We investigated the factors modulating adjuvant cancer therapies by examining p53 gene mutations and chromosome 17p allelic losses in 15 rectal cancers treated by a preoperative combined therapy consisting of radiation, intraluminal hyperthermia and 5-fluorouracil suppositories.
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.
Fifty patients with locally advanced rectal cancer were treated with preoperative radiotherapy combined with mitomycin C and capecitabine. p21 and p53 immumohistochemical staining was performed on pretreatment biopsies and the results were compared with tumor regression according to grading systems by Dworak (TRG grades) and by Wheeler (RCRG grades).
Utilizing a novel in silico clonal evolution algorithm, we identified common tumor-initiating events involving APC, KRAS and TP53 genes in RCC, LCC and rectal cancers.
Therefore, this combination therapy can induce an additive or synergistic anti-tumour effect in rectal cancers with wild-type p53 as well as in those with mutated p53 through apoptosis, offering new therapeutic opportunities and a better prognosis.
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.
Two other family members, one with a rectal carcinoma aged 55, the other with two separate benign lesions under the age of 45, were both wild-type for the TP53 mutation.
Little information is available on the clinical significance of cancer-related genes such as KRAS, NRAS, BRAF, PIK3CA and TP53 in nonmetastatic rectal cancer.
The associations between p53 protein expression and TP53 polymorphism, biological behavior and prognosis in low rectal cancer were systematically analyzed.
Thus, our current meta-analysis indicates no evidence for the association between the p53Arg72Pro polymorphism and CRC risk in the Asian population, but significant association in Chinese population, especially for rectal cancer and in men.
Without correction for multiple testing, one polymorphism in GPX2 and three polymorphisms in GPX3 were associated with a significant risk reduction for rectal cancer at α = 0.05, specifically for rectal cancers with TP53 mutations.
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.
There was no correlation between p53, deleted in colorectal cancer gene, or thymidylate synthase immunohistochemical staining or between p53 polymerase chain reaction-single-strand conformation polymorphism and local recurrence or survival in locally advanced low rectal cancers treated with preoperative adjuvant therapies.
The results of the present meta-analysis indicate that P53 status is a predictive factor for response in rectal cancer patient undergoing neoadjuvant radiation-based therapy.
Mutations in p53 tumor suppressor gene were examined in 44 Chinese patients with rectal cancer, including 22 cases with advanced schistosomiasis japonica and 22 cases without schistosomiasis.