CEACAM5 and breast cancer: Concerning the differentiation between breast cancer patients and healthy women, the markers RNA quantity (AUC 0.665; 95% CI 0.546–0.783), miR-34a (AUC 0.722; 0.608–0.836), CEA (AUC 0.717; 0.601–0.833) and CA 15-3 (AUC 0.721; 0.605–0.837) showed good diagnostic performance.