ERBB2 and breast cancer: In the BC group, MDA showed a moderate positive correlation with CA-19.9 (r = 0.440, P = .005) and a strong negative correlation with the presence of ER (r = −0.588, P < .001), as well as a strong positive correlation with IMA (r = 0.590, P < .001) and with the presence of HER2 (r = 0.627, P < .001).