Expression Of PRL-3 Protein In Patients With Dukes'C Colorectal Cancer And Its Association With Liver Metastasis And Prognosis

Backgroud: Colorectal cancer is one of the most common gastrointestinal tumors, and its prognosis is poor.The 5-year survival rate of post operation is about 50%, resulting in treatment failure is mainly due to recurrence and metastasis, while the liver is the most common colorectal cancer metastatic sites. PRL-3 was a metastasis-related gene discovered in recent years and belonged to protein tyrosine phosphatase family. Since Saha found PRL-3 was highly expressed in colorectal cancer metastasis and reported its relationship with malignant tumors for the first time in 2001, more and more studies have identified that PRL-3 are highly expressed in a variety of malignant tumors, such as colorectal cancer, gastric cancer, breast cancer, ovarian cancer and liver cancer, etc, and showed a close relationship with tumor proliferation, invasion, especially metastasis.Objeetive: To investigate the expression of PRL-3 protein and its relationship with clinical and pathological factors in patients with Dukes'C colorectal cancer, and analyze the correlation between the expression level of PRL-3 with metachronous liver metastasis and prognosis, with a view to provide a basis for clinical treatment and follow-up.Material and Methord: All patients with Dukes'C colorectal cancer treated with radical surgery at Guangxi Medical University from Jan. 2003 to Dec. 2006 were identified, and Collected their pathology and clinical follow-up data.Selected all patients with metachronous liver metastases as the experimental group A, randomly selected 80 cases without liver metastasis in a random number table method as the experimental group B, And in all Dukes'C patients randomly selected 60 cases of adjacent normal tissues of tumour as the control group. The expression of PRL-3 protein was examined by Immunohistochemistry in primary colorectal cancer and adjacent normal tissues. The results were used to analyze the relationship between the expression of PRL-3 and clinical and pathological factors, metachronous liver metastasis and prognosisResult:1. Expression of PRL-3 in primary colorectal carcer and adjacent normal tissues: The positive rate of PRL-3 in colorectal carcer of experimental groups was 32.8%(38/116),and 15.0%(9/60)in adjacent normal tissues of control group respectively, which showed significant difference (P=0.012).2. Expression of PRL-3 in primary colorectal carcer with and without metachronous liver metastasis: The positive rate of PRL-3 in experimental group A was 47.2%(17/36),and 26.3%(21/80)in experimental group B respectively, which showed significant difference (P=0.026).3. The association of PRL-3 protein with clinicopathologic factors: Expression of PRL-3 in primary colorectal carcer showed a close correlation with metachronous liver metastasis and recurrence and metastasis, but not correlated with gender, age, course of disease, tumor location, histological type, differentiation, depth of invasion and other clinicopathologic factors.4. The association of PRL-3 protein with prognosis: The survival time of colorectal cancer patients with PRL-3 positive expression was significantly shorter than those with negative expression(P=0.003),and Disease-free survival of colorectal cancer patients with PRL-3 positive expression was also shorter than those with negative expression(P=0.036).Conclusion: The expression of PRL-3 protein in Dukes'C stage primary colorectal carcer was higher than their adjacent normal tissues, and in primary colorectal carcer with metachronous liver metastasis was higher than those without metastasis. Expression of PRL-3 in Dukes'C stage primary colorectal carcer showed a close correlation with metachronous liver metastasis and survival prognosis. These results suggest that the level of PRL-3 is a effective predictor of metachronous liver metastasis and poor prognosis for patients with Dukes'C stage colorectal cancer. It will be helpful to postoperative treatment and postoperative follow-up to detect the level of PRL-3 after radical operation of Dukes'C stage colorectal carcer, which will show great signifcance to early detection of metachronous liver metastases, better survival and prognosis.