only those who underwent total / radical hysterectomy do not need to undergo cervical screening.
Initial screenign test: high-risk HPV (hrHPV) testing with reflex cytology (i.e. only perform cytology if hrHPV +ve, see below)
Return to routine recall (i.e. screen after 5 years)
Exceptions include:
Exceptions include:
- Test of cure pathway (post-CIN treatment)
- Untreated CIN 1 pathway
Perform cytology testing.
Refer to colposcopy
Repeat hsHPV testing at 12 months
- hsHPV -ve → return to routine recall (every 5 years)
- hsHPV +ve → cytology testing
- Abnormal cytology → colposcopy
- -ve cytology → repeat hsHPV after 12 months
- hsHPV +ve (after 24 months) → colposcopy
- hsHPV -ve → return to routine recall (every 5 years)
To understand the interpretation and subsequent action in another angle: we are trying to straitfy the patinets into either 1) return to routine recall or 2) colposcopy
- hsHPV +ve alone is not an indication for colposcopy → do cytology first
- Whever there is abnormal cytology → straight to colposcopy
- If there is hsHPV +ve but -ve cytology → repeat hsHPV
- If hsHPV becomes -ve → routine recall
- Again following the above principle: if hsHPV +ve → do cytology, and if cytology abnormal → colposcoy
- But if cytology -ve for 2 times, and hsHPV still +ve → colposcopy
If this happens at any point → repeat the test after 3 months (no less than 3 months)
If still unavailable (HPV) or inadequate (cytology) → refer to colposcopy
If still unavailable (HPV) or inadequate (cytology) → refer to colposcopy
If any of the following:
- Menstruating
- <12 weeks post-partum
- <12 weeks ater termination of pregnancy / miscarriage
- Currently pregnant
- Has vaginal discharge / pelvic infection
Defer the test until at least 3 months post-partum
If previous screening was abnormal and in the interim the person becomes pregnant:
If previous screening was abnormal and in the interim the person becomes pregnant:
- DO NOT delay colposcopy
- Only consider delaying assessment until after delivery if there is low-grade changes
The important ones are HIV +ve patients → offer screening at diagnosis then yearly screening (instead of 5 years)
Other patients don't need more frequent cervical screening:
Otherwise, no indications for increased surveillance.
Other patients don't need more frequent cervical screening:
- Kidney failure who require dialysis → offer screening at or after diagnsois (if not up to date)
- Any other disease with high chance of needing organ transplantation → offer screening at or after diagnsois (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)
Otherwise, no indications for increased surveillance.
Perform test of cure (hsHPV test) 6 months after treatment:
If at any point hsHPV or cytology is +ve / abnormal → refer for colposcopy
- If hsHPV -ve → repeat cytology in 3 years
- If cytology -ve (after 3 years) → return to routine recall (back to hrHPV first testing)
If at any point hsHPV or cytology is +ve / abnormal → refer for colposcopy
Simplied Flow Chart
