Efficacy of concurrent chemoradiotherapy alone for loco-regionally advanced nasopharyngeal carcinoma: long-term follow-up analysis.

BACKGROUND: To analysis the clinical outcomes of concurrent chemoradiotherapy (CCRT) alone based on 10-year results for loco-regionally advanced nasopharyngeal carcinoma (LANPC), so as to provide evidence for individualized treatment strategy and designing appropriate clinical trial for different risk LANPC patients. METHODS: Consecutive patients with stage III-IVa (AJCC/UICC 8th) were enrolled in this study. All patients received radical intensity-modulated radiotherapy (IMRT) and concurrent cisplatin chemotherapy (CDDP). The hazard ratios (HRs) of death risk in patients with T3N0 was used as baseline, relative HRs were calculated by a Cox proportional hazard model to classify different death risk patients. Survival curves for the time-to-event endpoints were analyzed by the Kaplan-Meier method and compared using the log-rank test. All statistical tests were conducted at a two-sided level of significance of 0.05. RESULTS: A total of 456 eligible patients were included. With 12-year median follow-up, 10-year overall survival (OS) was 76%. 10-year loco-regionally failure-free survival (LR-FFS), distant failure-free survival (D-FFS) and failure-free survival (FFS) were 72%, 73% and 70%, respectively. Based on the relative hazard ratios (HRs) of death risk, LANPC patients were classified into 3 subgroups, low-risk group (T1-2N2 and T3N0-1) contained 244 patients with HR < 2; medium-risk group (T3N2 and T4N0-1) contained 140 patients with HR of 2 - 5; high-risk group (T4N2 and T1-4N3) contained 72 patients with HR > 5. The 10-year OS for patients in low-, medium-, and high-risk group were 86%, 71% and 52%, respectively. Significantly differences of OS rates were found between each of the two groups (low-risk group vs. medium-risk group, P < 0.001; low-risk group vs. high-risk group, P < 0.001; and medium-risk group vs. high-risk group, P = 0.002, respectively). Grade 3-4 late toxicities included deafness/otitis (9%), xerostomia (4%), temporal lobe injury (5%), cranial neuropathy (4%), peripheral neuropathy (2%), soft tissue damage (2%) and trismus (1%). CONCLUSIONS: Our classification criteria demonstrated that significant heterogeneity in death risk among TN substages for LANPC patients. IMRT plus CDDP alone maybe suitable for low-risk LANPC (T1-2N2 or T3N0-1), but not for medium- and high-risk patients. These prognostic groupings provide a practicable anatomic foundation to guide individualized treatment and select optimal targeting in the future clinical trials.

Increased MCL-1 synthesis promotes irradiation-induced nasopharyngeal carcinoma radioresistance via regulation of the ROS/AKT loop.

Worldwide, nasopharyngeal carcinoma (NPC) is a rare head and neck cancer; however, it is a common malignancy in southern China. Radiotherapy is the most important treatment strategy for NPC. However, although radiotherapy is a strong tool to kill cancer cells, paradoxically it also promotes aggressive phenotypes. Therefore, we mimicked the treatment process in NPC cells in vitro. Upon exposure to radiation, a subpopulation of NPC cells gradually developed resistance to radiation and displayed cancer stem-cell characteristics. Radiation-induced stemness largely depends on the accumulation of the antiapoptotic myeloid cell leukemia 1 (MCL-1) protein. Upregulated MCL-1 levels were caused by increased stability and more importantly, enhanced protein synthesis. We showed that repeated ionizing radiation resulted in persistently enhanced reactive oxygen species (ROS) production at a higher basal level, further promoting protein kinase B (AKT) signaling activation. Intracellular ROS and AKT activation form a positive feedback loop in the process of MCL-1 protein synthesis, which in turn induces stemness and radioresistance. AKT/MCL-1 axis inhibition attenuated radiation-induced resistance, providing a potential target to reverse radiation therapy-induced radioresistance.

Whole-body hyperthermia combined with chemotherapy and intensity-modulated radiotherapy for treatment of advanced nasopharyngeal carcinoma: a retrospective study with propensity score matching.

BACKGROUND: Several studies have reported the combination of intracavity or cervical lymph node hyperthermia with chemoradiotherapy (CRT) to improve clinical outcomes in nasopharyngeal carcinoma (NPC), but the combination with whole-body hyperthermia (WBH) for treating NPC is unexplored. We aimed to assess the efficacy of the combination of radiotherapy, chemotherapy and WBH in patients with locoregionally advanced NPC. METHODS: Between July 2008 and November 2012, 239 newly diagnosed NPC patients were enrolled in a pre-propensity score-matched cohort, including 193 patients who received CRT (CRT group) and 46 who underwent CRT with WBH (HCRT group). The feasibility and clinical outcomes of both groups were evaluated and toxicities assessed. Survival rates were assessed using the Kaplan-Meier method, log-rank test and Cox regression. RESULTS: Following propensity score matching, 46 patients from each group were included. The 5-year overall survival (OS) rates were 65.2% in the CRT group and 80.3% in the HCRT group (p=.027). In contrast, the other survival outcomes at 5 years were similar between the groups: locoregional recurrence-free survival (LRRFS), 74.7% vs. 87.6% (p=.152); distant metastasis-free survival (DMFS), 67.4% vs. 77.9% (p=.125); and progression-free survival (PFS), 53.1% vs. 69.2% (p=.115). In the multivariate analyses, the only two independent predictors of OS were clinical stage and HCRT. CONCLUSIONS: These results suggest that WBH, when combined with CRT, can improve the OS of patients with advanced NPC.

Effectiveness and safety of different amifostine regimens: Preliminary results of a phase II multicenter randomized controlled trial.

OBJECTIVE: The radioprotective effects of amifostine remain uncertain in patients with nasopharyngeal carcinoma (NPC), and adverse effects and cost limit generalization of its classical everyday regimen. This phase II multicenter randomized controlled trial aimed to explore whether amifostine could ameliorate the toxicities of NPC patients in the era of intensity-modulated radiotherapy (IMRT), and to compare different regimens of amifostine on effectiveness and safety. METHODS: Patients with stage I-IVB NPC were involved prospectively from January 1st, 2013. All patients received radical treatment based on IMRT. After a randomization stratified by their stage, these patients were allocated into 3 groups: the group treated without amifostine, the group treated with the everyday regimen of amifostine, and the group treated with the every-other-day regimen. The 3 groups of patients were compared on radiotherapy-related acute toxicities, treatment effects of NPC, and amifostine-related complications. This trial was registered on the clinicaltrials.gov (ID: NCT01762514). RESULTS: Until August 31st, 2017, totally 187 patients completed experimental intervention. Only amifostine of everyday regimen appeared to reduce the patient proportion of mucositis (79.1% vs. 96.8%, P=0.002). Hypocalcemia was less common in patients treated without amifostine than in those treated with amifostine (22.6% vs. 53.4% vs. 41.8%, P=0.002). Neither complete remission rates nor the survivals were affected by amifostine. CONCLUSIONS: Amifostine of everyday regimen could reduce mucositis in NPC patients who received IMRT, though it also had the possibility to cause more hypocalcemia.

RASSF6-mediated inhibition of Mcl-1 through JNK activation improves the anti-tumor effects of sorafenib in renal cell carcinoma.

Ras association domain family member 6 (RASSF6) has been shown to act as a tumor suppressor and predictor of poor prognosis in renal cell carcinoma (RCC). However, little is known about the effects of RASSF6 on sorafenib resistance or the underlying mechanism. Here, we show that RASSF6 expression positively correlates with sorafenib sensitivity in RCC cells and human samples. Stable ectopic overexpression of RASSF6 in RCC cell lines reduces resistance to sorafenib in vitro and in vivo. At a molecular level, RASSF6 activates the JNK signaling pathway, which further contributes to Mcl-1 inhibition. Suppression of the JNK pathway can partially restore Mcl-1 expression and sorafenib resistance. Together, these findings suggest that RASSF6 inhibits sorafenib resistance by repressing Mcl-1 through the JNK-dependent pathway. RASSF6 may serve as a novel regulator for sorafenib therapy in RCC.

Enhanced cytotoxic effect of low doses of metformin combined with ionizing radiation on hepatoma cells via ATP deprivation and inhibition of DNA repair.

Metformin, one of the most widely used antidiabetic drugs, has recently been associated with potential antitumorigenic effects. In this study, we evaluated the possible cytotoxic impact of combined low doses of metformin and ionizing radiation (IR) on 2 human hepatoma cell lines. The cytotoxic effect of metformin combined with IR was subsequently determined by clonogenic survival and cell cycle assays, assessment of mitochondrial complex I and lactate dehydrogenase (LDH) activity, measurement of cellular adenosine triphosphate (ATP) levels, comet assay and analyses of the formation and disappearance of phosphorylated histone H2AX (γ-H2AX) protein. The combination of metformin and IR caused a much stronger cytotoxicity than the treatment with metformin or IR alone, leading to an ~80% decrease in cell viability and ~35% increase in the accumulation of cells in the G2/M phase of the cell cycle in the 2 hepatoma cell lines. In addition, a reduction in mitochondrial complex I activity (~70%) and a significant increase in LDH activity, as well as lactate production were observed in the cells exposed to metformin. Interestingly, a severe depletion in ATP, increased olive tail moment and the delayed disappearance of γ-H2AX expression were detected in the hepatoma cells treated by metformin plus IR. These findings show that the combination of a low concentration of metformin and IR results in the considerable enhancement of cytotoxic effects in human hepatoma cell lines, leading to decreased DNA repair by reducing ATP production. The data provided in this study may elucidate the remarkable efficiency of this combination treatment and suggest that metformin may be used as a potential adjunct to the radiotherapy of hepatocellular carcinoma.

Effect of hyperthermia on invasion ability and TGF-ß1 expression of breast carcinoma MCF-7 cells.

The present study aimed to investigate heating-induced alterations of breast cancer cell invasion abilities and the potential mechanisms associated with TGF-ß1 expression. MCF-7 cells were heated at 43, 45, 47 and 37 °C for 30 min. In vitro cell invasion ability was evaluated by matrigel invasion assay. The activity of matrix metalloproteinase (MMP)-2/9 was investigated by gelatin zymographic assays. Expression of vascular endothelial growth factor (VEGF) and transforming growth factor-ß1 (TGF-ß1) was investigated by immunocytochemistry and RT-PCR. Apoptosis was analysed by flow-cytometry. The invasive potential of MCF-7 cells was reduced by heating, and MMP-2/9 secretion and enzymatic activity were suppressed. Furthermore, VEGF and TGF-ß1 mRNA and proteins were suppressed by hyperthermia. These results suggest that down-regulation of the expression of TGF-ß1, EGF and MMPs by hyperthermia probably accounts for the inhibition of the invasive abilities of MCF-7 cells.