Objective: To investigate the influencing factors of the local immunity in tissues of hepatocellular carcinoma (HCC) before and after percutaneous microwave coagulation therapy (PMCT).
Methods: Seventy-eight patients with HCC diagnosed by needle biopsy of liver underwent PMCT. Before the treatment and three and 17 days after the treatment specimens of carcinoma tissues were obtained by ultrasound-guided liver biopsy. The extents of infiltration of CD3(+) cell, natural killer cells (CD56(+)), and macrophages (CD68(+)), and the expression rate of proliferating cell nuclear antigen (PCNA) were evaluated by immunohistochemistry. The relation between the extents of immunocyte infiltration and the clinical parameters was analyzed with multiple regression.
Results: Before PMCT infiltration of the three kinds of immunocytes was found in the carcinoma tissues to different degrees with a great variation among individuals. A remarkable increase in the extent of infiltration of the three kinds of immunocytes was found three days after the treatment and continued or remained till the 17th post-PMCT day (P < 0.01). The post-PMCT extent of immunocyte infiltration was positively correlated with the pre-PMCT extent (CD3(+): r = 0.256, P = 0.005; CD56(+): r = 0.257, P = 0.002; CD68(+): r = 0.275, P = 0.001). A negative correlation was found between the extent of immunocyte infiltration and serum alpha-fetal protein (AFP) and between the extent of immunocyte infiltration and tumor size (for serum AFP, CD3(+): r = -0.075, P = 0.049; CD56(+): r = -0.062, P = 0.041; CD68(+): r = -0.007, P = 0.035; for tumor size, CD3(+): r = -0.074, P = 0.051; CD56(+): r = -0.100, P = 0.012; CD68(+): r = -0.109, P = 0.038). No correlation was found between the extent of immunocyte infiltration and age of patient, Child-Pugh class of tumor, grade of tumor differentiation, and number of tumor. The extent of immunocyte infiltration was lesser in the carcinoma tissues with higher expression rate of PCNA. The extent of immunocyte infiltration was greater in the carcinoma tissues where PCNA expression was negative and carcinoma cells had necrotized but with their structure recognizable. No immunocyte infiltration was found in the necrotic and structureless tumor tissues.
Conclusion: The local immunocyte infiltration in patients with HCC was influenced by serum AFP and the grade of tumor cell necrosis pre- and post-PMCT. Destruction of tumor tissue in situs by PMCT is the premise of increase of immunocyte infiltration. Before PMCT improving the immune status of the patients helps enhance the local immune response.