Clinicopathological Significance Of COX-2 Expression In Breast Cancer And Its Impact To Prognosis

Breast cancer is one of the most common malignant tumour forthe female. Recent statistics shows that incidence rates of breastcancer are increasing in all countries. The incidence is low in China,but its annual increases in incidence are 3% to 4%. COX-2 is a keyenzyme that converts arachidonic acid to PGs. Expression of COX-2is elevated in variety of human malignancies and in premalignantlesions. The aim of this study is to analysis the relationship betweenCOX-2 expression and clinicopathological parameters in breastcancer and its impact to prognostic survive. A total of 52 patients, female, aged 25-74 (average 46.8), withprimary breast cancer who were diagnosed in the years 2000 to 2001May in the First Hospital of Jilin University qualified for the studies.Tissue specimens were formalin fixed, paraffin embedded, andhistologically proved at different tumour stages: stage â… (n=7),stageâ…¡(n=38), stage â…¢(n=6), stage â…£(n=1). Histological type is:invasive ductal cancer (n=37), invasive special cancer (n=15). ERpositive are 34 cases, ER negative 18 cases, PR positive 41 cases, PRnegative 11 cases, HER-2/neu positive 19 cases, HER-2/neu negative33 cases. Normal tissues of 9 cases were obtained about 3cm awayfrom neoplasms, which were also confirmed as non-tumor byhistology. COX-2 expressed in 61.5% (32/52) breast cancer tissues at amoderate to high level, which was significantly different from thenegligible expression in normal breast epithelia (P<0.010). ElevatedCOX-2 expression was not associated with age, tumour size,histological type, pTNM stage, ER, PR and HER-2/neu (P>0.050).There was a significant relationship between elevated COX-2expression and lymph node metastasis (P<0.050). The 1-year,3-year,5-year overall survival rate for cox-2 positive patients is93.75% (30/32),75.00% (24/32), 68.75% (22/32), and for negativepatients is 95.00% (19/20), 95.00% (19/20), 90.00% (18/20)(P<0.05).Using COX regression model, prognosis was associated with tumourstage (RR:11.32), COX-2 expression (RR:6.85)and PR expression(RR:4.59) ( P<0.05).This study illustrated that COX-2 participates carcinogensis,tumor progression and metastasis of breast cancer. COX-2 maybe anindependent prognostic factor for breast cancer.