Background: The majority of death-related ovarian cancer is epithelial ovarian cancer (EOC). Regarding the Federation of Gynecology and Obstetrics (FIGO) stage IV EOC, the 5-year overall survival (OS) has not changed in last decades. Platelet (PLT) count and CA125 level are both prognostic markers that related to inflammation and immune evasion in EOC. This study intended to assess the prognostic value of pretreatment PLT count and CA125 level in FIGO stage IV EOC.
Methods: The study included 108 patients diagnosed with FIGO stage IV EOC and treated with surgery and/or chemotherapy between January 1995 and December 2016. The PLT counts and CA125 levels of the patients before any treatment were analysed with clinical and pathological parameters, OS and progression-free survival (PFS). The survival of different groups was analyzed using the Kaplan-Meier method. The PLT-CA125 scores (0, 1, and 2) were defined basing on the presence of thrombocytosis (PLT count > 400,000/μL), an elevated CA125 level (CA125 > 1200 U/mL), or both. The prognostic value of PLT-CA125 was assessed with a Cox regression model.
Results: Median OS, but not median PFS, was significantly decreased in patients with thrombocytosis or elevated CA125 levels when compared with the others (p = 0.011 & p = 0.004). The median OS was significantly decreased in patients with a PLT-CA125 score of 2 [37.8 months; 95% confidence interval (CI) 20.6-54.9] compared with patients with a PLT-CA125 score of 0 (70.0 moths, 95% CI 38.0-101.9, p < 0.001). The median PFS was also significantly decreased in patients with a PLT-CA125 score of 2 (19.6 months; 95% CI 13.0-26.3) compared with patients with a PLT-CA125 score of 0 (32.0 months; 95% CI 23.3-40.7, p = 0.011). Furthermore, multivariate analysis identified both PLT-CA125 scores of 2 and 1 as independent poor prognostic factors for OS (p = 0.004 & p < 0.001) and PFS (p = 0.033 & p = 0.017) compared with a PLT-CA125 score of 0.
Conclusions: The pretreatment PLT-CA125 score can be a reliable marker with high accessibility for stratifying prognosis in patients with FIGO stage IV EOC.
Keywords: CA125; Epithelial ovarian cancer; Immune evasion; Inflammation; Prognosis; Thrombocytosis.