Abstract: Objective:To investigate the expression of Cterminal tensinlike (CTEN) protein and its correlations with clinicopathological characteristics and prognosis in patients with colorectal cancer.
Methods: The retrospective casecontrol study was adopted. The clinical data of 153 patients with colorectal cancer who were admitted to the Affiliated Hospital of Jiangsu University between January 2010 and December 2012 were collected. The expression of CTEN protein were detected by immunohistochemistry. Observed indices included: (1) expression of CTEN protein was detected by immunohistochemistry. (2) Relationships between the expressions of CTEN protein and clinicopathological characteristics of patients. (3) Relationships between the expressions of CTEN protein and prognosis of patients. The followup of telephone interview was performed to detect survival of patients untill May 2015. Count data were analyzed using twosided chisquare test. Survival curve was drawn using the KaplanMeier method, and survival analyses was done using the Logrank test. Univariate and multivariate analyses of prognosis were done using COX regression model.
Results: (1) Expressions of CTEN protein in cancer tissues and adjacent tissues were located at the cytoplasms. The positive expression rate of CTEN protein was 92.16%(141/153) and 20.26%(31/153) in cancer tissues and adjacent tissues, respectively, with a statistically significant difference (χ²=160.647, P<0.05). High expression of CTEN protein was 35.95% (55/153) and 6.54% (10/153) in cancer tissues and adjacent tissues, respectively, with a significant difference (χ²=39.561, P<0.05). (2) The high expression rate of CTEN protein was 16.30% and 63.57% in tumor with maximum diameter<5 cm and ≥5 cm, 31.15% and 54.84% in the Ⅰ-Ⅲ and Ⅳ stages of TNM stage, 42.39% and 26.23% in tumor with and without perineural and/or vascular invasion, respectively, showing significant differences (χ²=38.670, 6.026, 4.161, P<0.05). (3) Of 153 patients with colorectal cancer, 109 received chemotherapy, radiotherapy and/or biological targeted therapy after surgery. There were 41 of 55 patients with high expression of CTEN protein and 68 of 98 patients with low expression of CTEN protein receiving chemotherapy, radiotherapy and/or biological targeted therapy after surgery, respectively, showing no significant difference (χ²=0.457, P>0.05). All the 153 patients were followed up for 4.8-62.3 months with a median time of 27.5 months. The 3year tumorfree survival (Ⅰ-Ⅲ stages) and overall survival (Ⅰ-Ⅳ stages) rates were 52.23% and 39.71% of patients with high expression of CTEN protein, 76.89% and 74.12% in patients with low expression of CTEN protein, respectively, showing significant differences (χ²=15.727, 15.131, P<0.05). Patients with colorectal cancer of Ⅳ stages didn′t achieve R0 resection and were not involved in tumorfree survival. Results of univariate analysis showed that tumor maximum diameter, histologic grade, TNM stage, tumor with perineural and/or vascular invasion and expression of CTEN protein were associated with the prognosis of patients ［HR=4.39, 2.08, 5.73, 3.56, 2.03, 95% confidence interval (CI): 2.49-7.74, 2.21-3.55, 3.29-9.98, 1.8²-6.95, 1.18-3.48, P<0.05］. Results of multivariate analysis showed that maximum diameter≥ 5 cm, Ⅳ stage of TNM stage and high expression CTEN protein were independent risk factors affecting the poor prognosis of patients with colorectal cancer (HR=2.24, 3.57, 2.03, 95 %CI: 1.13-4.20, 1.94-6.59, 1.03-3.98, P<0.05).
Conclusions:The expression of CTEN protein is upregelated in colorectal cancer compared with adjacent normal tissues. There is increased expression of CTEN protein in colorectal cancer tissues with maximum diameter of tumor ≥5 cm, high TNM stage and perineural and/or vascular invasion. High expression of CTEN protein is also an independent predicting factor of prognosis.