p53 and bcl-2 protein expression in rectosigmoid adenomas.
OBJECTIVE
The aim of this study was to evaluate whether p53 or bcl-2 protein expression in rectosigmoid adenomas is associated with histological characteristics of the adenomas and with presence of synchronous advanced proximal neoplasms.


METHODS
Seventy-six average-risk patients who underwent total colonoscopy and had rectosigmoid adenoma(s) were studied. An adenoma was considered advanced if villous histology and/or severe dysplasia and/or diameter > 1 cm were present. p53 and bcl-2 protein expression was immunohistochemically examined using specific monoclonal antibodies.


RESULTS
p53 protein was detected in 43% and bcl-2 in 93% of the 76 rectosigmoid adenomas. Advanced compared with nonadvanced adenomas were significantly more frequently p53-positive (28 of 44 or 63.6% vs five of 32 or 15.6%, p < 10(-4)) or had a bcl-2 score of 12 (20 of 44 or 45.5% vs five of 32 or 15.6%, p = 0.007). Proximal advanced neoplasms were mainly found in patients with rectosigmoid adenomas positive for p53 and with a bcl-2 score of 12 (six of 17 or 35.3% vs 2/59 or 3.4%, OR: 15.6, p = 0.001) and in particular in those with advanced rectosigmoid adenomas positive for p53 and with a bcl-2 score of 12 (six of 13 or 46.2% vs two of 31 or 6.5%, OR: 12.4, p = 0.007).


CONCLUSIONS
p53 expression and bcl-2 protein overexpression in rectosigmoid adenomas are associated with advanced histology and a high risk of synchronous advanced proximal colon neoplasm.
Gastroenterology Department, Tzaneion General Hospital of Piraeus, Greece.
G V
GV
Papatheodoridis
N
N
Kapranos
M
M
Tzouvala
K
K
Triantafyllou
I
I
Elemenoglou
D G
DG
Karamanolis
D000236:Adenoma / Q000235:genetics / Q000473:pathology*; D018253:Adenoma, Villous / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D003110:Colonic Neoplasms / Q000473:pathology; D003113:Colonoscopy; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis / Q000235:genetics*; D012004:Rectal Neoplasms / Q000235:genetics / Q000473:pathology*; D012307:Risk Factors; D012811:Sigmoid Neoplasms / Q000235:genetics / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000235:genetics*
D000911:Antibodies, Monoclonal; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53