[Cyclo-oxygenase-2 and p53 immunoreactivity in superficial early colorectal carcinoma].
OBJECTIVE
De novo colorectal carcinoma shows more aggressive behavior including submucosal invasiveness. Both p53 and cyclo-oxygenase-2 (COX-2) have been shown to be involved in colon carcinogenesis, progression from adenoma to carcinoma, and submucosal invasion by tumor. We performed this study to evaluate the expression of p53 and COX-2 protein in de novo carcinoma, compared with ex-adenoma carcinoma.


METHODS
Twenty three flat adenomas, 19 ex-adenoma carcinomas, 6 de novo carcinomas were included in this study. The expression of p53, COX-2 and Ki-67 were examined immunohistochemically.


RESULTS
Both ex- adenoma carcinomas and de novo carcinomas showed similar size and shape. Positive staining for p53 was detected in 3 of 23 (13%) flat adenomas, in 11 of 19 (57.8%) ex-adenoma carcinomas (p < 0.05), and in 1 of 6 (16.6%) de novo carcinomas. Increased numbers of COX-2 positive tumor cells were observed in 1 of 23 (4.3%) flat adenomas, in 2 of 19 (10.5%) ex-adenoma carcinomas, and in 3 of 6 (50%) de novo carcinomas. COX-2 positive expression showed increased tendency in de novo carcinoma (p = 0.073). There was no correlation between COX-2, p53, and Ki-67 expression.


CONCLUSIONS
De novo carcinoma shows increased tendency of COX-2 expression, but decreased p53 expression when compared to ex-adenoma carcinoma. These immunohistochemical findings are in accordance with the fact that de novo carcinoma has no preceding adenoma, with more frequent submucosal invasion despite the small lesion size.
Kim
You Sun
YS
Department of Internal Medicine, Seoul Paik Hospital, Inje University College of Medicine, Jung-gu, Seoul, Korea. yousunk69@korea.com
Lim
So Dug
SD
Lee
Jin Kwang
JK
Kim
Seong Eun
SE
Ryu
Soo Hyung
SH
Lee
Jung Whan
JW
Moon
Jeong Seop
JS
D000236:Adenoma / Q000737:chemistry / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis; D002277:Carcinoma / Q000737:chemistry / Q000473:pathology; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000473:pathology*; D051546:Cyclooxygenase 2 / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53; D051546:Cyclooxygenase 2