Association between A Body Shape Index (ABSI) and lung cancer risk among never-smoking women in Northern China: a population-based prospective cohort study

Abdominal obesity, particularly visceral fat accumulation, increases the risk of lung cancer. As a novel anthropometric metric, A Body Shape Index (ABSI) offers improved quantification of abdominal obesity. This study aimed to investigate the association between ABSI and lung cancer risk among never-smoking women in Northern China. This study included never-smoking women from the Hebei Lung Cancer Screening Cohort (2016–2024). Multivariable logistic regression and restricted cubic splines (RCS) were used to evaluate the association between ABSI and lung cancer risk and characterize the dose–response relationship. Receiver operating characteristic (ROC) curve analysis was used to assess the discriminative ability of ABSI. Subgroup analyses were performed to identify high-risk populations and examine potential interaction effects, and sensitivity analyses were conducted to assess the robustness of the results. A total of 148,395 never-smoking women were included in this study, with 632 incident lung cancer cases diagnosed during the study period. After adjusting for covariates, higher ABSI quartiles were significantly associated with increased lung cancer risk (Q1 as reference; Q3: OR = 1.31, 95% CI: 1.05–1.65; Q4: OR = 1.32, 95% CI: 1.05–1.65; P for trend = 0.004). RCS analysis showed a significant overall association between ABSI and lung cancer risk ( P -overall = 0.018), while the test for nonlinearity was not statistically significant ( P -nonlinear = 0.054). Subgroup analyses identified a significant interaction by age ( P -interaction = 0.001), with a stronger positive association observed among women aged < 60 years (OR = 1.48, 95% CI: 1.05–2.08, P = 0.027). ROC curve analysis demonstrated that ABSI outperformed other conventional anthropometric measures in discriminating lung cancer risk, with the highest area under the curve (AUC) of 0.624 (95% CI: 0.602–0.645, P = 0.032). Elevated ABSI was significantly associated with increased lung cancer risk among never-smoking women, especially those aged < 60 years. Compared with conventional anthropometric measures, ABSI achieved the highest discriminative performance, although its overall discriminative ability was modest.