Prognostic significance of immunohistochemical expression of p53 and retinoblastoma gene protein (pRB) in curatively resected gastric cancer.
BACKGROUND
The aim of this study was to determine the prognostic significance of the expression of p53 and retinoblastoma (Rb) gene products in cases of curatively resected gastric adenocarcinoma, by immunohistochemical analysis.


METHODS
Between January 1996 and December 2001, 736 curatively resected gastric cancer patients underwent immunohistochemical staining for p53 or Rb proteins (pRb), and we retrospectively analyzed the correlation of our results with the clinical outcomes of these cases.


RESULTS
High levels of expression of p53 (>25% p53-positive cells) and Rb (>50% Rb-positive cells) proteins were detected in 40.1% and 43.7% of cases, respectively. Tubular type was found to frequently exhibit higher levels of p53 expression (high expression in 44.2%) than signet ring cell type (high expression in 26.0%) (p = 0.042). The incidence of vascular invasion was lower in the high pRb expressors (43.2%) than in the pRb low expressors (56.8%), but this was not a statistically significant discrepancy (p = 0.063). Preoperative CEA levels were found to be low in high pRb expressors: initial CEA level in the high pRb expressors was 2.31 +/- 3.30 ng/mL, and was 5.18 +/- 24.80 ng/mL in the low pRb expressors (p = 0.033). Tumor depth and node metastasis were both independent of the levels of expression of p53 and Rb proteins. The seven-year overall survival rate and relapse-free survival rates of patients were 87.2% and 75.7%, respectively. Multivariate Cox regression analysis indicated that tumor stage, tumor size, patient age and pRb expression were the significant prognostic factors with regard to overall survival, and tumor stage and age were both significant factors with regard to relapse-free survival.


CONCLUSIONS
Immunohistochemical staining of retinoblastoma gene products was an independent prognostic factor for the prediction of overall survival in curatively resected gastric cancer patients.
Song
Hong Suk
HS
Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea. shs7436@dsmc.or.kr
Kim
In Ho
IH
Sohn
Soo Sang
SS
Kwon
Kun Young
KY
Lee
Won Sik
WS
D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016160:Retinoblastoma Protein / Q000378:metabolism*; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53