Abstract
<title>Abstract</title> <p> Background Cervical cancer remains an important public health problem among women worldwide. Although several demographic, reproductive, lifestyle, and clinical characteristics have been associated with cervical cancer, population-based evidence from Iran remains limited. This study aimed to investigate factors associated with cervical cancer in a population-based case–control study conducted in northeastern Iran. Methods This population-based retrospective case–control study included women covered by Mashhad University of Medical Sciences between March 21, 2017, and March 19, 2021. Cases comprised 74 women with histopathologically confirmed cervical cancer identified from the regional Population-Based Cancer Registry, while 148 controls without cervical cancer were randomly selected from the Primary Health Care Family Physician Information System. Univariable and multivariable logistic regression analyses were performed to estimate crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs). Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), Hosmer–Lemeshow goodness-of-fit test, Brier score, and Nagelkerke R². Internal validation was performed using bootstrap resampling. Results A total of 222 women (74 cases and 148 controls) were included in the analysis. After adjustment for potential confounders, increasing age (adjusted OR [aOR] = 1.043, 95% CI: 1.004–1.083; <italic>P</italic> = 0.030) and earlier age at first pregnancy (aOR = 0.918 per one-year increase in age at first pregnancy, 95% CI: 0.850–0.992; <italic>P</italic> = 0.030) were independently associated with cervical cancer. No independent associations were observed for body mass index, parity, age at menarche, smoking, or hypertension. The final multivariable model demonstrated modest discriminatory ability (AUC = 0.666, 95% CI: 0.586–0.746), satisfactory calibration (Hosmer–Lemeshow <italic>P</italic> = 0.847), a Brier score of 0.218, and a Nagelkerke R² of 0.100. Bootstrap internal validation demonstrated stable model performance (mean bootstrap AUC = 0.640; SD = 0.023). Conclusions Increasing age and earlier age at first pregnancy were independently associated with cervical cancer among women in northeastern Iran. Although the predictive performance of the model was modest, the findings provide population-based evidence that may contribute to cervical cancer risk assessment and targeted prevention strategies. Future prospective studies incorporating additional demographic, reproductive, behavioral, and socioeconomic factors are warranted to improve cervical cancer risk prediction. </p>