Exposure to polycyclic aromatic hydrocarbons promotes the progression of low‐grade cervical intraepithelial neoplasia: A population‐based cohort study in China

Abstract Low‐grade cervical intraepithelial neoplasia (CIN1) is an early stage of cervical cancer development. Previously, we reported that exposure to polycyclic aromatic hydrocarbons (PAHs) increases the risk of cervical precancerous lesions, especially in females with a high‐risk human papillomavirus (HR‐HPV) infection. However, the effects of PAHs on CIN1 progression remain unclear. A community‐based prospective cohort study was conducted to evaluate the role of exposure to PAHs in the progression of CIN1. A total of 564 patients diagnosed with CIN1 were followed‐up at 6, 12, and 24 months, post‐diagnosis, to determine CIN1 reversion, persistence, and progression. Exposure to PAHs was determined by the urine 1‐hydroxipayrene (1‐OHP) level. Our results showed that the 1‐OHP level was significantly higher in patients with CIN1 persistence/progression than in those with reversion ( P < .05). High exposure to PAHs increased the risk of CIN1 persistence/progression, with hazard ratios (HR), 95% confidence intervals (CI) of (1.62, 1.24–2.67), (1.98, 1.42–2.75), and (2.37, 1.61–3.49) at 6, 12, and 24 months, post‐diagnosis, respectively. The effect was enhanced with HR‐HPV positivity, as determined at 6 (1.82, 1.24–2.67), 12 (3.02, 1.74–5.23), and 24 (2.51, 1.48–4.26) months, post‐diagnosis. Moreover, the predictive value of exposure to PAHs for CIN1 persistence/progression was higher in HR‐HPV‐positive patients than in HR‐HPV‐negative patients. The results revealed that exposure to PAHs facilitated the malignant progression of CIN1 and hindered its reversal, particularly in patients with HR‐HPV infection. Our findings provide novel insights into early prevention and intervention targeting the initiation and progression of cervical neoplasia.