The Study On The Correlation Between Neuroendocrine Differentiation And Androgen-independent In Prostate Cancer Conversion

Objective: This study was designed to investigate prostate cancerassociated protein: chromogranin A(Cg A) and synaptophysin(SYN), and to test their expression in benign prostate hyperplasia and prostate cancer, understanding that clinical significance.Methods: After approved by the Ethics Committee of North Sichuan Medical college and Affiliated Hospital of North Sichuan Medical college, and after agreed by patients and their families, 70 cases of prostate cancer organization were collected, in which there were 9 cases from prostate cancer radical surgery specimens, and those patients’ age were 61-83 years old with median age were 67 years old. All 70 cases of prostate cancer patients were accepted clinical formal follow-up. The samples were treated with endocrine castration hormones and reached castration level(testosterone<50ng/dl), including for conditions: endocrine treatment of sensitive or non-sensitive, with or without distant metastasis. In addition, 30 cases of surgical resection for benign prostate hyperplasia were collected from the Affiliated Hospital of North Sichuan medical college at the same time, as a control. All of the 100 patients have complete data, which were diagnosed by pathology. All samples were fixed by 10% formaldehyde, embeded by paraffins, and sliced. Then all the slides were staining by immunohistochemistry to test the expression of SYN and Cg A.Results: According to the Immunohistochemistry, 92.9% were positive expression of Cg A in metastatic disease of PCa, and 78.6% were positive expression of SYN in metastatic disease of PCa. While there were only 36.6 % and 17.9% positive expression of Cg A and SYN respectively in sample of non-metastatic disease. Staining for marker Cg A and SYN were seen in 38.8% and 42.9% respectively in samples from patients who accepted and were sensitive to hormone therapy. Instead, the positive expression rate of Cg A and SYN in samples from people who accepted endocrine therapy with low sensitivity or insensitivity were relatively high, 90.4% and 81% respectively. It is note worthy that samples with negative Cg A and SYN staining were picked up in benign prostatic hyperplasia; the positive results were obtained higher rate for metastatic disease and insensitivity to endocrine therapy. The positive expression rates of Cg A and SYN were higher than negative expression rates in prostate cancer with or without metastasis and which were insensitive to endocrine therapy(P<0.05), which were lower than negative expression rates in people who were sensitive to endocrine treatment.Conclusion: The expression of Cg A and SYN in prostate cancer tissue is correlated with overall, cancer specific occurrence and development of metastatic disease and the sensitivity to endocrine therapy of prostate cancer. Monitoring the expression of Cg A and SYN, it has clinical significance for the selection of castrated treatment and for the prognosis of prostate cancer.