A cross-sectional study examining the relationship between the advanced lung cancer inflammation index and prostate cancer.

[BACKGROUND] Prostate cancer (PCa), a significant health concern among middle-aged and elderly men globally, has increasingly been associated with metabolic and inflammatory processes. The advanced lung cancer inflammation index (ALI), a novel marker reflecting nutritional and inflammatory status, has not yet been thoroughly investigated in the context of PCa. This study investigated the potential link between ALI and PCa.

[METHODS] We first conducted a cross-sectional study utilizing data from the National Health and Nutrition Examination Survey (NHANES). The relationship between ALI and PCa was examined by NHANES-provided survey weights. Smoothed curve fitting and threshold effect analyses were conducted to evaluate possible nonlinear associations. Then we analyzed the correlation between the prognosis of PCa patients and ALI.

[RESULTS] Out of 15,042 adult participants, 683 (4.54%) were diagnosed with PCa. The risk of PCa decreased across increasing quartiles of ALI. Multivariate logistic regression analysis revealed that compared to participants in the lowest ALI quartile (Q1: 2.89-41.94), those in higher quartiles (Q2: 41.94-59.08, Q3: 59.08-80.88, and Q4: ≥80.88) had progressively lower odds of developing PCa in both unadjusted and adjusted models. Smoothed curve fitting indicated a U-shaped relationship between ALI and PCa. Longitudinal follow-up data indicated that lower ALI values were positively correlated with a poor survival in cancer patients.

[CONCLUSION] Our study revealed a non-linear relationship between ALI and the risk of PCa development. Specifically, there was a negative correlation between ALI and PCa risk when the ALI value was < 100. Furthermore, we found that lower ALI levels are strongly associated with a poor survival in cancer patients. Additional large-scale prospective studies are needed to confirm these findings and investigate the underlying mechanisms.