Expression of p53 and Ki-67 as prognostic factors for survival of men with colorectal cancer.

In patients with colorectal cancer (CRC) several independent prognostic factors are well-supported in the literature, including TNM stage, histological type and grade, and serum levels of carcinoembryonic antigen (CEA). All cancer cells express high levels of tissue proliferation markers, such as Ki-67 and p53, which are currently considered prognostic markers for patients with several types of cancers. We retrospectively studied 31 men (median age 65, range 48-75 years) with confirmed Dukes' B colorectal adenocarcinoma. The following parameters were recorded: age of the patients (years), baseline CEA serum levels (ng/ml), Ki-67 and p53 expression (%), and survival (months). The mean overall survival was 37.3 ± 13.7 months. The mean baseline CEA serum level was 79 ± 7.4 ng/ml, while the percentage positivity for Ki-67 and p53 in cancer tissues was 46.9 ± 19.2 and 48.7 ± 14.2, respectively. There was a significant correlation between Ki-67 and p53 expression (R=0.82, p<0.001) and an inverse relationship between survival and the expression of both Ki-67 (R=-0.67, p<0.001) and p53 (R=-0.64, p<0.001). No significant correlation was found between survival and age (R=0.22, p=0.22) or CEA (R=0.08, p=0.67). There was no relationship between CEA and age (R=0.34, p=0.06), Ki-67 (R=-0.021, p=0.90) or p53 (R=0.03, p=0.87). In conclusion, our preliminary results showed that both Ki-67 and p53 overexpression in CRC are associated with a worse outcome. In this selected group of patients, these prognostic markers were independent of age, and the preoperative CEA serum levels did not have any relationship with survival.