Significance of COX-2 expression in benign and malignant breast diseases

Abstract

Objective To investigate the expression and distribution of COX-2 in benign and malignant breast disease,and the relationship among COX-2 expression and the clinicopathologic factors,hormone receptors.Methods Immunohistochemistry Was used to investigate the expression and distribution of COX-2 in 8 accessory.breasts,31 BPBDs(15 in adnosis,16 in fibroadnoma),70 IDCs(35 of them accompany with DCIS);The relationships between the expression of COX-2 and hormone receptor(ER and PR),C-erbB-2.and the clinicopathologic factors were studied respectively.Results①The expression of COX-2 in various kinds mammary diseases:8 accessory breasts were all negative;the positive rate of COX-2 in BPBD was 96.5%(30/31),among these,the positive rate of COX-2 in adnosis was 93.3%(14/15),and in fibroadnonm was 100%(16/16).The positive rate of COX-2 in DCIS was 85.7%(30/35).The intensity of COX-2 expression in DCIS of periph-IDC was higher than that in corresponding carcinoma.The positive rate of COX-2 in IDC Was 84.3%(59/70),the expression of COX-2 Was different among non-cancer gland.②COX-2 expression in BPBD was obviously higher compared with COX-2 in IDC,the difference was significant in statistics(χ2=9.39,P＜0.025).③The expression of COX-2 in DCIS was correlative with low histological differentiation(χ2=10.98,P＜0.005),PR negative(P=0.019,Fisher exact probability),and C-erbB-2 positive(P=0.0008,Fisher exact probability).The expression of COX-2 in IDC was correlative with lymph node metastasis(χ2=4.09,P＜0.05),tissue poorly differentiated(P=0.004,Fisher exact probability),PR negative(χ2=6.91,P＜0.01)and C-erbB-2 positive(χ2=5.94,P＜0.025).Conclusion COX-2 does not express in normal mammary gland.It is high-expressed in BPBD,DCIS and IDC;These indicate the up-regulation of COX-2 expression not only participates in breast carcinogenesis,but also promotes its metastasis and progression,and suggests COX-2 may down-regulate reactivity of endocrine thempy by participating in therapy resistance of PR negative breast cancer. Key words: Breast neoplasms; Oxygenases; Genes,erbB-2; Receptors,estrogen; Receptors,progesterone