Management of women with low grade cytology: how reassuring is a normal colposcopy examination?

Objectives To determine the rate of cervical intraepithelial neoplasia grade 2 ( CIN 2+) in women with low grade cervical cytology and a normal colposcopy examination over 3 years of follow‐up. Design Cohort study within a randomised controlled trial. Setting NHS Cervical Screening Programmes in G rampian, T ayside and N ottingham. Population Eight hundred and eighty‐four women aged 20–59 years with borderline nuclear abnormalities ( BNA ) or mild dyskaryosis with a normal and adequate colposcopy examination. Methods Samples at baseline were tested for 14 high‐risk (Hr) types using GP 5+6+ methodology and for HPV 16 and 18 using type‐specific primers. Women were followed up post‐colposcopy by cervical cytology at 6‐month intervals in primary care. After 3 years, women were invited for an exit colposcopy examination and underwent LLETZ if any colposcopic abnormality was identified. Main outcome measures Absolute and relative risks of CIN 2+ during follow‐up and/or at exit colposcopy. Results The median age was 36 years. The absolute risk of developing CIN 2+ within 3 years was 1.86 per 100 woman years and for CIN 3+, 0.64 per 100 woman years. One microinvasive cancer was identified. The relative risk ( RR ) was highest for women with initial mild dyskaryosis who were H r HPV ‐positive ( RR 5.86, 95% confidence interval 2.53–13.56) compared with women with BNA who were H r HPV ‐negative. Conclusion For women with low grade cervical cytology, the risk of a high grade CIN within 3 years of a normal colposcopy examination is low. Women can be reassured that, even with a positive HPV test, the risk of developing CIN 2 or worse is sufficiently low to return to the routine 3‐year recall.