ABSTRACT
Monitoring the long-term radiotherapy-associated molecular changes in low-grade gliomas (LGGs) facilitates the understanding of LGG response to radiotherapy. In this study, we used immunohistochemistry to analyze the expression of Ki-67, tumor protein P53 (TP53), P21, and P27 in 8 paired WHO grade II astrocytoma samples. The interval between radiotherapy (RT) and the second surgery was more than 3 months in all cases. The average Ki-67 labeling index (LI) was 5.3% in pre-RT samples and 11.54% in post-RT samples. Ki-67 LI was higher in the primary tumors that underwent malignant transformation observed at the second surgery after radiation. Post-RT Ki-67 LI decreased in 2 cases with an interval of less than 12 months between RT and the second surgery. TP53 expression was found in 3 out of 4 pre-RT samples with malignant transformation and in 1 out of 4 pre-RT samples without malignant transformation. Post-RT TP53 increased in 2 cases in which increased expression of P21 or P27 was also observed. Our study suggests that radiotherapy can inhibit WHO grade II astrocytoma proliferation as reflected by Ki-67 LI, but the effect attenuates with time. In addition, there is a tendency of malignant transformation for WHO grade II astrocytomas with a high Ki-67 level or TP53 expression in initial samples.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Astrocytoma , Metabolism , Pathology , Radiotherapy , General Surgery , Brain Neoplasms , Metabolism , Pathology , Radiotherapy , General Surgery , Cell Proliferation , Radiation Effects , Cell Transformation, Neoplastic , Radiation Effects , Cyclin-Dependent Kinase Inhibitor p21 , Metabolism , Cyclin-Dependent Kinase Inhibitor p27 , Metabolism , Immunohistochemistry , Ki-67 Antigen , Metabolism , Neoplasm Grading , Tumor Suppressor Protein p53 , MetabolismABSTRACT
<p><b>OBJECTIVE</b>Nimotuzumab is a humanized monoclonal antibody targeted against epidermal growth factor receptor (EGFR). Recent clinical studies show that patients with malignant gliomas could benefit from nimotuzumab treatment. The aim of the present study was to evaluate the efficacy and side effects of nimotuzumab in combination with chemotherapy for patients with malignant gliomas.</p><p><b>METHODS</b>The patients received 200 mg of nimotuzumab infusion intravenously over 60 minutes once weekly for the first eight weeks and then once every two weeks until unacceptable toxicity or tumor progression occurred. Individualized chemotherapy was administered based on O(6)-methylguanine-DNA methyltransferase (MGMT) expression and previous chemotherapy responses in combined with nimotuzumab.</p><p><b>RESULTS</b>Fourteen patients received a total of 122 times of nimotuzumab ranging from 2 to 20 (median 7.5 times). Combined chemotherapy regimens included: continuous 21-day temozolomide (10 cases), standard 5-day temozolomide (2 cases), teniposide plus cisplatin (1 case), and teniposide plus nimustine (1 case). Partial response (PR) and stable disease (SD) were found in 3 patients (21.4%)and 6 patients (42.9%), respectively. Disease control rate (PR + SD) was 64.3%. The median progression-free survival (PFS) was 4 months (95%CI: 0.7 - 7.3) and PFS at 6 months was 30.6%. The most common toxicities include grade I-II neutropenia (2 cases), thrombocytopenia (2 cases), lymphopenia (1 case), nausea and vomitting (3 case) and asymptomatic transaminase increase (1 case). One patient developed grade IV neutropenia and thrombocytopenia. One patient developed nimotuzumab-related acneiform rash.</p><p><b>CONCLUSIONS</b>Nimotuzumab in combination with chemotherapy has moderate activity in patients with malignant gliomas and the toxicities are well tolerable, therefore, worth further investigation.</p>