目的：探讨乳腺癌各分子亚型中碳酸酐酶IX(carbonic anhydrase IX，CAIX)的表达及临床意义。方法：采用免疫组织化学检测CAIX在4种不同乳腺癌分子亚型中的表达水平并分析其与临床病理参数的关系。结果：CAIX在管腔A型、管腔B型、HER-2过表达型和基底样型乳腺癌中的阳性表达率分别为6.65%(28/421)、12.50%(7/56)、60.61%(40/66)和32.31%(84/260)。ER阴性的HER-2过表达型及基底样型乳腺癌组织中，CAIX的阳性表达明显高于ER阳性的管腔A型和管腔B型(P<0.001)，并且HER-2过表达型乳腺癌组织CAIX的阳性表达率明显高于基底样型相比，差异有统计学意义。CAIX与乳腺癌的组织学分级、淋巴结转移、临床分期及高增殖指数相关(P<0.05)，而与患者年龄、是否绝经及肿瘤大小无关。结论：CAIX在不同乳腺癌分子亚型中的表达具有明显差异，可能与ER阴性乳腺癌关系更密切，并在乳腺癌的侵袭、转移中发挥重要作用，可能成为乳腺癌浸润、进展及预后评估的指标。
Expression and clinical significance of CAIX in molecular subtypes of breast carcinoma
Objective: To investigate the expression and clinical significance of CAIX in the molecular subtypes of breast carcinoma. Methods: The expression of CAIX was detected by immunohistochemistry in different subtype of breast carcinoma. Results: Positive expression rates of CAIX in Luminal A, Luminal B, HER-2 over-expression and basal-like subtypes were 6.65% (28/421), 12.50% (7/56), 60.61% (40/66) and 32.31% (84/260), respectively. The positive expression rate of CAIX in ER-negative breast carcinomas (HER-2 over-expression and basal-like) were significantly higher than that in ER-positive subtypes (luminal A and luminal B) (P<0.001). The expression rate of CAIX in HER-2 over-expressing subtype is much higher than that in basal-like ones. There was a significant correlation between CAIX with the histopathologic grade, lymph node metastasis, pTNM stage and higher Ki-67 index (P<0.05), while there was no significant correlation between CAIX with patients’ age, whether menopause or not and the size of tumor. Conclusion: The over-expression of CAIX was different in 4 subtypes of breast carcinoma, and it may be closely related to the ER-negative breast cancer. CAIX may play an important role in the invasion and metastasis of breast carcinoma, and may be used as an indicator for invasion, progress and prognosis evaluation.