Comparison of cyclo-oxygenase 2 expression in colorectal serrated adenomas to expression in tubular adenomas and hyperplastic polyps.
OBJECTIVE
Serrated adenoma (SA) is a newly defined category of colorectal neoplasia that contains features of both adenoma and hyperplastic polyp, and has two patterns, hyperplastic and cerebriform patterns. Since cyclooxygenase 2 (COX-2) has been found upregulated in colorectal cancers and adenomas, we examined whether either the hyperplastic or cerebriform pattern of SA has the potential for tumor progression and should be a target for clinical treatment.


METHODS
An immunohistochemical scoring system was used to compare COX-2 expression in colorectal SAs (n=79), tubular adenomas (n=66), and hyperplastic polyps (n=21).


RESULTS
COX-2 scores were significantly higher in SA of the cerebriform pattern (n=44) than in SA of the hyperplastic pattern (n=35). There was no difference in COX-2 scores between SA of the cerebriform pattern and tubular adenoma. In SA accompanied by hyperplastic polyp (n=26) the hyperplastic components expressed little COX-2, the same as traditional hyperplastic polyps. COX-2 expression in the SA component was similar to that in pure SA.


CONCLUSIONS
SA of the cerebriform pattern should be treated similarly as traditional tubular adenomas. COX-2 induction may additionally be involved in progression from hyperplastic polyp to SA.
Takeuchi
Manabu
M
Third Department of Internal Medicine, Niigata University School of Medicine, Japan. manabu@med.niigata-u.ac.jp
Kobayashi
Masaaki
M
Ajioka
Yoichi
Y
Honma
Terasu
T
Suzuki
Yutaka
Y
Azumaya
Masaki
M
Narisawa
Rintarou
R
Hayashi
Syun-ichi
S
Asakura
Hitoshi
H
D000236:Adenoma / Q000473:pathology*; D018256:Adenomatous Polyps / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis; D001707:Biopsy, Needle; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000473:pathology*; D046508:Culture Techniques; D051546:Cyclooxygenase 2; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis*; D008297:Male; D008565:Membrane Proteins; D011336:Probability; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D014408:Biomarkers, Tumor; D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases