ABSTRACT
Colorectal cancer is one of the leading causes of cancer-related death worldwide. Molecular biomarkers could help to predict patient outcome and to identify patients who benefit from adjuvant therapy. Pontin and Reptin are ATPases which are involved in transcriptional regulation, DNA damage repair and regulation of cell proliferation. Many interaction partners of Pontin and Reptin such as ß-catenin and c-myc are important factors in carcinogenesis. We hypothesized that Pontin and Reptin expression may be a negative predictor for survival in colorectal carcinoma. Specimens from 115 patients with primary colon adenocarcinomas UICC stage III and primary rectal adenocarcinomas UICC stage II and III curatively resected at the Department of Surgery, Charité Berlin, were evaluated. Clinical follow-up data were complete and mean follow-up time of patients was 51.8 months. We evaluated the expression of Pontin, Reptin and Ki-67 by immunohistochemistry. Patients with Pontin-positive carcinomas showed no differences in recurrence-free survival (p=0.109) and overall survival (p=0.197). There were no differences in Reptin-positive carcinomas and Ki-67-positive carcinomas in recurrence-free survival (p=0.443 and p=0.160) and overall survival (p=0.477 and p=0.687). Patients with Pontin-positive colorectal carcinomas receiving adjuvant therapy had a significantly worse recurrence-free survival (p=0.008) and overall survival (p=0.011) than Pontin-negative patients with adjuvant therapy. In UICC stage III, Pontin-positive colorectal carcinomas had a significantly worse recurrence-free survival (p=0.028). Pontin-positivity seems to be a negative predictor for response to adjuvant therapy in colorectal cancer patients and may help to identify patients with adverse outcome in advanced tumor stages.
Subject(s)
Carrier Proteins/metabolism , Colorectal Neoplasms/mortality , DNA Helicases/metabolism , ATPases Associated with Diverse Cellular Activities , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Adenocarcinoma/mortality , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/metabolism , Colorectal Neoplasms/metabolism , Disease-Free Survival , Female , Humans , Ki-67 Antigen/metabolism , Male , Middle Aged , Neoplasm Recurrence, Local , Proto-Oncogene Proteins c-myc/metabolism , Treatment OutcomeABSTRACT
The prognostic value of p53 and p21 expression in colorectal cancer is still under debate. We hypothesize that the prognostic impact of p53 expression is dependent on p21 status. The expression of p53 and p21 was immunohistochemically investigated in a prospective cohort of 116 patients with UICC stage II and III sporadic colorectal cancer. The results were correlated with overall and recurrence-free survival. The mean observation period was 51.8 ± 2.5 months. Expression of p53 was observed in 72 tumors (63%). Overall survival was significantly better in patients with p53-positive carcinomas than in those without p53 expression (p = 0.048). No differences were found in recurrence-free survival (p = 0.161). The p53+/p21- combination was seen in 68% (n = 49), the p53+/p21+ combination in 32% (n = 23). Patients with p53+/p21- carcinomas had significantly better overall and recurrence-free survival than those with p53+/p21+ (p < 0.0001 resp. p = 0.003). Our data suggest that the prognostic impact of p53 expression on sporadic colorectal cancer is dependent on p21 status.
ABSTRACT
There is no clear evidence on the prognostic and predictive value of abnormal p53 expression in colorectal cancer. The major downstream protein, p21, a cell cycle inhibitor, is transcriptionally regulated by p53. The prognostic impact of p21 expression in colorectal carcinomas is still under debate. In this study, we investigated the expression of p21 and p53 in a prospective cohort of 116 sporadic colorectal carcinomas at UICCII/III stage. We observed an expression of p21 in 26% and p53 in 63% of the carcinomas by immunohistochemistry. Patients with p21-negative colorectal carcinomas had a significant better recurrence-free and overall survival than patients with p21-positive carcinomas (p=0.02 and p=0.005). Expression of p53 was related to a better overall survival (p=0.048). The combination of p21-negative/p53-positive expression was significantly related to better recurrence-free and overall survival (p=0.007 and p=0.0001) and gained independent prognostic significance (HR: 3.4, p=0.01). Moreover, patients with combined p21-/p53+ expression had a remarkable benefit in overall survival after adjuvant chemotherapy as compared to the p21-/p53- subgroup (HR: 3.6, p=0.027). Our data suggest that the assessment of both p53 and p21 expression may provide prognostic information in colorectal cancer patients. This combination might be helpful to identify patients who could benefit from chemotherapy.
