Systemic inflammation response index (SIRI) as a predictive factor for overall survival in advanced soft tissue sarcoma treated with eribulin

Eribulin is a tubulin and microtubule-targeting drug that has clinical benefit in overall survival (OS) for patients with advanced soft tissue sarcoma. Eribulin's efficacy has been confirmed in several clinical trials, although no clinically useful biomarkers have been identified. We therefore sought to clarify the predictive factor of eribulin treatment, while focusing on systemic inflammation and immune response values.This study included 33 advanced STS patients treated with eribulin between March 2016 and September 2019. We evaluated the associations of clinical factors influencing the efficacy of eribulin treatment and systemic inflammatory and immune response, including the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the lymphocyte-to-monocyte ratio (LMR), the systemic inflammation response index (SIRI), and the prognostic nutrition index (PNI), with progression-free survival (PFS) and OS using the Kaplan-Meier method and log-rank test.NLR, LMR, PLR, SIRI, and PNI were unassociated with PFS. Compared with patients with SIRI <1.5, those with an SIRI ≥1.5 had a significantly shorter OS [median OS 15 months (95% confidence interval [CI] 8-not reached) vs. 7 months (95% CI 3-14), P = 0.04]. Moreover, the PFS tended to be shorter for patients with SIRI ≥1.5 who received chemotherapy after eribulin treatment than in those with SIRI >1.5 [median PFS 92.5 days (95% CI 27-204) vs. 133 days (95% CI 36-507), P = 0.08].High SIRI values may predict poorer overall survival and the efficacy of subsequent drugs after eribulin treatment among patients with advanced soft tissue sarcoma.