Cervical Screening Programme

NHS Cervical Screening Programme (NHSCSP)

Effect

Public Health England estimates that cervical screening in the UK saes up to 5,000 lives a year.
National target for cervical screening coverage is 80%.

Population

Routine cervical screening from 24.5 years to 64 years 
Age 25–49 years — screening every 3 years
Age 50–64 years — screening every 5 years

The role of HPV in cervical cancer

High-Risk subtypes of HPV (HR-HPV) is found in 99.7% of cervical cancer cases.
HR-HPV types 16 and 18 causes 70% of cervical cancer.

Cervical intraepithelial neoplasia (CIN)

Cervical intraepithelial neoplasia (CIN) is a premalignant lesion, detected by colposcopy.

CIN1 — basal one-third of the surface layer of the cervix is affected.

CIN2 — basal and middle two-thirds of the surface layer of the cervix is affected.

CIN3 — basal, middle, upper layers are affected.
Known as high-grade or severe dysplasia or stage 0 cervical carcinoma in situ. 

Left untreated, CIN2 or CIN3 (collectively referred to as CIN2+) may progress to cervical cancer. 
Women who have been treated for CIN are 2–5 times more likely than the general population to develop cervical cancer.
Several case series demonstrate that over 50% of cancers develop in women who are lost to follow up.

Classification of cervical cytology results

Inadequate
Negative — no abnormality is detected
Abnormal 
Borderline changes in squamous or endocervical cells
Low-grade dyskaryosis
High-grade dyskaryosis (moderate or severe)
Invasive squamous cell carcinoma
Glandular neoplasia

Obtaining a cytology sample for cervical screening

  1. Visualize the cervix (using a speculum)
    If the cervix appears abnormal, suggesting malignancy, arrange 2ww gynaecology referral 

  2. Take a sample from the whole of the transformation zone.

  3. Most cervical pre-cancer and cancer develops in the squamo-columnar junction

Primary HR-HPV testing (to be implemented in 2019)

In 2016, the UK National Screening Committee recommended that the HPV test should be used as the first (primary) test in cervical screening.
Cervical cytology will be used as a triage test for HR-HPV positive samples

HR-HPV Test Negative
Primary HR-HPV testing has a higher sensitivity (Low FN rate, High NPV) for high-grade CIN than primary cytology
Around 85-90% of women will test negative for HR-HPV.
A HR-HPV Test Negative test rules out CIN 2+ disease in 99.8% of cases.

HR-HPV Test Positive
Cervical cytology will be used as a triage test for HR-HPV positive samples.

Special Groups

Avoid cervical screening if:
menstruating
pregnant, <12 weeks postnatal, post-termination or post-miscarriage
genital tract infection

Pregnancy and cervical screening
If it is routine screening, reschedule to at least 3 months post-partum.
If indicated (previous test was abnormal) then seek specialist advice (colposcopy or HPV testing)

Women 65 years of age or older are invited if: 
A recent cervical cytology sample is abnormal.
They have not had a cervical screening test since 50 years of age and they request one.

Women with cervical stenosis OR a cervix that cannot be visualized
Refer for colposcopy

Unscheduled cervical screening 

Cervical screening is recommended in women who are immunosuppressed:

  • With kidney failure who require dialysis 

  • Who are about to undergo organ transplantation within a year before transplantation.

  • Who are starting cytotoxic drugs for rheumatological disorders 

  • Who are HIV positive at diagnosis and annually thereafter

Managing abnormal cervical smears (cervical cytology)

Borderline change or low-grade dyskaryosis—> HPV tested—>
if HPV negative —> Return to routine 3-5yr screening
if HPV positive —> Colposcopy <6 weeks

High-grade dyskaryosis (moderate or severe) OR Suspected invasive cancer or glandular neoplasia —> HPV testing not required —> Colposcopy <2 weeks

Inadequate cervical cytology sample —>. Repeat cervical cytology >3 months

If three consecutive inadequate cervical cytology samples —> Colposcopy <6 weeks

Follow up after CIN excision (Test of cure protocol)

  1. Repeat cervical cytology 6 months after CIN excision treatment (test of cure).

  2. Cervical cytology results
    Negative, borderline or low-grade AND negative HR-HPV —> repeat cytology in 3 years
    Negative, borderline or low-grade AND positive HR-HPV —> refer colposcopy
    High-grade dyskaryosis or invasive squamous carcinoma —> refer colposcopy

Managing women presenting with symptoms suggestive of suspected cervical cancer

Symptoms and Signs
Post-coital bleeding
Intermenstrual bleeding
Abnormal cervical appearance

Action
URGENT 2 week wait referral for colposcopies and examination to rule out malignancy
Cervical screening should never be used as a diagnostic tool (even if a smear is overdue).
If abnormalities are ruled out following colposcopy assessment, woman is returned back to the screening programme

Managing abnormal cervical smears (cervical cytology)

Borderline change or low-grade dyskaryosis—> HPV tested—>
if HPV negative —> Return to routine 3-5yr screening
if HPV positive —> Colposcopy <6 weeks

High-grade dyskaryosis (moderate or severe) OR Suspected invasive cancer or glandular neoplasia —> HPV testing not required —> Colposcopy <2 weeks

Inadequate cervical cytology sample —>. Repeat cervical cytology >3 months

If three consecutive inadequate cervical cytology samples —> Colposcopy <6 weeksP

Organisms reported on their cervical cytology result

Treat infections such as Candida, bacterial vaginosis, Trichomonas vaginalis, herpes simplex virus (HSV)

If actinomyces-like organisms (ALOs) are present:

Determine if woman is symptomatic of ALO: pelvic pain, deep dyspareunia, intermenstrual bleeding, vaginal discharge, dysuria, or significant pelvic tenderness

If asymptomatic and ALO on cervical smear: No need to remove intrauterine device (IUD) or levonorgestrel intrauterine system (LNG-IUS). No follow up is required.

If symptomatic and ALO on cervical smear: Consider removing IUD or LNG-IUS  AND  obtain endocervical swabs for Chlamydia trachomatis and Neisseria gonorrhoeae. 

Dr Rajesh Varma