Immunohistochemistry was performed for hnRNP K, p53 and p21 in a series of 68 consecutive cases of rectal adenocarcinoma with full molecular characterization following radiochemotherapy and 14 corresponding pre‑therapeutic biopsies, and the results were correlated with clinicopathological characteristics and the percentage of vital tumor cells following therapy.
Genetic testing revealed the same TP53 mutation in tumor cells of the rectal adenocarcinoma and vulvar and endocervical lesions, demonstrating that the Paget cells originated from the same intestinal tumor.
Formalin fixed, paraffin embedded pre-therapeutical tumor biopsies (n = 22) and post-therapeutical resection specimens (n = 40) from patients with rectal adenocarcinoma (clinical UICC stage II/III) receiving standardized neoadjuvant 5-fluorouracil (5-FU) based chemoradiotherapy were studied for Ki67 and p53 expression by immunohistochemistry and correlated with TS mRNA expression by quantitative TaqMan real-time PCR after laser microdissection.
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.
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.
Expression of nuclear p53 protein in rectal carcinoma seems to be a significant predictive factor for local treatment failure after preoperative radiotherapy.
Our results suggest that the determination of p53 is a factor in predicting tumor response in patients who undergo preoperative chemoradiation therapy for rectal adenocarcinoma.
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.