Cervical Screening and Colposcopy

Overview

Cervical Screening and Colposcopy is the national programme for the early detection and treatment of pre-cancerous cervical cell changes (cervical intraepithelial neoplasia — CIN) before they have the opportunity to progress to invasive cervical cancer. The NHS Cervical Screening Programme uses primary HPV testing — women who test positive for one of 14 high-risk HPV subtypes have cervical cytology assessed for abnormal cell changes and are referred for colposcopy if high-grade changes are detected. Colposcopy is a clinic-based examination using a magnifying colposcope and acetic acid to identify and precisely biopsy abnormal transformation zone areas. High-grade CIN 2 and CIN 3 are treated in the outpatient setting by LLETZ under local anaesthetic.

Types of Cervical Screening and Colposcopy

• Primary HPV testing — testing cervical samples for 14 high-risk HPV subtypes as the primary cervical screening modality every 5 years from age 25
• Colposcopy with targeted punch biopsy — magnified assessment of the transformation zone with direct biopsy of the most abnormal acetowhite area
• LLETZ (large loop excision of the transformation zone) — outpatient excisional treatment under local cervical anaesthesia removing the entire transformation zone
• Colposcopy see-and-treat — same-appointment LLETZ treatment when colposcopic findings are clearly high-grade without awaiting biopsy results
• LLETZ or NETZ under general anaesthesia — for women where outpatient treatment is not feasible due to severe anxiety or technical difficulty

Risk Factors of Cervical Screening and Colposcopy

• Persistent high-risk HPV infection — particularly HPV 16 and HPV 18 — driving the cervical cellular transformation leading to CIN and cancer
• Smoking — tobacco carcinogens in cervical mucus significantly impairing local HPV clearance and increasing CIN progression risk
• Immunosuppression from HIV infection, organ transplantation, or long-term immunosuppressive medication impairs HPV clearance
• High number of lifetime sexual partners increasing cumulative exposure risk to multiple high-risk HPV subtypes
• Early age at first sexual intercourse exposing the biologically vulnerable immature cervical transformation zone to HPV infection
• Non-attendance at regular cervical screening — the majority of cervical cancer deaths in the UK occur in under-screened women

Symptoms of Cervical Screening and Colposcopy

• Post-coital bleeding — vaginal bleeding after sexual intercourse — the most clinically significant symptom of cervical pathology requiring urgent colposcopy
• Intermenstrual vaginal bleeding occurring between clearly defined regular menstrual periods requiring cervical assessment
• Post-menopausal vaginal bleeding associated with cervical lesion or cervical cancer requiring urgent 2-week wait referral
• Offensive or blood-stained watery vaginal discharge persistent beyond a normal infective cause suggesting cervical malignancy
• Visible lesion, ulceration, or irregular growth on the cervix identified at routine speculum examination
• Pelvic pain and deep dyspareunia in locally advanced cervical cancer invading the parametria and pelvic side wall
• Urinary symptoms including haematuria, frequency, and difficulty voiding from bladder involvement by locally advanced cervical cancer
• No symptoms in the majority of women with CIN — emphasising the absolute importance of regular cervical screening attendance