Survival benefit of induction chemotherapy for locally advanced nasopharyngeal carcinoma: prognosis based on a new risk estimation model.

BACKGROUND: Although the National Comprehensive Cancer Network (NCCN) Guidelines recommend CCRT+AC and IC + CCRT as level 2A evidence for treatment of the locoregionally advanced NPC (II-IVa), IC + CCRT+AC could also be an alternative but it is seldom used because of the low completion rates. This article aimed to compare the effectiveness of the three radiotherapy regimens using a large-scale retrospective study. METHODS: This retrospective single center analysis enrolled 1812 diagnosed NPC patients at Nanfang Hospital from January 2005 to December 2015 and only 729 patients met the inclusion criteria and were analyzed. Patients without distant metastasis, age of 18-70 years, Karnofsky scores of at least 70,stage III-IVb, and adequate adequate bone marrow, liver and renal function. Were enrolled. Adverse events and other categorical variables were compared by Pearson chi-square test or Fishier exact test. Time-to-event data were described with the Kaplan-Meier curves, time-to-event intervals compared with the log-rank test. We did multivariable analyses with the Cox proportional hazards model to test the independent signifi cance of diff erent factors. Cox proportional hazards model was used to estimate the ß regression coeffi cient, p value, and hazard ratio and its 95% CI for each of the selected risk predictors. RESULTS: The median follow-up time was 47 months. Kaplan-Meier analyses revealed no significant differences among three groups in 3-year failure-free survival (FFS, P = 0.225), 3-year overall survival (OS, P = 0.992), 3-year locoregional failure-free survival (LFFS, P = 0.549), and 3-year distant failure-free survival (DFFS, P = 0.174). Stratified survival analysis based on the risk scoring model revealed no differences in FFS, OS, LFFS, and DFFS between IC + CCRT and CCRT+AC groups for low-risk patients, however, the 3-year OS (88.3% vs. 77.6%, P = 0.049) and 3-year DFFS (84.0% vs.66.8%, P = 0.032) were respectively significantly better in IC + CCRT group compared with CCRT+AC group for high-risk patients. CONCLUSIONS: Compared with CCRT+AC, IC + CCRT lowers distant metastasis rate and improves OS among patients with locally advanced NPC in high risk group.

Long-term monitoring of dynamic changes in plasma EBV DNA for improved prognosis prediction of nasopharyngeal carcinoma.

BACKGROUND: This study was performed to investigate whether long-term monitoring of dynamic changes in plasma Epstein-Barr virus (EBV) DNA could improve prognosis prediction of nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: About 1077 nonmetastatic NPC patients were recruited to retrospectively analyze the prognostic value of plasma EBV DNA load pretreatment and 3, 12, 24, and 36 months posttreatment. We also examined the prognostic value of dynamic changes in plasma EBV DNA at various time points. RESULTS: Patients with plasma EBV DNA load above optimal pre- and posttreatment cut-offs had significantly worse five-year progression-free survival, distant metastasis-free survival, locoregional relapse-free survival, and overall survival (OS) at all-time points, excluding only OS at 36 months posttreatment due to limited mortalities. Patients with persistently undetectable plasma EBV DNA at the first four time points had the best prognosis, followed by those with positive detection pretreatment and consistently negative detection posttreatment, those with negative detection pretreatment and positive detection at one time point posttreatment, and those with positive detection pretreatment and at one time point posttreatment, whereas patients with positive detection at ≥2 time points posttreatment had the worst prognosis. Cox proportional hazard models identified the dynamic change pattern as an independent prognostic factor, and receiver operating characteristic curve analysis demonstrated that the dynamic change at four time point was more valuable than any single time point for predicting disease progression, distant metastasis, locoregional relapse, and mortality. CONCLUSIONS: Dynamic changes in plasma EBV DNA pre- and posttreatment could predict the long-term survival outcome and provide accurate risk stratification in NPC.

EZH2 promotes angiogenesis through inhibition of miR-1/Endothelin-1 axis in nasopharyngeal carcinoma.

Emerging evidence clearly indicates that EZH2 plays a crucial role in tumor angiogenesis. However, the role of EZH2 in angiogenesis is still unknown in nasopharyngeal carcinoma (NPC). We here showed that the elevated EZH2 level was closely associated with an aggressive and poor prognostic phenotype, and was positively correlated with microvessel density (MVD) in NPC tissues. Functional studies showed that EZH2 upregulation promoted cell proliferation, migration and tubule formation of endothelial cells, and knockdown of EZH2 suppressed tumor growth, metastasis and angiogenesis in vivo. Mechanistic investigations revealed that EZH2 inhibited miR-1 transcription via promoter binding activity, leading to enhanced expression of Endothelin-1 (ET-1) which is suppressed by miR-1 targeting of ET-1 3'UTR. Furthermore, knockdown of EZH2 or overexpression of miR-1 exerted anti-angiogenic effect on NPC cells. More importantly, the neutralizing antibody against ET-1 significantly abrogated the pro-angiogenic effect of EZH2, and forced expression of ET-1 rescued the anti-angiogenic effect induced by EZH2 knockdown. In clinical specimens, ET-1 was widely overexpressed and associated with clinical stage and MVD. Taken together, our results identify a novel signaling pathway involved in NPC angiogenesis, and also suggest that EZH2-miR-1-ET-1 axis represents multiple potential therapeutic targets for NPC.

Diagnostic and prognostic value of plasma microRNA deregulation in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is uncommon worldwide but often highly invasive in late stages. Due to its special location and lack of specific symptoms, NPC is hardly detected in regular medical examination at the beginning. Development of sensitive and specific biomarkers should help to save lives against this type of disease. In the present report, we investigated the value of plasma miRNAs for diagnosis and prognosis of NPC. Using candidate approach, we selected 21 miRNAs from literature to compare their expression levels in the plasma of NPC patients and controls. As a result, 5 miRNAs showed diagnostic potentials (P<0.01). Among them, miR-16, -21, -24, and -155 had increased levels in NPC patients, whereas the level of miR-378 was decreased. There was a negative correlation between plasma miRNA expression and cancer progression, where miR-21 was statistically significant in T and N staging and miR-16 and 24 were significant in N staging only. Combination of miR-16, -21, -24, -155, and -378 gives 87.7% of sensitivity and 82.0% of specificity for NPC diagnosis. Without miR-16, combination of the rest 4 miRNAs gives the same sensitivity but a slightly reduced specificity. After treatment, all 5 miRNAs were somewhat back to normal levels in patients without cancer recurrence but the prognostic value was not statistically significant. In conclusion, plasma miRNA expression is a useful biomarker for NPC diagnosis but not for its prognosis. More importantly, it is simple, effective, and non-invasive. Combination of several plasma miRNAs can increase both NPC diagnostic sensitivity and specificity.

[Efficiency comparison between PET/CT and conventional work-up for evaluating distant metastasis of nasopharyngeal carcinoma].

OBJECTIVE: The large sample retrospective cohort study were used to compare the diagnostic efficiency of PET/CT with conventional work-up (CWU) for evaluating nasopharyngeal carcinoma (NPC) distant metastasis. METHOD: Five hundred and fourteen patients with NPC were divided into PET/CT group and CWU group according the method of detecting distant metastasis. Chest film, abdominal ultrasonography, and bone scan were used in CWU group. Then the diagnostic efficiency of the two groups was compared. RESULT: Two hundred and sixteen patints were enrolled in PET/CT group and two hundred and nineteen-eight ones in CWU group. There were 28 out of 412 suspicious patients in CWU group were confirmed, another 3 patients confirmed without positive findings, compared with PET/CT group that all 32 suspicious patients were confirmed. The sensitivity and specificity of PET/CT were 100.0% (32/32) and 100.0% (184/184), as compared to 90.3% (28/31) and 94.8% (253/267) with CWU respectively, while there was no statistical significance. Further research found out that the percentage of patients with multiple distant metastatic sites and multiple organ metastases was higher in PET/CT group (P < 0.05), and similarly of patients with distant metastasis in N2-3 stages (P < 0.01). CONCLUSION: Our results suggest that PET/CT appears to be slightly superior to conventional work-up in assessment of distant metastasis in NPC patients, but CWU is still a cheap and practical method.

[Effects of enhancer of zeste homolog (EZH2) downregulation on the proliferation and invasion of nasopharyngeal carcinoma cell and the possible mechanisms].

OBJECTIVE: To investigate the effects of the enhancer of zeste homolog 2 (EZH2) gene on cell growth and invasion of the nasopharyngeal carcinoma (NPC). METHODS: Recombinant lentivirus vector for shRNA delivery of EZH2 was constructed and transfected into 293FT cells. After collecting the viral particles, the NPC cell line 5-8F cells were transfected. The effects of EZH2 silence on cell proliferation and cell cycle were detected using MTT assay, plate colony formation assay and flow cytometry. The migration and invasion of 5-8F cells were determined by wound healing assay and matrigel invasion assay, respectively. The expressions of EZH2 and epithelial-mesenchymal transition (EMT)-related markers at mRNA and protein levels were examined by real-time PCR and Western blot respectively. RESULTS: The expressions of EZH2 mRNA and protein in the transfected 5-8F cells were obviously reduced. MTT assay showed that EZH2 downregulation significantly inhibited the growth of 5-8F/shEZH2 cells (P < 0.001). Colony formation rate (84.44%) of 5-8F/shEZH2 cells was lower than control (31.56%, P = 0.001). Cell cycle analysis showed that most 5-8F/shEZH2 cells were arrested in G0/G1 phase, with a very low ratio of cells in S phase. Wound healing assay indicated that the migration ability of cells silencing EZH2 decreased significantly, and the 48-hour relative migration distance of 5-8F/ShEZH2 cells and control cells was 0.58 ± 0.05, and 0.81 ± 0.02, respectively (P < 0.000). Matrigel invasion assay, showed the invasive capacity of cells silencing EZH2 was significantly inhibited, with less penetrating cells (72.23 ± 4.08) compared to control (150.95 ± 16.27), P < 0.000. The mRNA expressions of epithelial markers E-cadherin and Keratin 18 in the cells silencing EZH2 increased by 177% and 158% respectively, and the mRNA expressions of mesenchymal markers ß-catenin and N-cadherin decreased by 18.04% and 41.18% respectively. Similar results also were obtained with Western blot analysis. CONCLUSION: EZH2 significantly enhanced the proliferation and invasion of nasopharyngeal carcinoma cells in vitro, which might be mediated by inducing EMT.