血清胱抑素C检测在乳腺癌筛查、诊断及术后评估中的临床价值

目的探讨胱抑素C（Cys C）在乳腺癌病人血清和癌组织中的表达水平，以及在乳腺癌筛查、诊断及病情评估中的临床应用价值。方法选取原发性乳腺癌病人53例作为乳腺癌组，同期住院治疗的乳腺良性肿瘤病人48例为良性病组，另选同期体检的健康女性40名为对照组，应用胶乳增强透射免疫比浊法检测各组血清Cys C水平，用受试者工作特征曲线评估血清Cys C检测对乳腺癌的诊断效能（灵敏度，特异性与准确度）；Western blotting法检测乳腺良性肿瘤、乳腺癌组织与癌旁正常组织（对照组织）Cys C蛋白表达状况。结果血清Cys C含量乳腺癌组高于对照组和良性病组，良性病组高于对照组（P < 0.01），手术治疗后乳腺癌病人血清Cys C水平较术前未治疗时降低（P < 0.01）。Cys C≤1.015 mg/L为阴性，Cys C>1.015 mg/L为阳性，其诊断乳腺癌的敏感度为67.92%，特异性为80.00%，准确度73.12%。年龄>50岁、肿瘤大小≥2 cm、浸润型导管癌、有淋巴结转移、临床分型为Ⅲ型的乳腺癌病人血清Cys C含量分别高于年龄≤50岁、肿瘤大小 < 2 cm、浸润型小叶癌、无淋巴结转移、临床分型为Ⅰ~Ⅱ型的病人，差异均有统计学意义（P < 0.01）。Cys C蛋白在乳腺癌组织表达低于癌旁组织，癌旁组织表达高于乳腺良性肿瘤组织（P < 0.01）。结论血清Cys C检测在临床乳腺癌筛查与诊断中具有较好的灵敏度、特异性和准确度；癌组织与血清Cys C表达水平的异质性可能与其在乳腺癌进展中的作用密切相关。

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.