[Expression and clinical significance of PDGFRalpha and PDGFRbeta in colorectal cancer].

ABSTRACT

BACKGROUND & OBJECTIVE: Platelet-derived growth factor receptor-alpha (PDGFRalpha) and -beta (PDGFRbeta) play important roles in the invasion and metastasis of solid tumors. However, their correlations to colorectal cancer have seldom been reported. This study was to detect the expression of PDGFRalpha and PDGFRbeta in colorectal cancer, and investigate their clinical significance. METHODS: The expression of PDGFRalpha and PDGFRbeta in 122 specimens of colorectal cancer and 17 specimens of normal colorectal tissues was detected by SABC immunohistochemistry. The correlations of their expression to the clinicopathologic characteristics and prognosis of the colorectal cancer patients were analyzed. RESULTS: The high expression rates of PDGFRalpha and PDGFRbeta were 68.8% and 65.6% in colorectal cancer, but no high expression was found in normal colorectal tissues. PDGFRalpha expression was positively correlated to PDGFRbeta expression in colorectal cancer (r=0.416, P<0.001). The expression of PDGFRalpha was positively correlated to the stage of primary lesion, regional lymph node metastasis, distant metastasis and Dukes'stage. The high expression rate of PDGFRbeta was significantly higher in Dukes'C and D tumors than in Dukes'A and B tumors (73.8% vs. 56.1%, P=0.040). The 3-year overall and progression-free survival rates were significantly lower in the patients with high PDGFRalpha expression than in those with low PDGFRalpha expression (61.5% vs. 72.1%, 43.2% vs. 72.8%, P<0.05); the 3-year progression-free survival rate was significantly lower in PDGFRalpha-positive patients than in PDGFRalpha-negative patients (47.3% vs. 72.1%, P<0.05). On multivariate analysis, both PDGFRalpha and PDGFRbeta were not independent prognostic factors of colorectal cancer. CONCLUSIONS: PDGFRalpha and PDGFRbeta are overexpressed in colorectal cancer, and are related with the progression of colorectal cancer. Both PDGFRalpha and PDGFRbeta are not independent prognostic factors of colorectal cancer.