Predictive and Prognostic Role of Systemic Immune-Inflammation Index (SII) in Metastatic Colorectal Cancer Patients Treated with Trifluridine/Tipiracil.

Abstract

In advanced-stage colorectal cancer (CRC), a strategy based on a sequence of systemic therapies brings survival benefits in most patients. Trifluridine and tipiracil hydrochloride (TT) is a chemotherapy drug effective in patients in the third- or later line setting. No highly specific biomarkers have been established for TT therapy so far. However, a systemic immune-inflammation index (SII), which is based on platelet, neutrophil and lymphocyte counts is applied to predict prognosis. In this retrospective, multicenter study, clinical data on 179 metastatic CRC patients treated with TT were collected. To evaluate factors predicting TT therapy response and overall survival, univariate logistic regression analysis was conducted. Subsequently, factors with p < 0.05 in univariate analysis were included in multivariate analysis. In the multivariate analysis of progression-free survival (PFS), three favorable parameters were significant: good to moderate histological differentiation (p = 0.0038), carcinoembryonic antigen (CEA) < 5 ng/L (p = 0.0316) and SII ≤ 550 (p = 0.007). Favorable prognostic factors revealed in the multivariate analysis of overall survival (OS) were: <3 prior lines of treatment (p = 0.02), good to moderate histological differentiation (p = 0.0003), CEA < 5 ng/L (p = 0.0227) and SII ≤ 550 (p = 0.0001). Our study indicated that pre-treatment SII may be clinically useful for selecting likely responder patients and assessing the prognosis for mCRC patients treated with TT.