Prognostic value of C-reactive protein and platelet count in endometrial cancer: a retrospective cohort study

Pre-treatment thrombocytosis and elevated C-reactive protein have been linked to poor prognosis in endometrial cancer, although findings are inconsistent. We aimed to study the prognostic significance of C-reactive protein and platelet count in a contemporary single-center endometrial cancer cohort.

A retrospective study was conducted at a single tertiary referral center. We included consecutive patients with endometrial cancer who underwent staging surgery between January 2010 and December 2022. Pre-operative C-reactive protein and platelet counts were recorded. Receiver operating characteristic curve analysis and Kolmogorov-Smirnov statistics were applied. Kaplan-Meier curves and Cox regression were calculated for progression-free survival and overall survival.

Overall, 797 patients were included. The median age was 64 years (interquartile range [IQR]; 57-70), and the mean body mass index was 32.4 kg/m² (IQR 26.0-37.1). The median follow-up time was 53 months (IQR 31-75). Endometrioid carcinoma was the most common histologic sub-type, comprising 75.4% of cases (n = 601), including grade 1 (46.3%, n = 369), grade 2 (22.1%, n = 176), and grade 3 (7.0%, n = 56)]. The median age was 64 years, and 71% of patients had stage I disease. Thrombocytosis (platelet ≥400,000) was observed in 5.6% of patients, and the median C-reactive protein was 3.2 mg/L. Thrombocytopenia (platelet <150,000) occurred in 24 (3.0%) patients. Receiver operating characteristic analysis showed limited predictive performance for recurrence (area under the curve: 0.434 for platelet, 0.506 for C-reactive protein) and modest performance for death (area under the curve: 0.513 and 0.613, respectively). Using a C-reactive protein cutoff of 2.45 mg/L, patients with elevated C-reactive protein had significantly worse overall survival (p <.001). In multi-variable Cox analysis, C-reactive protein remained independently associated with overall survival (adjusted hazard ratio [HR] 2.37, 95% confidence interval [CI ] 1.23 to 4.55), along with age (HR 1.05, 95% CI 1.02 to 1.08), stage IV disease (HR 5.82, 95% CI 3.06 to 11.08), and P53 mutated (HR 2.69, 95% CI 1.06 to 6.79). Platelet was not prognostic.

Pre-treatment C-reactive protein is an independent predictor of survival in endometrial cancer, whereas platelet count shows limited prognostic relevance. C-reactive protein may serve as an accessible biomarker to refine risk stratification, particularly in low-resource settings where molecular profiling is not routinely available.