Abstract
BACKGROUND: The principal cause of cervical cancer is sustained high-risk human papillomavirus (HPV) infection. However, some cases remain unrelated to HPV infections. Current HPV screening methods have difficulties identifying HPV-negative patients and implementing them in low-resource settings. Therefore, it is important to explore easily accessible and low-cost biomarkers to optimize the current cervical cancer screening strategies. METHODS: This cross-sectional study included 6998 women from the US National Health and Nutrition Examination Survey (NHANES), among whom 147 had self-reported cervical cancer. Serum γ - Glutamyltransferase (GGT) was employed as a continuous variable (naturally logarithmically transformed) and a categorical variable (≥50 U/L versus <50 U/L), and multivariate logistic regression models were utilized to progressively adjust for demographic features, sexual history, and clinical behaviors. The restricted cubic spline approach was adopted to further explore the dose-response relationship between GGT levels and cervical cancer to depict the potential nonlinear trends between them in a more elaborate manner. We also conducted subgroup and sensitivity analyses to ensure reliability of our results. This included multiple imputation of missing data and adjustment for crucial covariates, such as body mass index (BMI) and tobacco exposure, to comprehensively evaluate the impact of different factors on the outcomes. Ultimately, through mediation analysis, we probed the mediating function of tobacco exposure in the association between GGT levels and cervical cancer, aiming to obtain a more profound understanding of the underlying mechanisms of this health-related relationship. RESULTS: Serum GGT levels are positively correlated with cervical cancer risk. For each log unit increase in GGT levels, there was a 31% increased risk of cervical cancer (OR = 1.31, 95%CI: 1.01-1.70, P = 0.041) in the model adjusted for multiple risk factors. When the GGT level reached or exceeded 50 U/L, the risk increased by 76% (OR = 1.76, 95%CI: 1.04-2.98, P = 0.034). This tendency was consistent across several crucial subgroups, particularly among HPV-negative women (OR = 1.36, 95%CI: 1.01-1.84), suggesting that GGT may have some significance in different populations. The results of the sensitivity analyses demonstrated that the main findings remained robust, even when multiple imputations were employed to handle missing data. Nevertheless, the significant association between GGT and cervical cancer weakened when tobacco exposure was further adjusted, indicating that tobacco use might be involved. Mediation analysis further showed that the overall impact of GGT on cervical cancer was statistically significant (β = 0.0014; 95%CI: 0.0001-0.0020; P = 0.046), and approximately 18.15% of the impact was accounted for by tobacco exposure (ACME: β = 0.0003, 95%CI: 0.0001-0.0004, P < 0.001), suggesting a partial mediating role. CONCLUSION: Elevated serum GGT levels are associated with a heightened risk of cervical cancer even in HPV-negative patients. Although this association is partly mediated by tobacco exposure, GGT may still play a role in cervical cancer via nontobacco routes. The potential application of GGT as an auxiliary biomarker requires further validation in prospective studies.