Predictive value of systematic immune-inflammation index combined with Ki-67 index on prognosis of prostate cancer patients after laparoscopic radical prostatectomy

Abstract

Background: Prostate cancer (PCa) presents a wide spectrum. Systemic immune-inflammation index (SII) and Ki-67 index are new biomarkers that can predict prognosis in different types of cancer. We explored the predictive value of their combination on the prognosis of PCa patients after laparoscopic radical prostatectomy (LRP).

Methods: In this retrospective study, 290 patients who underwent LRP at Nanjing Lishui People's Hospital between January 2016 and February 2021 were enrolled. They were divided into the good prognosis group (N = 235) and poor prognosis group (N = 55) based on the follow-up results. Both the baseline data and postoperative pathological results were collected. The Ki-67 index was determined using immunohistochemical kits, and the patients were allocated to the SII/Ki-67 index high/low expression groups according to the cut-off values to further analyze their relationship with clinical/pathological data of PCa patients. Logistics multivariate regression analysis was utilized to analyze the independent factors affecting post-LRP prognosis of CPa patients. ROC curve was plotted to assess the predictive value for post-LRP prognosis, and Kaplan-Meier curve/Log-rank were used for analysis.

Results: Significant differences were found in PSA/Gleason score/T stage/lymph node metastasis/seminal vesicle invasion/neutrophils/lymphocytes/platelets/preoperative SII/Ki-67 index between the good/poor prognosis groups. Preoperative SII/Ki-67 were related to PSA/lymphocytes/platelets in PCa. Seminal vesicle invasion and preoperative SII + Ki-67 index were independent factors affecting post-LRP prognosis. Preoperative SII + Ki-67 index had a better predictive value than preoperative SII or Ki-67 index alone. Patients with high preoperative SII and Ki-67 index levels had an increased risk of poor prognosis after LRP.

Conclusion: Preoperative SII + Ki-67 index had a better predictive value for poor prognosis after LRP than SII or Ki-67 index alone.

Keywords: Ki-67 index; Laparoscopic radical prostatectomy; Prognosis; Prostate cancer; Systematic immune-inflammation index.