Purpose: To evaluate the prognostic value of pretreatment plasma systemic immune-inflammation index (SII), albumin, and fibrinogen levels in metastatic castration-resistant prostate cancer (mCRPC) patients treated with first-line docetaxel and to screen out the patients with the greatest risk for poor prognosis.
Methods: The plasma SII, albumin, and fibrinogen levels were examined before treatment and analyzed with patient clinicopathological parameters and overall survival (OS). The survival analysis was performed using the Kaplan-Meier method, and prognostic factors were assessed using the Cox proportional hazard regression model.
Results: The incidences of elevated SII level, hypoproteinemia, and hyperfibrinogenemia were 52.51%, 25.14%, and 27.93%, respectively. SII level was associated with neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) (P < 0.001). Albumin level was found closely correlated with ECOG PS (P = 0.006), PLR (P = 0.042), and hemoglobin (P = 0.009), but not other parameters. Elevated plasma fibrinogen level was significantly associated with Eastern Cooperative Oncology Group performance status (ECOG PS) (P = 0.009), visceral metastases (P < 0.001), and PLR (P = 0.001). In multivariate Cox regression model, visceral metastases SII (HR 2.133, 95% CI 1.163-3.913; P = 0.014), albumin (HR 0.540, 95% CI 0.307-0.949; P = 0.032), and fibrinogen (HR 1.888, 95% CI 1.069-3.335; P = 0.029) were further confirmed to be the independent prognostic factors for OS. Of the three target parameters, we found that patients with none abnormalities of the three parameters showed the best prognosis, and patients with at least any two abnormalities of them showed markedly worse prognosis than patients with any one abnormalities of the three parameters (P < 0.001).
Conclusions: Pretreatment SII, albumin, and fibrinogen are independent prognostic factors in mCRPC patients treated with first-line docetaxel. Moreover, the combined use of SII, albumin, and fibrinogen levels may help us to identify the high-risk populations for treatment decisions.
Keywords: CRPC; D-dimer; Fibrinogen; Prognosis; SII.