Characteristics of familial juvenile polyps expressing cyclooxygenase-2.

OBJECTIVES: Familial juvenile polyposis (FJP) is a dominant genetic disorder characterized by colorectal, gastric, and small bowel juvenile polyps, and high risk for gastrointestinal cancer. Patients are treated by repeated endoscopic polypectomies and elective surgery. We determined the characteristics of FJP polyps expressing cyclooxygenase-2 (COX-2). METHODS: A total of 115 colorectal and 6 gastric polyps were available from 17 FJP patients. Comparison tissues were 18 sporadic juvenile colorectal polyps, 6 gastric hyperplastic polyps, 9 normal colons, and 3 colorectal cancers (CRCs). Histology sections were classified and stained for COX-2. The polyps' epithelium and stroma and comparison tissues were quantified for COX-2 by: area of staining (0-3) x intensity (0-3). Epithelial and stromal scores (0-9) and total scores (0-18) were evaluated in relationship to patient's age, polyp site, size, dysplasia, and stromal cellularity. RESULTS: Colonic FJP polyps mean total COX-2 score was 10.3 +/- 6.0, and that of sporadic juvenile polyps 3.6 +/- 2.2 (p < 0.01), and in contrast to the latter, FJP COX-2 scores increased significantly (p < 0.01) with polyp size. Linear regression analysis showed significant associations of COX-2 in FJP polyps with dysplasia (p < 0.01), stromal cellularity (p < 0.01), size (> or =1.5 cm) (p= 0.02), and site (right colon) (p= 0.01), and not with age. COX-2 total scores of gastric FJP polyps and hyperplastic polyps were similar. CONCLUSIONS: Expression of COX-2 in FJP polyps and its association with size and dysplasia suggest that, in these patients, chemoprevention with selective COX-2 inhibitors might be a useful adjunct therapy to colonoscopic polypectomy.

Cyclooxygenase-2 expression in the hereditary mixed polyposis syndrome.

Hereditary mixed polyposis syndrome (HMPS), characterized by hyperplastic, juvenile, admixed, serrated adenomas and eventually colorectal cancer, is managed by repeated polypectomy and surgery. We determined if HMPS polyps express cyclooxygenase-2 (COX-2). Nineteen recent HMPS polyps, from five family members, were stained for COX-2. Polyps' epithelium and stroma and comparison tissues (normal colonic mucosa [9], sporadic juvenile polyps [18], colorectal cancers [3]) were quantified for COX-2 by: area of staining (0-3) x intensity (0-3). Epithelial, stromal, and total scores were evaluated in relationship to histology and dysplasia. HMPS polyps COX-2 mean epithelial (5.0+/-3.0), stromal (6.9+/-1.9), and total (11.8+/-4.6) scores were significantly higher (P < 0.01) than sporadic juvenile polyps (0.6+/-0.7, 3.1+/-2.2, and 3.6+/- 2.2 respectively), while colorectal cancer scored 9, 9, and 18. There was a positive association (P < 0.01) among histology, degree of dysplasia, and COX-2 expression. COX-2 expression in HMPS polyps and its association with dysplasia suggest that chemoprevention might be a useful adjunct therapy.