Women with abnormal cervical screening but without visible lesions, particularly those with a type 3 transformation zone (TZ3), present a clinical challenge due to the non-visible squamocolumnar junction, increasing the risk of missed high-grade lesions. There is currently no consensus on optimal follow-up strategies for this group. This study aims to evaluate a risk-based management approach for these patients.
A cross-sectional study analyzed data from 4,648 women with TZ3 who underwent colposcopy and endocervical curettage (ECC) with or without cervical biopsies at Hunan Provincial Maternal and Child Health Care Hospital (2021–2024). Logistic regression with restricted cubic splines analyzed demographic, cytological and HPV data to identify HSIL+ predictors and age-risk thresholds.
Among the study population, 3.1% (145 cases) of HSIL+ were identified despite negative colposcopy, although additional undetected cases may exist. Women with high-grade cytology (ASC-H/HSIL/AGC) had a consistently high HSIL+ risk (32.5%–37.2%) across all HPV subgroups. In low-grade cytology (NILM/ASCUS/LSIL), HPV 16/18 positivity increased HSIL+ risk (2.4%–5.0%) compared to non-HPV 16/18 cases (1.6%–1.8%), with the highest rate observed in LSIL cases (5.0%). In women with low-grade cytology and non-HPV 16/18 positivity, age and HSIL+ risk showed a nonlinear relationship (RCS P-nonlinear = 0.008). Threshold analysis identified 55 years as a critical cutoff, with a 10% annual increase in HSIL+ risk for women ≥ 55. (OR = 1.10, 95% CI [1.02–1.19]; P = 0.015). Further age-stratified analysis in this subgroup showed a clear upward trend: HSIL+ detection rates were 4.42% in women aged ≥ 65.
Among women with abnormal cervical screening and no visible lesions at type 3 transformation zone, HSIL+ risk varies by cytology, HPV genotype, and age. Our findings suggest that immediate diagnostic evaluation is warranted for those with high-grade cytology, HPV 16/18 with LSIL, and women aged ≥ 65 years with low-grade cytology and non-16/18 HPV, as their HSIL+ risk exceeds the 4% threshold recommended by current US guidelines. Conversely, women under 65 with low-grade cytology and non-16/18 HPV, or those with NILM/ASCUS and HPV 16/18, may be appropriate candidates for conservative follow-up. These results support a more tailored, risk-based approach to management in this challenging population.