miR-3942-3p Increases the radiosensitivity of nasopharyngeal carcinoma through negatively regulating BARD1.

Nasopharyngeal carcinoma (NPC) has high incidence in China and East and Southeast Asia. The study was performed to investigate the effect of microRNA3942-3p (miR-3942-3p) on the radiosensitivity of NPC. Compared with non-cancer tissue, NPC had significantly lower miR-3942-3p expression. X-irradiation (IR) reduced the expression of miR-3942-3p in a dose-dependent way in NPC cells. Down-regulation of miR-3942-3p using miR-3942-3p inhibitor resulted in significantly increased cell viability, decreased apoptosis of CNE1 cells. Bax decreased and Bcl2 increased after IR. The expression of BARD1, a cancer predisposing gene, was elevated in NPC tissue. It was confirmed to be a target of miR-3942-3p using luciferase reporter assay. Down-regulation of BARD1 using siRNA significantly reduced cell viability and significantly increased apoptosis both before and after IR. The same response was observed when miR-3942-3p mimics was used to transfect BARD1-overexpressing CNE1 cells, suggesting the up-regulation of miR-3942-3p could sensitize CNE1 cells to X-rays via BARD1. Our data demonstrate that up-regulation of miR-3942-3p could sensitize NPC to X-rays via a downstream target BARD1, offering potential new strategies for radiotherapy of NPC.

A prospective study on neoadjuvant chemoradiotherapy plus anti-EGFR monoclonal antibody followed by surgery for locally advanced cervical cancer.

BACKGROUND: To investigate the efficacy and safety of neoadjuvant chemoradiotherapy plus anti-epidermal growth factor receptor monoclonal antibody followed by surgery for locally advanced cervical cancer (LACC). PATIENTS AND METHODS: Patients with histologically proven LACC were enrolled into this prospective study. All patients received intensity-modulated radiation therapy with conventional fractionation. Weekly cisplatin or nedaplatin was administered concurrently with intensity-modulated radiation therapy. Nimotuzumab, a humanized anti-epidermal growth factor receptor monoclonal antibody, was given at a dose of 200 mg per week for 6 cycles. Approximately 1 month after the completion of neoadjuvant treatment, the patients were assessed for clinical tumor response and operability based on MRI and gynecological examination. For those who were considered to be candidates for surgery, radical hysterectomy, and pelvic lymph node dissection were performed 5-6 weeks after the completion of neoadjuvant therapy. RESULTS: Twenty-eight patients were enrolled. Clinical complete response and partial response were found in 8 (28.5%) and 20 (71.5%) patients, respectively. Four patients were not eligible for surgery and 2 patients refused surgery although they were assessed as surgical candidates. They were not included in this analysis. Radical hysterectomy and pelvic lymph node dissection were performed for the remaining 22 patients. Among them, 8 (36.4%) had complete pathology response, 9 (40.9%) presented with persistent atypical cells or cervical intraepithelial neoplasia, and 5 (22.7%) presented with macroscopic and/or microscopic residual disease, according to the pathological evaluation. Median follow-up time was 22 months (range, 5-39 months). The 2-year locoregional control rate, progression-free survival rate, distant metastasis-free survival rate, and overall survival rate were 95.0%, 85.2%, 84.0%, and 90.0%, respectively. Acute toxicities were mild in general and easily manageable. Chronic toxicities were mainly limited to grade 1. No severe late toxicities were observed. CONCLUSION: Concurrent chemoradiotherapy plus nimotuzumab followed by surgery is highly effective and safe in LACC. Further studies are warranted to confirm the findings.

Three-Phase Adaptive Radiation Therapy for Patients With Nasopharyngeal Carcinoma Undergoing Intensity-Modulated Radiation Therapy: Dosimetric Analysis.

Patients with nasopharyngeal carcinoma undergoing intensity-modulated radiation therapy may experience significant anatomic changes throughout the entire treatment course, and adaptive radiation therapy may be necessary to maintain optimal dose delivered both to the targets and to the critical structures. The timing of adaptive radiation therapy, however, is largely unknown. This study was to evaluate the dosimetric benefits of a 3-phase adaptive radiation therapy technique for nasopharyngeal carcinoma. Twenty patients with nasopharyngeal carcinoma treated with intensity-modulated radiation therapy were recruited prospectively. After fractions 5 and 15, each patient had repeat computed tomography scans, and adaptive replans with recontouring the targets and organs at risk on the new computed tomography images were generated and used for subsequent treatment (replan 1 and replan 2). Two hybrid intensity-modulated radiation therapy plans (plan 1 and plan 2) were generated by superimposing the initial plan (plan 0) to each repeated new computed tomography image, reflecting the actual dose delivered to the targets and organs at risk if no changes were made to the original plan. Dosimetric comparisons were made between the adaptive replans (adaptive radiation therapy plans: plan 0 + replan 1 + replan 2) and their corresponding nonadaptive radiation therapy plans (plan 0 + plan 1 + plan 2). Comparing with the nonadaptive radiation therapy plans, the adaptive radiation therapy plans resulted in a significant improvement in conformity index for planning target volumes for primary disease, involved lymph node, high-risk clinical target volume, and low-risk clinical target volume (PTVnx, PTVnd, PTV1, and PTV2, respectively). Median V95 for PTVnx; D95, D99, V100, V95, and V93 for PTVnd; D99 and V100 for PTV1; and D95, D99, V100, V95, and V93 for PTV2 were increased significantly. There were significant dose-volume reductions, including maximum doses to the brainstem and temporal lobes, mean doses to the glottis, V50 for the supraglottis, Dmean and V30 for the left parotid, median dose to the right optic nerve, and V55 for the skin. The 3-phase adaptive intensity-modulated radiation therapy for patients with nasopharyngeal carcinoma results in improvements in target coverage and conformity index and decreased doses to some organs at risk.

Determining appropriate timing of adaptive radiation therapy for nasopharyngeal carcinoma during intensity-modulated radiation therapy.

BACKGROUND: To determine appropriate timing of an adaptive radiation therapy (ART) replan by evaluating anatomic and dosimetric changes of target volumes and organs at risk (OARs) during intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC). METHODS: Nineteen NPC patients were recruited. Each patient had repeat computed tomography (CT) scans after each five fractions and at treatment completion. Automatic re-contouring the targets and OARs by using deformable registration algorithm was conducted through CT-CT fusion. Anatomic changes were assessed by comparing the initial CT and repeated CT. Hybrid plans with re-contouring were generated and the dose-volume histograms (DVH) of the hybrid plan and the original plan were compared. RESULTS: Progressive volume reductions in gross target volume for primary disease (GTVnx), gross target volume for involved lymph nodes (GTVnd), and parotids were observed over time. Comparing with the original plan, each hybrid plan had no significant difference in homogeneity index (HI) for all the targets. Some parameters for planning target volumes for primary disease and high-risk clinical target volume (PTVnx and PTV1, respectively) improved significantly, notably starting from the 10th fraction. These parameters included mean dose (Dmean), dose to 95% of the volume (D95), percentage of the volume receiving 95% of the prescription dose (V95), and conformity index (CI) for PTVnx, and Dmean, D95, and CI for PTV1. The dosimetric parameters for PTVnd remained the same in general except for D95 and V95 which had significant improvement at specific time points; whereas for PTV2, similar trend of dosimetric changes was also observed. Dose to some OARs increased significantly at some time points. CONCLUSIONS: There were significant anatomic and dosimetric changes in the targets and OARs. The target dose coverage in the hybrid plans did not get worse, but overdose occurred in some critical structures. Significant dosimetric changes should be considered as a trigger point at which ART replanning is indicated. D95/V95/CI for PTV2, Dmax for the brain stem, spinal cord, right eyeball and left lens, and Dmean/V30 for the parotids and glottis were taken into account for predicting the need for ART. Two replans at the 5th and 15th fractions were suggested.

Dosimetric study of a respiratory gating technique based on four-dimensional computed tomography in non-small-cell lung cancer.

This study sought to compare the differences in target volumes and dose distributions to the targets and organs at risk (OARs) between a four-dimensional computed tomography (4DCT)-based respiratory-gated intensity-modulated radiation therapy (IMRT) plan (PlanEOE) and a three-dimensional CT (3DCT)-based IMRT plan (Plan3D) in patients with non-small-cell lung cancer (NSCLC). For 17 patients with Stages I-III NSCLC, both 4DCT data and conventional 3DCT data were obtained. The Plan3D and PlanEOE were designed based on 3DCT data and 4DCT data, respectively. The displacements of the gross tumor volume (GTV) centroid were 0.13 ± 0.09 cm, 0.15 ± 0.1 cm, and 0.27 ± 0.27 cm in the right-left, anterior-posterior, and superior-inferior directions, respectively. The volume of the GTVEOE was 3.05 ± 5.17 cm(3) larger than that of the GTV3D. The volume of the PTV3D was 72.82 ± 48.65 cm(3) larger than that of the PTVEOE. There was no significant difference between the PTV3D and PTVEOE for V55.8, V60, V66 and the homogeneity index. The PTV3D had a lower target conformity index than the PTVEOE (P = 0.036). PlanEOE had a significantly lower lung V10, V20, V30, V40 and mean lung dose (MLD) than Plan3D. For the heart, PlanEOE had a significantly lower V30 and mean dose. In conclusion, 4DCT is an appropriate method for assessing the displacement of the GTV centroid in three dimensions. PlanEOE has smaller PTVs and a decreased dose and volume for the normal lung and heart, as compared with Plan3D.

Interfractional and intrafractional errors assessed by daily cone-beam computed tomography in nasopharyngeal carcinoma treated with intensity-modulated radiation therapy: a prospective study.

This prospective study was to assess interfractional and intrafractional errors and to estimate appropriate margins for planning target volume (PTV) by using daily cone-beam computed tomography (CBCT) guidance in nasopharyngeal carcinoma (NPC). Daily pretreatment and post-treatment CBCT scans were acquired separately after initial patient setup and after the completion of each treatment fraction in 10 patients treated with IMRT. Online corrections were made before treatment if any translational setup error was found. Interfractional and intrafractional errors were recorded in the right-left (RL), superior-inferior (SI) and anterior-posterior (AP) directions. For the translational shifts, interfractional errors >2 mm occurred in 21.7% of measurements in the RL direction, 12.7% in the SI direction and 34.1% in the AP direction, respectively. Online correction resulted in 100% of residual errors ≤2 mm in the RL and SI directions, and 95.5% of residual errors ≤2 mm in the AP direction. No residual errors >3 mm occurred in the three directions. For the rotational shifts, a significant reduction was found in the magnitudes of residual errors compared with those of interfractional errors. A margin of 4.9 mm, 4.0 mm and 6.3 mm was required in the RL, SI and AP directions, respectively, when daily CBCT scans were not performed. With daily CBCT, the margins were reduced to 1.2 mm in all directions. In conclusion, daily CBCT guidance is an effective modality to improve the accuracy of IMRT for NPC. The online correction could result in a 70-81% reduction in margin size.

Identification of prognostic biomarkers for response to radiotherapy by DNA microarray in nasopharyngeal carcinoma patients.

Nasopharyngeal carcinoma (NPC) is a malignancy with an unusually variable incidence rate across the world. Radiotherapy is the primary treatment modality for NPC, but radiation resistance remains a serious obstacle to successful treatment in many cases. To identify the genes involved in this resistance and to find molecular markers for predicting NPC response to radiotherapy, we compare the expression profiles of 12 radiation-resistant patient biopsy specimens and 8 radiation-sensitive patient biopsy specimens using DNA microarray, containing 14112 human unigenes. A total of 111 aberrantly expressed genes were identified, of which ZNF608 and CSF1R were up-regulated in the radiation-resistant NPC compared with radiation-sensitive NPC, and the results were confirmed by real-time RT-PCR in 17 independent NPC patient specimens. Biostatistics and bioinformatics analyses were performed to detect the potential pathway underling this resistance, 26 pathways (9 categories) were found probably associated with radiation-resistant NPC, such as cell ion homeostasis, cell proliferation, receptor protein signalling, membrane system, humoral immune response, as well as cytokines and inflammation. We suggest the radiation-resistant capacity of NPC was mostly due to the change of cell Ca²âº homeostasis promoting anti-apoptosis, DNA repair and rescuing tumour cells under radiation therapy. Cell proliferation promotion induced by extracellular and intracellular factors may maintain tumour size under radiotherapy leading to recurrence after treatment. Our study reveals that at least 2 ectopically expressed genes play important roles in prognosis of NPC radiotherapy and may serve as potential targets for novel radiation therapeutic strategies in the future.

Feasibility and efficacy study of weekly cisplatin with concurrent intensity-modulated radiation therapy for nasopharyngeal carcinoma: preliminary results.

The aim of this study was to assess the feasibility and efficacy of a weekly cisplatin 40 mg/m(2) regimen in patients with nasopharyngeal carcinoma treated concurrently with definitive intensity-modulated radiation therapy (IMRT). The primary endpoints were treatment compliance and acute toxicities. Twenty-two patients with newly diagnosed NPC were recruited in this phase II trial. All patients received definitive IMRT concurrently with weekly cisplatin 40 mg/m(2) for six cycles. The treatment technique was split-field IMRT (SF-IMRT) before August 2009 and whole-field IMRT (WF-IMRT) thereafter. The median follow-up time was 15.1 months (range, 1.5-30 months). No patients experienced regional recurrence or distant metastasis. One patient developed local recurrence. One patient died of non-malignant disease. For all patients, the 1-year overall survival, local recurrence-free survival, regional recurrence-free survival, and distant metastasis-free survival were 95.5%, 95.5%, 100%, and 100%, respectively. All patients received the full dose of RT. Twenty-one patients (95.5%) completed all six cycles of chemotherapy (CHT). Three patients experienced treatment delay. Of them, one had CHT delay, and the other two had IMRT delay. No treatment-related death was found. Acute toxicities were generally mild or moderate. Grade 3 and 4 toxicities accounted for less than 10% of overall occurrence in each corresponding category except for a relatively higher rate in stomatitis (Grade 3, 27%). Renal function impairment was not found. Weekly cisplatin with concurrent IMRT appears to be feasible and effective in treating NPC patients and these findings warrant further investigation.

Intrathoracic Endotracheal Metastasis from Nasopharyngeal Carcinoma: A First Case Report and Review of the Literature.

Intrathoracic endotracheal metastasis from a very distant site is extremely rare. We report the first case of such a disease in a 68-year-old man with nasopharyngeal carcinoma who presented with a cough and hemoptysis 34 months after finishing radiotherapy. Prior to tracheal metastasis, he developed a solitary metastasis in the lung and underwent chemotherapy followed by radiotherapy. Computed tomography showed the presence of an enlarged lymph node in the para-aortic arch. Fiberoptic bronchoscopy revealed an endotracheal tumor 1 cm above the carina. Histological and immunohistochemical analyses confirmed its nasopharyngeal origin. He was treated with conventional radiotherapy and three-dimensional conformal radiotherapy; complete tumor remission was achieved. He died of nonmalignant disease with no signs of tumor recurrence 2 years after treatment completion. Radiotherapy may be an appropriate management approach to achieve long-term tumor control for this disease.

Concurrent chemoradiotherapy in locally advanced nasopharyngeal carcinoma: a treatment paradigm also applicable to patients in Southeast Asia.

The majority of nasopharyngeal carcinoma (NPC) patients present at locally advanced stage. The poor prognosis has led to increasing interests in exploring the use of chemotherapy (CT). Intergroup-0099 trial was the first randomized trial comparing concurrent chemoradiotherapy (CCRT) with radiotherapy (RT) alone. Its outcome established the treatment standard in the United States as standard of care for locally advanced NPC. However, criticism has been arisen, particularly about its reproducibility and applicability in Southeast Asia where NPC is an endemic disease. Subsequently, new evidence has been provided by a large number of publications from various centers. In this article, through comprehensively analyzing recent meta-analyses and randomized controlled trials performed in Asian centers, we conclude that CCRT as a treatment paradigm is also applicable to patients in Southeast Asia and should be standard of practice in locally advanced disease. However, the CT regimen varied markedly among those trials, and the optimal regimen and scheduling remains to be determined. Moreover, a number of patients experienced toxicities and the treatment compliance was generally poor. With the emergence of new RT techniques such as intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT), the role of concurrent CT with these new techniques needs to be tested. New chemotherapeutics have been investigated in the recurrent or metastatic disease. However, their effectiveness in previously untreated NPC is unclear. Previous efforts have been made for immunotherapy and targeted therapy in palliative setting. Their role in newly diagnosed NPC should be evaluated, particularly when they are combined with CT or RT.

[Radioresistant subline of human glioma cell line MGR2R induced by repeated high dose X-ray irradiation].

BACKGROUND & OBJECTIVE: Radiotherapy is one of the most important adjuvant treatments for patients with malignant glioma, but radiosensitivities of gliomas are widely various. This study was to induce human glioma cell line MGR2 to become a stable radioresistant cell subline, and investigate the mechanisms of radioresistance. METHODS: Human glioma cell line MGR2, with survival fraction of 2 Gy (SF(2)) of 0.18+/-0.05, was irradiated by intermittent high dose X-ray (2 Gy for 3 times, 5 Gy for 2 times). After each irradiation, the cells were cultured for 5 to 8 weeks and received irradiation again. The whole process of irradiation and culture lasted for 11 months. The cells derived from MGR2 were obtained and named MGR2R (MGR2 radiation induction). Double times of MGR2 and MGR2R cells were determined by MTT assay. Dose-survival curves, radiobiological parameters and SF2 were determined by colony-forming assay and line-quadratic model. The variation of their cell cycles was investigated by flow cytometry and cell cycle synchronization of serum-starvation. RESULTS: The double time of MGR2 cells was 3.6 days, while that of MGR2R cells was 4.0 days. The growth rate of MGR2R cells was slower than that of MGR2 cells. Using colony-forming assay and line-quadratic model, the parameters of MGR2 and MGR2R were obtained. The alpha values of MGR2 and MGR2R were 0.447 and 0.089 (t=4.524, P=0.011), the beta values were 0.177 and 0.141 (t=1.562, P=0.193), and the SF(2) were 0.208 and 0.478 (t=-6.062, P=0.040), respectively. The radioresistance of MGR2R cells was stronger than that of MGR2 cells. The distribution of cell cycle in MGR2 cells after synchronization were 54.8% in G(1) phase, 30.9% in S phase, and 14.3% in G(2) phase; 24 h after loss of synchronization, the distribution of cell cycle were 35.9% in G(1) phase, 51.2% in S phase, and 12.8% in G(2) phase. The distribution of cell cycle in MGR2R cells after synchronization were 55.7% in G(1) phase, 27.8% in S phase, and 16.6% in G(2) phase; 24 h after loss of synchronization, the distribution of cell cycle were 56.4% in G1 phase, 26.7% in S phase, and 16.9% in G(2) phase. MGR2R cells appeared G(2) phase arrest before synchronization, and G1 phase arrest after loss of synchronization. CONCLUSIONS: After intermittent high dose X-ray irradiation, radiosensitive cell line MGR2 has been induced to be relatively radioresistant (MGR2R). MGR2R cells grow slower and have G(1) phase and G(2) phase arrest which might relate to its radioresistance.

[Individualized therapy and outcomes of microsurgery, radiotherapy, and chemotherapy for astrocytoma].

BACKGROUND & OBJECTIVE: Astrocytomas, constitute about 75% of neuroepithelial tumors, is one of the most common primary tumors in central nervous system with fairly high incidence and poor prognosis. Individualized multimodality is the hope for improving prognosis of patients with astrocytoma. This study was designed to investigate the efficiency of individualized treatment of microsurgery, radiotherapy, and chemotherapy for 62 patients with astrocytoma. METHODS: Sixty-two patients with astrocytoma in study group were treated with individualized multimodality of microsurgery, postoperative radiotherapy, and/or postoperative chemotherapy according to in vitro sensitivity assay. After microsurgery, 59 patients accepted radiotherapy, 46 patients received chemotherapy. Fifty patients with astrocytoma in control group were treated with conventional treatment of surgery, chemotherapy, and radiotherapy. After surgery, 31 patients received radiotherapy following by BCNU chemotherapy, while 19 patients accepted BCNU chemotherapy following radiotherapy. Pathologic diagnosis of patients in study group were 19 cases of grade, 32 cases of grade III, and 11 cases of grade IV; in control group were 13 cases of grade II, 28 cases of grade III, and 9 cases of grade IV. Mean follow-up time were 25.8 months, and the outcome was evaluated by MRI, KPS, and survival rate. RESULTS: Tumor total resection rate in study group was 67.7%, while that in control group was 58.0%. There was no significant difference of KPS and survival rate in patients with low-grade astrocytoma between 2 groups, while the outcome of patients with malignant astrocytoma was significantly improved by individualized treatment. In study group, 2-year expectant survival rate of patients with astrocytoma of grade III, and grade IV were 93.7%, and 36.3%, while in control group were 67.5%, and 22.2% (P< 0.05). In glioblastoma patients, median survival time of study group was 18.68 months, while that of control group was 12.83 months (P< 0.01). CONCLUSION: Individualized microsurgery may improve the total resection of astrocytoma, and benefit to postoperative treatment.Individualized radiotherapy/chemotherapy may prevent patients from some complications. Individualized management may improve prognosis of patients with astrocytoma, particularly malignant astrocytoma.