The histological grading had a significant correlation with the expression of ER (p<0.01, r = - 0.43), PR (p<0.001, r = - 0.4), HER2 (p<0.01, r = 0.35) and elevated serum levels of CA 15 - 3 (p<0.05, r = 0.25) in invasive breast carcinoma.