Table 2

- Studies of cyclooxygenase-2 expression in breast cancer.

References	Normal breast tissues	BC tissues	Age	Tumor size	Histologic type	Grade	Stage	Lymph nodes metastasis	Distant metastasis	Lymphovascular invasion	Surgical margins	Disease recurrence	Survival
Present study	26.9%	42.7%	-	-	-	-	+	-	+	+	-	-	+
Chen et al¹⁷	16.7%	72.7%	-	-		+		+	+				+
Wang et al¹⁸	15.4%	78.9%	-	-		+		+	+	+			+
Muhammad et al¹⁹	44%	72.7%	-	+		+	+	+		+
Jana et al²⁰	0%	85 %	+	+		+	+	+
Bhutani et al²¹	72%	66%	-	-		+	+	-
Sharma et al²²	72%	66%	-	-		-		-
Tekin et al²³		67%	+	+		+		+		-
Nassar et al²⁴		86.0%	-	-	-	-	-	+		-
Ameen et al²⁵		48%	-	-	-	-	-	-		+
Solanki et al²⁶		58%		+			+	+		+
Gao et al²⁷		68.66%	-			+	+	-
Sicking et al²⁸		24.9%	-			+	-						+
Giaginis et al²⁹		76.9%	-	-	-	↓+	-	-					↓+
Simonsson et al³⁰		91%	+	-		↓+		-					-
Misron et al³¹		75%	-	-		↓+		-		-
Serra et al³²		66.9%	-	-			-	-					-
Aggarwal et al³³		70%				-	-	-	-			-