Correlates of circulating C-reactive protein and serum amyloid A concentrations in breast cancer survivors

Introduction Inflammatory status may be an important prognostic factor for breast cancer. Correlates of markers of inflammation in breast cancer survivors have not been thoroughly evaluated. Methods Using data from, the Health, Eating, Activity, and Lifestyle (HEAL) Study (a population-based, multiethnic prospective cohort study of female breast cancer patients) we evaluated the associations between circulating markers of inflammation (C-reactive protein [CRP] and serum amyloid A [SAA], measured ∼31 months after diagnosis) and several demographic, lifestyle, and clinical characteristics in 741 disease-free breast cancer survivors. Analysis of variance and regression methods were used for statistical analyses of log-transformed values of CRP and SAA. Results After adjusting for age, BMI, ethnicity, and study site, higher concentrations of CRP were associated with increasing concentration of SAA (P-trend < 0.0001), increasing age (P-trend < 0.0001), increasing BMI (P-trend < 0.0001), increasing waist circumference (P-trend < 0.0001), positive history of heart failure (P = 0.0007), decreasing physical activity (P-trend = 0.005), Hispanic ethnicity (P = 0.05 vs. non-Hispanic white), and current smoking (P = 0.03 vs. never smoking). Vitamin E supplementation (P = 0.0005), tamoxifen use (P = 0.008), and radiation treatment (compared to no chemotherapy or radiation; P = 0.04) were associated with reduced CRP. Associations of CRP with clinical characteristics were not significant in the adjusted models. In a multivariate analysis, CRP showed significant associations with waist circumference, BMI, age, history of heart failure, tamoxifen use, and vitamin E supplementation (R2 = 0.35). Similar, yet fewer, associations were observed for SAA (R2 = 0.19). Conclusions This study highlights important correlates of inflammatory status in breast cancer patients. Our results are consistent with those from similar studies of healthy women.