Potential role of bcl-2 expression and apoptotic body index in colorectal cancer.
OBJECTIVE
Tumor growth is the result of proliferation and apoptosis. Bcl-2 is a proto-oncogene that inhibits apoptosis. The aim of the study was to investigate the clinicopathological correlations, interactions and prognostic significance of both bcl-2 protein expression and apoptotic body index (ABI) in colorectal cancer (CRCs).


METHODS
Sixty colorectal cancer (CRC) patients had colonoscopic biopsies and tumor markers assay (CEA-CA19.9). The resected specimens were subjected for routine pathologic assessment, immunocytochemical staining for bcl-2 protein detection and immunofluorescence method for apoptotic body index.


RESULTS
Bcl-2 immunostaining (IS) was positive in 29 patients (48.3%). The bcl-2 positive IS was significantly associated with -ve vascular invasion (P=0.05) and early tumor staging (P<0.01); the apoptotic body index had a median 3.5% and is neither correlated with bcl-2 or the clinicopathological variables. The overall survival (OS) was significantly associated with ABI (P<0.01), but not with bcl-2 expression and on bi-variant analysis, the OS is significantly better with high ABI in bcl-2 positive immunophenotype (P<0.05).


CONCLUSIONS
Bcl-2 is a marker of favorable parameters (-ve angioinvasion and early tumor staging) but of no prognostic value. The apoptotic body index (ABI) is a favorable prognostic factor and may be used as a stratification parameter especially the high ABI in bcl-2 +ve CRCs.
El-Awady
Saleh
S
Department of Surgery, Mansoura University, Egypt. elawadysaleh@yahoo.com
Morshed
Mosad
M
El-Shobaky
Mohamed
M
Abo-Hashem
Maha
M
Ghazy
Hosam
H
D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality; D000328:Adult; D017209:Apoptosis / Q000502:physiology*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011379:Prognosis; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2