Inflammation as a key mediator: linking triglyceride-glucose index to prognosis in non-muscle-invasive bladder cancer.

BACKGROUND

Bladder carcinoma (BCa) is a prevalent urological malignancy characterised by high recurrence and progression rates, posing significant challenges in clinical management. The triglyceride-glucose (TyG) index has emerged as a promising prognostic marker for metabolic health in various cancers. This study explores the prognostic value of the TyG index in non-muscle-invasive bladder cancer (NMIBC), with a focus on its association with high-grade recurrence-free survival (RFS) and progression-free survival (PFS) and the mediating role of systemic inflammation.

METHODS

A total of 230 patients diagnosed with NMIBC between October 2017 and October 2022 were included in this retrospective study. Clinical and pathological data were collected alongside follow-up treatment outcomes. Mediation analysis was conducted to quantify the role of systemic inflammation, using markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and interleukin-8 (IL-8), in the relationship between the TyG index and patient prognosis.

RESULTS

The TyG index was identified as a significant, non-linear prognostic factor for both RFS and PFS. An inverted U-shaped relationship was observed, with inflexion points at 9.186 and 9.168 for RFS and PFS, respectively. Below these thresholds, the TyG index was positively associated with worse outcomes (RFS: HR = 3.37, 95% CI = 1.77-6.41, < 0.001; PFS: HR = 3.54, 95% CI = 1.65-7.58, = 0.001). Mediation analysis revealed systemic inflammation as a critical intermediary, contributing significantly to the observed associations.

CONCLUSION

These findings suggest that the TyG index could serve as a valuable tool for risk stratification and prognostic assessment in NMIBC. Its integration into clinical decision-making frameworks may improve personalised management strategies, particularly by targeting systemic inflammation as a modifiable factor.