Risk factors for the onset of cervical intraepithelial neoplasia

BACKGROUND: Persistent human papillomavirus (HPV) infection is a well-established cause of cervical intraepithelial neoplasia (CIN). Epidemiological studies show that while HPV infection is common, it is far more prevalent than CIN itself. Consequently, HPV testing exhibits moderate specificity and positive predictive value for detecting high-grade CIN. Currently, there is no optimal strategy for identifying HPV-positive women at high risk of CIN.

AIM: This study aims to assess the socioeconomic, behavioral, and comorbidity factors associated with an increased risk of developing cervical intraepithelial neoplasia.

MATERIAL AND METHODS: The study included 121 women who presented to the Medical Research and Education Center of Moscow State University in the period from 2022 to 2023. Pap-smear revealed normal data in 66 women (Group 1, NILM), mild cervical intraepithelial neoplasia in 27 (Group 2, LSIL), and severe cervical intraepithelial neoplasia in 28 (Group 3, HSIL). A comparative analysis of clinical data and medical history, data of liquid cytology and HPV typing was performed in all patients. Statistical analysis was performed using the MedCalc software package.

RESULTS: The analysis showed that the risk of severe cervical intraepithelial neoplasia increased 5.4-fold in patients aged >30 years, 3.4-fold in smokers, 9.9-fold in patients who had been sexually active for more than 10 years, 6.3-fold in patients who had ≥4 sexual partners, 4.1-fold in patients who used withdrawal method of contraception (coitus interruptus), 7.0-fold in patients who had ≥3 pregnancies, 4.7-fold in patients with HPV infection (in particular, 4.3-fold in women infected with HPV 16). Patients with cervical intraepithelial neoplasia had significantly greater probability to be infected with high-risk HPV types (88.9% in patients with LSIL and 85.7% in patients with HSIL vs. 56.1% in NILM women), in particular, HPV 16 was detected in more than half of patients with HSIL.

CONCLUSION: In this study sample, the risk of cervical intraepithelial neoplasia was associated with age over 30 years, smoking, duration of the sexual activity >10 years, number of sexual partners (>4), lack of barrier contraception, number of past pregnancies (>3), and persisting high-risk HPV infection, especially HPV 16.