Relationship Between COX-2 Expression And Axillary Lymph Node Metastases In Breast Cancer And COX-2 Expression In Lymph Node Metastases Of Breast Cancer

Breast cancer is one of the most common malignant tumour forthe female in the world. The incidence of breast cancer remains high.Breast cancer is the second leading cause of cancer death in women,exceeded only by lung cancer. Expressions of COX-2 are elevated inmalignant tumour, which is related to carcinogensis, tumorprogression and metastases of breast cancer. The relation betweenexpression of COX-2 in breast cancer and metastases of axillarylymph node is not clear. Some foreign researchers studied expressionof COX-2 in sentinel lymph node of breast cancer, in the metastaticlymph nodes of colorectal carcinoma and in lymph node metastases ofcervical and vulvar cancer. There in no similar report in our country.The aim to this study is: (1)relationship between COX-2 expressionand axillary lymph node metastases in breast cancer and its impact toprognosis;(2) COX-2 expression in lymph node metastases of breastcancer and its impact to prognosis. This study contains two parts. Part One: relationship betweenCOX-2 expression and axillary lymph node metastases in breastcancer and its impact to prognosis. A total of 52 patients, female, aged25-74 (average 46.8), with primary breast cancer who were diagnosedin the years 2000 to 2001 May in the First Hospital of Jilin Universityqualified for the studies. Tissue specimens were formalin fixed,paraffin embedded, and histologically proved at different tumourstages: stage Ⅰ(n=7), stageⅡ(n=38), stage Ⅲ(n=6), stage Ⅳ(n=1).Normal tissues of 9 cases were obtained about 3cm away fromneoplasms, which were also confirmed as non-tumor by histology.Part Two: COX-2 expression in lymph node metastases of breastcancer and its impact to prognosis. One hundred and eleven positiveaxillary lymph nodes from 23 patients, female, aged 25-68 (average46.3), with primary breast cancer who were diagnosed in the years2000 to 2001 May in the First Hospital of Jilin University qualified forthe studies. Tissue specimens were formalin fixed, paraffin embeddedand pTNM of primary tumour: stageⅡ(n=17), stage Ⅲ(n=5), stageⅣ(n=1). Negative axillary lymph nodes of 31 cases were obtained,which were also confirmed as non-tumor by histology.Specimens were analyzed for COX-2 expression byimmunohistochemistry using specific monoclonal antibodies. 61.5%(32/52) of breast cancer expressed COX-2 at a moderate to highlevel, which was significantly different from the negligible expressionin normal breast epithelia (χ2=7.85,P<0.010). The expression ofCOX-2 in positive-lymph-node breast cancer was 85.0%(17/20),while it was 46.9%(15/32) in negative-lymph-node breast cancer.The expression of COX-2 in number of positive lymph node ≤4 was77.8%(7/9),and in number of positive lymph node >4 was 90.9%(10/11), which were significantly different compared with the groupof no lymph node metastases(χ2=13.23,P<0.005)。There was nosignificant relationship between prognosis with cox-2 expression indifferent lymph node status. 80.2%(89/111) of positive lymph nodesfrom 23 patients expressed COX-2 at a moderate to high level, whichwas significantly different from the expression in negative lymphnodes from 31 patients ( χ 2=23.46, P<0.005). There was nosignificant relationship between prognosis with cox-2 expression inpositive axillary lymph nodes.Our study showed that COX-2 gene was overexpressed in breastcancer specimens as compared with normal epithelia. COX-2expression level was correlated with lymph node status and thenumber of metastatic lymph node. COX-2 gene was overexpressed inpositive lymph nodes of breast cancer specimens as compared withnegative lymph nodes. COX-2 participates carcinogensis, tumorprogression and lymphatic invasion of breast cancer.