We investigated p53 and its downstream effectors p21WAF1/CIP1, BAX, and hMSH2 as well as the proliferation marker Ki-67 (mki-67/MIB-1) in patients undergoing preoperative radiochemotherapy for rectal carcinoma to identify prognostic and predictive factors.
The hot mutation areas of p53 gene (in exons 5-8) and K-ras gene (in codon 5/12 and 13) were detected with polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), and overexpression of p53 protein was detected with immunohistochemistry (IHC) in the 97 specimens of rectal cancer.
TP53 was associated with colorectal cancer, but the different value levels of mRNA expression were not associated with survival rate of colon and rectal cancer.
The associations between p53 protein expression and TP53 polymorphism, biological behavior and prognosis in low rectal cancer were systematically analyzed.
Expression of p53 mRNA is a useful predictor of survival in patients with stage III or rectal cancers, with a significant association with CD44 mRNA expression.
Expression of nuclear p53 protein in rectal carcinoma seems to be a significant predictive factor for local treatment failure after preoperative radiotherapy.
It may be possible, that the mutations and protein overexpression of K-ras and p53 in female rectal carcinoma have different clinical impact on patient survival as suggested in previous studies concerning colorectal carcinoma of both sexes.
The predictive capacities of PrxI and p53 were also assessed by relating the immunohistochemical staining of a retrospective series of rectal cancer cases to the clinical outcome.
This study was designed to determine whether pretreatment cyclooxygenase-2 and p53 protein expression were predictors of histopathologic response in patients with rectal cancer treated with preoperative short-term chemoradiotherapy.