Clinical significance of preoperative C-reactive protein and squamous cell carcinoma antigen levels in patients with penile squamous cell carcinoma

Objective: To evaluate the relevance of C-reactive protein (CRP) and squamous cell carcinoma antigen (SCC-Ag) levels in relation to clinicopathological factors and prognosis in penile cancer.

Patients and methods: A total of 124 Chinese patients with penile squamous cell carcinoma (SCC), treated between November 2007 and October 2014, were analysed retrospectively. Receiver-operating characteristic curves were used to identify the combination of markers with the best sensitivity and specificity for prognosis prediction. Statistical data analysis was performed using a non-parametric method, and survival analysis was performed using the log-rank test and Cox proportional hazard model.

Results: Levels of CRP ≥4.5 mg/L and SCC-Ag ≥1.4 ng/mL were both significantly associated with lymph node metastasis (LNM) laterality (chi-squared trend test, P = 0.041), extranodal extension (chi-squared trend test, P < 0.001), pelvic LNM (chi-squared trend test, P = 0.024), pathological tumour status (chi-squared trend test, P = 0.002), pathological nodal status (chi-squared trend test, P < 0.001), and disease-specific survival (DSS; log-rank test, P < 0.001). Moreover, the influence of CRP and SCC-Ag levels on DSS (P = 0.033, hazard ratio 3.390, 95% confidence interval 1.104-10.411) remained after adjusting for smoking history, phimosis, tumour status, tumour cell differentiation and nodal status.

Conclusions: The present study shows that the combined measurement of preoperative CRP and SCC-Ag levels may serve as an independent biomarker for LNM, advanced tumour stage and DSS in patients with penile SCC.