Prognostic impact of interleukin‑6 and C‑reactive protein on patients with breast cancer

The prognostic impacts of preoperative C-reactive protein (CRP) and interleukin (IL)-6 expression levels in patients with breast cancer remain controversial. A total of 55 female patients with invasive breast cancer were enrolled, and preoperative prognostic parameters including IL-6 and CRP were analyzed. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method, and candidates' prognostic factors were examined using a Cox proportional hazard model. Using receiver operating characteristic curve analysis, IL-6 at 10.0 pg/ml and CRP at 0.12 mg/dl were determined as threshold values to predict OS and RFS, respectively. Patients with IL-6 10.0 pg/ml had poorer OS compared with those with IL-6 <10.0 pg/ml (P=0.003), and patients with CRP 0.12 mg/dl had poorer RFS compared with those with CRP <0.12 mg/dl (P<0.001). Serum IL-6 level (hazard ratio, 13.230; 95% confidence interval, 1.285-136.214; P=0.030) and triple-negative subtype (hazard ratio, 11.739; 95% confidence interval, 1.415-97.362; P=0.023) were independent prognostic factors for OS, and CRP expression level was an independent prognostic factor for RFS in patients with breast cancer (hazard ratio, 18.571; 95% confidence interval, 2.240-153.949; P=0.007). In patients with invasive breast cancer, preoperative serum IL-6 and triple-negative subtype may be independent prognostic factors for OS, while for RFS, preoperative CRP may be a more accurate prognostic factor compared with those currently established.