Clinicopathological significance of Bcl-2 and Bax protein expression in human pancreatic cancer.
OBJECTIVE
To assess the clinicopathological significance of the expression of the apoptosis-inhibitory Bcl-2 protein (pBcl-2) and the apoptosis-promoting Bax protein (pBax) in human invasive ductal carcinomas (IDCs) of the pancreas.


METHODS
Fifty-nine surgical specimens of IDCs of the pancreas were stained immunohistochemically to detect pBcl-2 and pBax expressions whose correlation to tumor classification, staging, and prognosis was analyzed by univariate and multivariate analyses.


RESULTS
The expression of pBcl-2 and pBax was detected in 21 of 59 (35.6%) and in 29 of 59 (49.2%) patients with IDCs of the pancreas, respectively. Neither pBcl-2 nor pBax alone was correlated to TNM staging and differentiation degree of IDCs of the pancreas according to univariate analysis. By Mantel-Cox test, the median survival time after surgery for pBcl-2(+) and pBcl-2(-) groups were 14.3 and 7.3 mo, respectively (chi(2) = 9.357, P = 0.002) and that for pBax(+) and pBax(-) groups were 12.9 and 10.2 mo, respectively (chi(2) = 0.285, P>0.05). Contingency coefficient between pBcl-2 and pBax expression was 0.298, indicating that there was correlation between them (chi(2) = 5.74, P<0.05). The median survival time after surgery for pBcl-2(+)pBax(+) and pBcl-2(+)pBax(-) groups were 14.3 and 14.1 mo, respectively, and that for pBcl-2(-)pBax(+) and pBcl-2(-)pBax(-) groups were 5.9 and 9.9 mo, respectively. There was a significant difference between pBcl-2(+)pBax(+) and pBcl-2(-)pBax(+) (chi(2) = 5.06, P<0.05), such was the case for pBcl-2(+)pBax(+) and pBcl-2(-)pBax(-) (chi(2) = 7.18, P<0.01). Cox proportional hazards model for multivariate analysis was applied, indicating that pBcl-2, TNM staging, age and pBax were high risk factors of post-surgical survival time.


CONCLUSIONS
Both pBcl-2 and pBax have high expression in IDCs of the pancreas, indicating that co-expression of pBcl-2 and pBax is a good indicator of favorable prognosis in IDCs of the pancreas.
Dong
Ming
M
Department of Surgery, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China. mingdong76@yahoo.com
Zhou
Jian-Ping
JP
Zhang
Hao
H
Guo
Ke-Jian
KJ
Tian
Yu-Lin
YL
Dong
Yu-Ting
YT
D000368:Aged; D017209:Apoptosis; D044584:Carcinoma, Ductal / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein