Impact of thyroid-stimulating hormone ratio change on the progression-free survival of patients receiving gemcitabine, cisplatin, and durvalumab therapy for advanced biliary tract cancer.

[PURPOSE] To investigate the independent predictors of progression-free survival (PFS) after gemcitabine, cisplatin, and durvalumab (GCD) therapy for advanced biliary tract cancer (BTC), including the thyroid-stimulating hormone (TSH) ratio pre- and post-GCD.

[METHODS] The subjects of this retrospective analysis were 29 patients receiving GCD for advanced BTC. The cutoff TSH ratios were determined by a receiver operating characteristic (ROC) curve for PFS. The independent predictors of PFS after GCD were determined by univariate and multivariate analyses.

[RESULTS] The median PFS was 4.9 (range, 0.9-16.8) months. The objective response and disease control rates were 13.0% and 52.2%, respectively. The cutoff values of the TSH ratio after one and two cycles were 0.97 [area under the ROC curve (AUROC): 0.86, 95% confidence interval (CI): 0.70-1.00], p = 0.02] and 1.2 (AUROC: 0.820, 95% CI: 0.664-0.976), respectively. Multivariate analysis identified pretreatment neutrophil-to-lymphocyte ratio (NLR) ≥ 5 [hazard ratio (HR): 6.27, 95% CI: 1.83-21.5, p = 0.004] and TSH ratio after two cycles of < 1.2 (HR: 3.25, 95% CI: 1.25-8.46, p = 0.02) as independent predictors of PFS.

[CONCLUSION] The TSH ratio after two GCD cycles of < 1.2 and a pretreatment NLR ≥ 5 are potential prognostic factors for poor PFS.