ABSTRACT
<p><b>OBJECTIVE</b>To examine the association of 5-lipoxygenase (5-LOX) expression with clinicopathological factors in colorectal cancer.</p><p><b>METHODS</b>Immunohistochemical stain was used to detect the 5-LOX expression in 52 resected specimens of colorectal cancer. The association between 5-LOX expression and clinicopathological factors was examined.</p><p><b>RESULTS</b>The positive rate of 5-LOX expression in 52 specimens of colorectal carcinoma was 73.1% (38/52). In 41 colorectal cancer specimens with lymph node metastasis, the positive rate of 5-LOX expression was higher than that in the specimens without metastasis (87.8% vs. 18.2%, P<0.05). The positive rate of 5-LOX expression in the specimens with deep infiltration (T3 and T4) was higher than that in the specimens with superficial infiltration (T1 and T2) (81.1% vs. 53.3%, P<0.05). The positive rate of 5-LOX expression in TNM stage III and IIII cancer was higher than that in stage I and II (79.5% vs. 53.8%, P<0.05). The positive rate of 5-LOX expression in cancers of poor differentiation and non-differentiation adenocarcinoma was higher than that of well and moderately differentiated cancer (100% vs. 50.0%, P<0.05). There were no significant differences of 5-LOX expression with tumor size,vascular invasion and peritoneal dissemination.</p><p><b>CONCLUSION</b>5-LOX expression in colorectal carcinoma is closely associated with lymph node metastasis, infiltration depth, differentiation degree and TNM stage.</p>