Clinical value of serum cystatin C level in the screening, diagnosis and postoperative evaluation of patients with breast cancer

ObjectiveTo investigate the expression levels of cystatin C(Cys C) in serum and cancerous tissue of patients with breast cancer, and its clinical value in the screening, diagnosis and disease evaluation of patients with breast cancer.

MethodsFifty-three patients with primary breast cancer, 48 patients with benign breast tumor and 40 healthy females were divided into the breast cancer group, benign group and control group, respectively.For the three groups, the serum Cys C levels were detected using latex enhances transmission immunity turbidimetry, and the diagnostic efficacy(including sensitivity, specificity, and accuracy rating) of serum Cys C in breast cancer were evaluated using ROC curve.The expression levels of Cys C protein in breast benign tumor tissues, breast cancerous tissues and para-cancerous tissues were detected using Western blotting.

ResultsThe serum level of Cys C in breast cancer group was significantly higher than that in control group and benign group(P < 0.01), and the level of Cys C in benign group was higher than that in control group(P < 0.01).The serum level of Cys C in breast cancer patients after operation was lower than that before operation(P < 0.01).When the Cys C≤1.015 mg/L was negative, and Cys C>1.015 mg/L was positive, the sensitivity, specificity and accuracy of Cys C in diagnosing breast cancer were 67.92%, 80.00% and 73.12%, respectively.The serum levels of Cys C in breast cancer patients with age >50 years old, tumor size ≥2 cm, infiltrating ductal carcinoma, lymph node metastasis and clinical classification for Ⅲ type were higher than those in breast cancer patients with age ≤50 years old, tumor size < 2 cm, infiltrating lobular carcinoma, no lymph node metastasis and clinical classification for Ⅰ-Ⅱ type, respectively, and the differences of which were statistically significant(P < 0.01).The results of Western blotting showed that the expression level of Cys C protein in breast cancer tissues was lower than that in para-cancerous tissues, and the expression level of Cys C protein in para-cancerous tissues was higher than that in benign breast tissues(P < 0.01).

ConclusionsDetecting the serum level of Cys C has good sensitivity, specificity and accuracy in clinical screening and diagnosis of breast cancer.The heterogeneity of Cys C expression in cancer tissues and serum may be closely related to its role in breast cancer progression.