Late-stage Nasopharyngeal Carcinoma Research Articles

Circulating mRNA Expression of VEGF, PTEN, and SOCS1 as Potential Prognostic Predictor for Nasopharyngeal Carcinoma Progression.

The molecular mechanisms underlying nasopharyngeal carcinoma (NPC) progression remain poorly understood. In particular, the roles of circulating mRNAs encoding key regulatory proteins have yet to be explored. This study aimed to identify NPC-associated expression signatures of circulating VEGF, PTEN, and SOCS1 mRNAs and their potential as biomarkers. A case-control study was conducted comprising 160 nasopharyngeal carcinoma (NPC) patients and 80 controls, from whom peripheral blood samples. Total RNA was extracted and the levels of VEGF, PTEN, and SOCS1 mRNAs were quantified using reverse transcription quantitative PCR (RT-qPCR). Relative expression was calculated using the 2-ΔΔCt method. Bioinformatic analyses, including GeneMANIA, Gene Ontology (GO), and KEGG pathway analysis, were performed to predict the functional roles and interactions of these mRNAs. We identified significantly increased circulating VEGF mRNA in lymph node metastases (1.66-fold, p<0.05) and elevated SOCS1 mRNA in late-stage NPC (20-fold, p<0.05). PTEN mRNA was reduced 4.26-fold in NPC patients. These data suggest that circulating VEGF, PTEN, and SOCS1 mRNAs represent signatures of NPC progression and can potentially be biomarkers. Network analyses implicate these mRNAs in mechanisms enabling NPC pathogenesis. Our study reveals NPC-associated expression changes of circulating VEGF, PTEN, and SOCS1 mRNAs. These molecular signatures may serve as biomarkers during NPC progression and provide insights into underlying mechanisms. Further validation of their utility as prognostic indicators of NPC is warranted.

Small extracellular vesicle CA1 as a promising diagnostic biomarker for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), a malignant cancer originating from the epithelial cells of the nasopharynx, presents diagnostic challenges with current methods such as plasma Epstein-Barr virus (EBV) DNA testing showing limited efficacy. This study focused on identifying small extracellular vesicle (sEV) proteins as potential noninvasive biomarkers to enhance NPC diagnostic accuracy. We isolated sEVs from plasma and utilized 4D label-free proteomics to identify differentially expressed proteins (DEPs) among healthy controls (NC = 10), early-stage NPC (E-NPC = 10), and late-stage NPC (L-NPC = 10). Eighteen sEV proteins were identified as potential biomarkers. Subsequently, parallel reaction monitoring (PRM) proteomic analysis preliminarily confirmed sEV carbonic anhydrase 1 (CA1) as a highly promising biomarker for NPC, particularly in early-stage diagnosis (NC = 15; E-NPC = 10; L-NPC = 15). To facilitate this, we developed an automated, high-throughput and highly sensitive CA1 immune-chemiluminescence chip technology characterized by a broad linear detection range and robust controls. Further validation in an independent retrospective cohort (NC = 89; E-NPC = 39; L-NPC = 172) using this technology confirmed sEV CA1 as a reliable diagnostic biomarker for NPC (AUC = 0.9809) and E-NPC (AUC = 0.9893), independent of EBV-DNA testing. Notably, sEV CA1 exhibited superior diagnostic performance compared to EBV-DNA, with a significant incremental net reclassification improvement of 27.61 % for NPC and 72.11 % for E-NPC detection. Thus, this study identifies sEV CA1 as an innovative diagnostic biomarker for NPC and E-NPC independent of EBV-DNA. Additionally, it establishes an immune-chemiluminescence chip technology for the detection of sEV CA1 protein, paving the way for further validation and clinical application.

PQR309, a dual PI3K/mTOR inhibitor, synergizes with gemcitabine by impairing the GSK-3β and STAT3/HSP60 signaling pathways to treat nasopharyngeal carcinoma

End-stage nasopharyngeal carcinoma (NPC) has unsatisfactory survival. The limited benefit of chemotherapy and the scarcity of targeted drugs are major challenges in NPC. New approaches to treat late-stage NPC are urgently required. In this study, we explored whether the dual PI3K/mTOR inhibitor, PQR309, exerted a favorable antineoplastic effect and sensitized the response to gemcitabine in NPC. We observed that PI3K expression was positive and elevated in 14 NPC cell lines compared with that in normal nasopharygeal cell lines. Patients with NPC with higher PI3K levels displayed poorer prognosis. We subsequently showed that PQR309 alone effectively decreased the viability, invasiveness, and migratory capability of NPC cells and neoplasm development in mice xenograft models, and dose-dependently induced apoptosis. More importantly, PQR309 remarkably strengthened the anti-NPC function of gemcitabine both in vivo and in vitro. Mechanistically, PQR309 sensitized NPC to gemcitabine by increasing caspase pathway-dependent apoptosis, blocking GSK-3β and STAT3/HSP60 signaling, and ablating epithelial-mesenchyme transition. Thus, targeting PI3K/mTOR using PQR309 might represent a treatment option to promote the response to gemcitabine in NPC, and provides a theoretical foundation for the study of targeted drugs combined with chemotherapy for NPC.

EBV abortive lytic cycle promotes nasopharyngeal carcinoma progression through recruiting monocytes and regulating their directed differentiation.

Epstein-Barr virus (EBV) is associated with several types of human cancer including nasopharyngeal carcinoma (NPC). The activation of EBV to the lytic cycle has been observed in advanced NPC and is believed to contribute to late-stage NPC development. However, how EBV lytic cycle promotes NPC progression remains elusive. Analysis of clinical NPC samples indicated that EBV reactivation and immunosuppression were found in advanced NPC samples, as well as abnormal angiogenesis and invasiveness. To investigate the role of the EBV lytic cycle in tumor development, we established a system that consists of two NPC cell lines, respectively, in EBV abortive lytic cycle and latency. In a comparative analysis using this system, we found that the NPC cell line in EBV abortive lytic cycle exhibited the superior chemotactic capacity to recruit monocytes and polarized their differentiation toward tumor-associated macrophage (TAM)-like phenotype and away from DCs, compared to EBV-negative or EBV-latency NPC cells. EBV-encoded transcription activator ZTA is responsible for regulating monocyte chemotaxis and TAM phenotype by up-regulating the expression of GM-CSF, IL-8, and GRO-α. As a result, TAM induced by EBV abortive lytic cycle promotes NPC angiogenesis, invasion, and migration. Overall, this study elucidated the role of the EBV lytic life cycle in the late development of NPC and revealed a mechanism underlying the ZTA-mediated establishment of the tumor microenvironment (TME) that promotes NPC late-stage progression.

Diagnosis of nasopharyngeal carcinoma with convolutional neural network on narrowband imaging

Objective:To evaluate the diagnostic accuracy of the convolutional neural network（CNN） in diagnosing nasopharyngeal carcinoma using endoscopic narrowband imaging. Methods:A total of 834 cases with nasopharyngeal lesions were collected from the People's Hospital of Guangxi Zhuang Autonomous Region between 2014 and 2016. We trained the DenseNet201 model to classify the endoscopic images, evaluated its performance using the test dataset, and compared the results with those of two independent endoscopic experts. Results:The area under the ROC curve of the CNN in diagnosing nasopharyngeal carcinoma was 0.98. The sensitivity and specificity of the CNN were 91.90% and 94.69%, respectively. The sensitivity of the two expert-based assessment was 92.08% and 91.06%, respectively, and the specificity was 95.58% and 92.79%, respectively. There was no significant difference between the diagnostic accuracy of CNN and the expert-based assessment （P=0.282, P=0.085）. Moreover, there was no significant difference in the accuracy in discriminating early-stage and late-stage nasopharyngeal carcinoma（P=0.382）. The CNN model could rapidly distinguish nasopharyngeal carcinoma from benign lesions, with an image recognition time of 0.1 s/piece. Conclusion:The CNN model can quickly distinguish nasopharyngeal carcinoma from benign nasopharyngeal lesions, which can aid endoscopists in diagnosing nasopharyngeal lesions and reduce the rate of nasopharyngeal biopsy.

ZBTB7A governs 2-DG-inhibited glycolysis by regulating GLUT1 in nasopharyngeal carcinoma

Our previous studies suggested a potential interaction between the POK erythroid myeloid ontogenic factor ZBTB7A and glucose transporter 1 (GLUT1) in nasopharyngeal carcinoma (NPC). This study was designed to confirm the interaction and further evaluate the precise mechanism by which ZBTB7A and GLUT1 regulate NPC development. The binding sites between ZBTB7A and the promoter of GLUT1 were predicted by bioinformatics. Gene expression was measured by quantitative real-time polymerase chain reaction (qPCR), western blotting, and immunohistochemistry. The activities of key glycolysis enzymes, including hexokinase (HK), pyruvate kinase (PK), lactate dehydrogenase (LDH), and lactate, were detected using specific enzyme-linked immunosorbent assay kits. The connection between ZBTB7A and GLUT1 was analyzed by dual-luciferase reporter assay and chromatin immunoprecipitation–qPCR. The vitality, proliferation, and tumorigenicity of the cells expressing different levels of ZBTB7A were tested by adding the glycolysis inhibitor 2-deoxy-D-glucose (2-DG), followed by MTT, colorimetric focus forming, and xenograft assays, respectively. Our results showed that high expression of GLUT1 was associated with late-stage NPC. After constructing stably transfected cells with lentiviruses, ZBTB7A was effectively knocked down in 5-8F cells (RNAi-5-8F) and overexpressed in 6-10B cells (ZBTB7A-6-10B). The up- or downregulation of GLUT1 secondary to ZBTB7A changes was also limited. The vitality and proliferation of the cells expressing low ZBTB7A were notably blocked by 2-DG. The cells expressing high ZBTB7A were not very sensitive to 2-DG. The growth of RNAi-5-8F xenografts was strongly suppressed by 2-DG. The activities of HK, PK, and LDH were suppressed by 2-DG in the cells expressing low ZBTB7A. RNAi-5-8F cells had the lowest 2-DG-induced lactate production. ZBTB7A directly suppressed the promoter region of GLUT1 to regulate GLUT1 expression. Thus, ZBTB7A controls the 2-DG-induced inhibition of glycolysis by affecting GLUT1.

Diagnostic and Prognostic Indications of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a disease that is highly associated with the latent infection of Epstein–Barr virus. The absence of obvious clinical signs at the early stage of the disease has made early diagnosis practically impossible, thereby promoting the establishment and progression of the disease. To enhance the stride for a reliable and less invasive tool for the diagnosis and prognosis of NPC, we synopsize biomarkers belonging to the two most implicated biological domains (oncogenes and tumor suppressors) in NPC disease. Since no single biomarker is sufficient for diagnosis and prognosis, coupled with the fact that the known established methods such as methylation-specific polymerase chain reaction (PCR), multiplex methylation-specific PCR, microarray assays, etc., can only accommodate a few biomarkers, we propose a 10-biomarker panel (KIT, LMP1, PIKC3A, miR-141, and miR-18a/b (oncogenic) and p16, RASSF1A, DAP-kinase, miR-9, and miR-26a (tumor suppressors)) based on their diagnostic and prognostic values. This marker set could be explored in a multilevel or single unified assay for the diagnosis and prognosis of NPC. If carefully harnessed and standardized, it is hoped that the proposed marker set would help transform the diagnostic and prognostic realm of NPC, and ultimately, help prevent the life-threatening late-stage NPC disease.

Low-Dose Aspirin Use Significantly Improves the Survival of Late-stage NPC: A Propensity Score-Matched Cohort Study in Taiwan.

Background: Aspirin use has been associated with improved survival rates in various cancers. However, it remains unclear if aspirin confers a survival benefit on patients with nasopharyngeal carcinoma (NPC). The aim of this study was to assess the associations between aspirin use and survival in different stages of NPC. Methods: This is a 10-year retrospective cohort study of NPC patients. A total of 565 NPC patients were recruited after we performed a 1:4 propensity score match between aspirin users and non–users. Cox regression models with adjusted covariates were employed to evaluate factors that influence the survival rate of NPC patients. Results: The Kaplan-Meier analysis revealed that the overall survival (p < 0.0001) and disease-specific survival (p < 0.0001) rates of 180-day aspirin users increased. Increased survival rates were also observed in 180-day aspirin users with Stages III and IV, T, N1 and 2, and N3 categories. Cox regression models indicated that factors, including aspirin use (univariate: HR = 0.28, 95% CI = 0.14–0.55, p < 0.001; multivariate: HR = 0.23, 95% CI = 0.12–0.46, p < 0.001), were independent prognostic factors for survival. Conclusions: Aspirin use for more than 180 days is associated with an increased survival rate and is a positive independent prognostic factor in NPC.

Vesicle-bound EBV-BART13-3p miRNA in circulation distinguishes nasopharyngeal from other head and neck cancer and asymptomatic EBV-infections.

Cell‐free microRNA (miRNA) in biofluids released by tumors in either protein or vesicle‐bound form, represent promising minimally‐invasive cancer biomarkers. However, a highly abundant non‐tumor background in human plasma and serum complicates the discovery and detection of tumor‐selective circulating miRNAs. We performed small RNA sequencing on serum and plasma RNA from Nasopharyngeal Carcinoma (NPC) patients. Collectively, Epstein Barr virus‐encoded miRNAs, more so than endogenous miRNAs, signify presence of NPC. However, RNAseq‐based EBV miRNA profiles differ between NPC patients, suggesting inter‐tumor heterogeneity or divergent secretory characteristics. We determined with sensitive qRT‐PCR assays that EBV miRNAs BART7‐3p, BART9‐3p and BART13‐3p are actively secreted by C666.1 NPC cells bound to extracellular vesicles (EVs) and soluble ribonucleoprotein complexes. Importantly, these miRNAs are expressed in all primary NPC tumor biopsies and readily detected in nasopharyngeal brushings from both early and late‐stage NPC patients. Increased levels of BART7‐3p, BART9‐3p and particularly BART13‐3p, distinguish NPC patient sera from healthy controls. Receiver operating characteristic curve analysis using sera from endemic NPC patients, other head and neck cancers and individuals with asymptomatic EBV‐infections reveals a superior diagnostic performance of EBV miRNAs over anti‐EBNA1 IgA serology and EBV‐DNA load (AUC 0.87–0.96 vs 0.86 and 0.66 respectively). The high specificity of circulating EBV‐BART13‐3p (97%) for NPC detection is in agreement with active secretion from NPC tumor cells. We conclude EV‐bound BART13‐3p in circulation is a promising, NPC‐selective, biomarker that should be considered as part of a screening strategy to identify NPC in endemic regions.

Leukocyte telomere length associates with nasopharyngeal carcinoma risk and survival in Hong Kong Chinese.

Telomere shortening occurs as an early event in tumorigenesis. The TERT-CLPTM1L locus associates with nasopharyngeal carcinoma (NPC) risk. It remains unknown if leukocyte telomere length (LTL) associates with NPC risk and survival. The relative LTL (rLTL) was measured by quantitative-PCR in 2,996 individuals comprised of 1,284 NPC cases and 1712 matched controls. The odds ratio (OR) and 95% confidence intervals (CI) were calculated by logistic regression. The hazard ratio (HR) and 95% CI were calculated by Cox regression for survival analysis with rLTL and other clinical parameters in 1,243 NPC with a minimum follow-up period of 25 months. NPC patients had significantly shorter telomere length than controls. Shorter rLTL significantly associated with increased NPC risk, when the individuals were dichotomized into long and short telomeres based on median-split rLTL in the control group (OR=2.317; 95% CI=1.989-2.700, p=4.10×10-27 ). We observed a significant dose-response association (ptrend =3.26×10-34 ) between rLTL and NPC risk with OR being 3.555 (95% CI=2.853-4.429) for the individuals in the first quartile (shortest) compared with normal individuals in the fourth quartile (longest). A multivariate Cox regression analysis adjusted by age demonstrated an independent effect of rLTL on NPC survival for late-stage NPC patients, when the individuals were categorized into suboptimal rLTL versus the medium rLTL based on a threshold set from normal (HR=1.471, 95% CI=1.056-2.048, p=0.022). Shorter blood telomeres may be markers for higher susceptibility for NPC risk. Suboptimal rLTL may be a poor prognostic factor for advanced NPC patients, as it associates independently with poor survival.

OVOL2 in metastasis prevention in NPC

Metastasis remains a critical - and largely elusive - target in the race to prevent cancer-related deaths. Such is true in nasopharyngeal carcinoma (NPC), where the presentation or development of metastatic disease is usually fatal. In this edition of Theranostics, Qi et al. demonstrate a critical role of the zinc-finger transcription factor, OVOL2, in suppressing metastasis and maintaining an epithelial phenotype. These data add to the depth of understanding of the metastatic program in NPC, and may eventually lead to a druggable target in late-stage NPC.

Clinical outcomes of residualorrecurrent nasopharyngeal carcinoma treated with endoscopic nasopharyngectomy plus chemoradiotherapy or with chemoradiotherapy alone: a retrospective study.

BackgroundLocal residual and recurrent nasopharyngeal carcinoma (NPC) generally shows treatment failure after standard radiotherapy with or without concurrent chemotherapy. Whether endoscopic nasopharyngectomy might provide an additional therapeutic advantage remains controversial. Therefore, we retrospectively compared the clinical prognoses of patients with residual or recurrent NPC treated with endoscopic nasopharyngectomy combined with chemoradiotherapy (CRT) with those of patients treated with CRT alone.Methods and MaterialsA total of sixty-two patients with local residual or recurrent NPC were studied retrospectively: 36 patients received endoscopic nasopharyngectomy combined with CRT, whereas 26 patients who refused the surgery or had surgical contraindications received CRT alone. Serum Epstein-Barr virus (EBV) DNA levels were measured pre- and post-treatment. The differences in prognosis between the two treatment regimens and the pre- and post-treatment changes in EBV-DNA levels were analyzed.ResultsThe median follow-up time was 31 months, with a 3-year overall survival (OS) of 51.40% and a 3-year disease-free survival (DFS) of 46.86%. The surgery + CRT group had a better OS than the CRT alone group did (χ2 = 4.054, P = 0.044). The pretreatment EBV-DNA levels showed a positive correlation with the clinical staging of recurrent NPC (χ2 = 11.674, P = 0.009). Patients with negative pretreatment serum EBV-DNA levels showed a superior OS to those of patients who tested positive for EBV-DNA (>0 copy/mL) (χ2 = 9.833, P = 0.002). The post-treatment EBV-DNA levels, compared with the pretreatment levels, decreased significantly in the surgery + CRT group (Z = − 3.484, P = 0.000). In contrast, the EBV-DNA levels after CRT alone did not decrease significantly (Z = − 1.956, P = 0.051). Multivariate analysis indicated that local staging, pretreatment EBV-DNA load, and the treatment method were independent risk factors for OS. Subgroup analysis indicated that the patients who tested negative for EBV-DNA before the treatment and those who received surgery + CRT showed a better OS than those who received CRT alone.ConclusionsThe pretreatment serum EBV-DNA level was associated with disease prognosis. The combination therapy preceded by surgery can effectively decrease the copy number of EBV-DNA. Patients with local intermediate- and late-stage NPC, especially those negative for EBV-DNA, may consider opting for surgery followed by post-operative adjuvant radiotherapy or chemotherapy.

Potential factors associated with clinical stage of nasopharyngeal carcinoma at diagnosis: a case\u2013control study

BackgroundIn China, most patients with nasopharyngeal carcinoma (NPC) are diagnosed at a late stage and consequently have a poor prognosis. This study aimed to investigate potential factors associated with the clinical stage of NPC at diagnosis.MethodsData were obtained from 118 patients with early-stage NPC and 274 with late-stage NPC who were treated at Sun Yat-sen University Cancer Center between August 2014 and July 2015. Patients were individually matched by age, sex, and residence, and a conditional logistic regression model was applied to assess the associations of clinical stage at diagnosis with socioeconomic status indicators, knowledge of NPC, physical examinations, patient interval, and risk factors for NPC.ResultsAlthough knowledge of early NPC symptoms, smoking cessation, and patient interval were important factors, the number of cigarettes smoked per day, motorbike ownership, and physical examination exhibited the strongest associations with the clinical stage of NPC at diagnosis. Compared with smoking fewer than ten cigarettes a day, smoking 10–30 cigarettes [odds ratio (OR) 4.03; 95% confidence interval (CI) 1.11–14.68] or more than 30 cigarettes (OR 11.46; 95% CI 1.26–103.91) was associated with an increased risk of late diagnosis. Compared with not owning a motorbike, owning a motorbike (OR 0.38; 95% CI 0.23–0.64) was associated with early diagnosis. Subjects who underwent physical examinations were less likely to receive a late diagnosis than those who did not undergo examinations (OR 0.50; 95% CI 0.28–0.89). However, indicators of wealth were not significant factors.ConclusionsInitiatives to improve NPC patient prognosis should aim to promote knowledge about early symptoms and detection, health awareness, and accessibility to health facilities among all patients, regardless of socioeconomic status.

Prognostic value of pretreatment serum levels of lactate dehydrogenase in nonmetastatic nasopharyngeal carcinoma: single-site analysis of 601 patients in a highly endemic area.

BackgroundNumerous studies have generated promising but incomplete evidence for the prognostic value of pretreatment serum levels of lactate dehydrogenase (S-LDH) in nasopharyngeal carcinoma (NPC).MethodsPretreatment serum levels of S-LDH in 601 patients with NPC were measured before treatment, and their associations with overall survival and tumor-free survival were studied. Univariate and multivariate analysis of subgroups was used to evaluate the prognostic value of S-LDH in early-stage and late-stage NPC separately.ResultsPretreatment S-LDH levels were significantly lower in T1+2 patients than in T3+4 patients, lower in N0+1 patients than in N2+3 ones, and lower in stage I + II patients than in III + IV ones. Multivariate analysis showed that among patients with late-stage NPC, high pretreatment S-LDH levels >225 U/L were an independent predictor of poor overall survival and tumor-free survival. Among patients with early-stage NPC, pretreatment S-LDH levels >171 U/L, which overlap with the normal range, were an independent predictor of shorter overall survival and tumor-free survival.ConclusionPretreatment S-LDH levels may be a reliable biomarker for predicting the long-term prognosis of patients with early-stage or late-stage NPC.

Dosimetric difference amongst 3 techniques: TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC)

To investigate the dosimetric difference amongst TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC). Ten patients with late-stage (Stage III or IV) NPC treated with TomoTherapy or IMRT were selected for the study. Treatment plans with these 3 techniques were devised according to departmental protocol. Dosimetric parameters for organ at risk and treatment targets were compared between TomoTherapy and IMRT, TomoTherapy and RapidArc, and IMRT and RapidArc. Comparison amongst the techniques was done by statistical tests on the dosimetric parameters, total monitor unit (MU), and expected delivery time. All 3 techniques achieved similar target dose coverage. TomoTherapy achieved significantly lower doses in lens and mandible amongst the techniques. It also achieved significantly better dose conformity to the treatment targets. RapidArc achieved significantly lower dose to the eye and normal tissue, lower total MU, and less delivery time. The dosimetric advantages of the 3 techniques were identified in the treatment of late-stage NPC. This may serve as a guideline for selection of the proper technique for different clinical cases.

A prospective, randomized study comparing outcomes and toxicities of intensity-modulated radiotherapy vs. conventional two-dimensional radiotherapy for the treatment of nasopharyngeal carcinoma

Background and PurposeTo compare clinical outcomes and toxicities of two-dimensional conventional radiation therapy (2D-CRT) and intensity modulated radiation therapy (IMRT) for the treatment of nasopharyngeal carcinoma (NPC). Materials and methodsBetween July 2003 and October 2008, 616 patients with non-metastatic stage I to IVb NPC were prospectively randomized to receive 2D-CRT (n=310; mean age, 44.8±13.6years) or IMRT (n=306; mean age, 46.7±12.5years). Clinical outcomes and acute and late toxicities were determined and compared. ResultsThe 2 groups were comparable with respect to all parameters of demographics and disease characteristics (all, p>0.05). Median follow-up was 42months (range, 1–83months). The 5-year actuarial local control rate was 90.5% in the IMRT group and 84.7% in the 2D-CRT group. The local control rates were 91% for stage T3 and 81.5% for stage T4 disease in the IMRT group and 80% and 62.2% in the 2D-CRT group, respectively. The 5-year actuarial nodal relapse-free survival (NRFS) rate was 92.4% in the IMRT and 92.9% in the 2D-CRT group (p>0.05). The NRFS was 93.9% for N2 disease in the IMRT group and 91.4% in the 2D-CRT group (p=0.02). The 5-year overall survival (OS) rate was 79.6% for the IMRT group and 67.1% for the 2D-CRT group (p=0.001). When stratified for stage, a significant difference was only noted for stage III disease. In terms of radiation-induced toxicities, patients in IMRT group had significantly lower radiation-induced toxicities than those in 2D-CRT group. ConclusionIMRT provides improved local-recurrence free survival, especially in late-stage NPC patients and is associated with a lower incidence of toxicities.

The prognostic value of histological typing in nasopharyngeal carcinoma

We analyzed the relation of histological typing in late stage nasopharyngeal carcinoma (NPC) with clinical outcome and excision repair cross complementation group 1 protein (ERCC1) expression. The biopsy specimens of 259 patients with NPC were reviewed by two pathologists for classification according to 2005 WHO subtypes. The patients were of stage III to IVB and treated with radiotherapy (RT) alone or concurrent-adjuvant chemoradiotherapy (CRT). Expression of ERCC1 protein detected by immunohistochemistry on paraffin sections was correlated with the histological subtypes. There were 10 cases (3.9%) of differentiated non-keratinizing carcinoma compared with 249 cases of conventional undifferentiated carcinoma. The former exhibited more advanced squamous differentiation with 3 cases belonging to the papillary variant. The degree of ERCC1 expression was generally high compared with the median of the cohort. Clinically, the differentiated group fared poorly compared with the undifferentiated group with respect to loco-regional failure-free rate, distant failure-free rate, disease-free survival and overall survival (p≤0.05). Treatment modality of the 10 patients (5 RT, 5 CRT) was similar to the whole cohort. Contrary to general acceptance that differentiation of non-keratinizing NPC had little bearing on prognosis, we demonstrated that in endemic area differentiation in fact conferred a worse prognosis in stage III to IVB patients. There was positive correlation of differentiation with ERCC1 expression. We advocate precise histological typing of NPC in pathology report for prognostic purpose and outcome correlation.

Overexpression of cyclin E messenger ribonucleic acid in nasopharyngeal carcinoma correlates with poor prognosis

S-phase kinase-associated protein 2 is required for the degradation of p27 protein, which is a negative regulator of cyclin E/cyclin-dependent kinase 2 complex. The present study examined the expression of cyclin E, S-phase kinase-associated protein 2 and p27 protein in nasopharyngeal carcinoma. Tissue from 35 cases of nasopharyngeal carcinoma and 10 normal nasopharyngeal tissue samples underwent reverse polymerase chain reaction to detect messenger ribonucleic acid. Immunohistochemical analysis was performed on 29 nasopharyngeal tissue samples in order to detect protein expression. Messenger ribonucleic acid expression in the nasopharyngeal carcinoma tissue samples analysed indicated a 1.75-fold change in the amount of S-phase kinase-associated protein 2, a 0.34-fold change in the amount of cyclin E and a 0.31-fold change in the amount of p27 protein, compared with positive controls. High levels of cyclin E significantly correlated with late-stage nasopharyngeal carcinoma (p = 0.009) and a poor overall survival (p = 0.010). Immunohistochemical analysis indicated positive expression of S-phase kinase-associated protein 2 in 16/29 nasopharyngeal tissue samples (55 per cent), of cyclin E in 13/29 samples (45 per cent) and of p27 protein in 17/29 (59 per cent) samples. Overexpression of cyclin E messenger ribonucleic acid showed an adverse prognostic significance, correlating with an advanced stage of nasopharyngeal carcinoma and a low overall survival rate.

High frequency of common deletion (4981 bp) in mitochondrial DNA in nasopharyngeal carcinoma and its correlation with patient age and clinical stages

Mitochondrial DNA (mtDNA) has a high mutation rate due at least in part to a lack of protective histones and an inefficient DNA repair system. The most frequently change in mtDNA is the so-called Common Deletion (CD), which accumulates in patients with hetero-plasmic mtDNA mutations and in normal individuals during aging. In this study, wild type mtDNA (WT-mtDNA) and mitochondrial DNA with CD (CD-mtDNA) were quantitatively analyzed in different nasopharynx lesions. A novel type of CD-mtDNA (4981 bp) was de-tected significantly higher in nasopharyngeal carcinoma (NPC) (93%, 54/58) than in naso-pharyngitis (60%, 28/47) and the paired white blood cells (WBC) (26%, 8/31). The ratio of CD-mtDNA to WT-mtDNA in NPC (0.000625, median) was 10 times that in nasopharyngitis (0.000064, median) (P = 0.003), and was significantly higher than that in paired WBC (0.000000, median) (P = 0.000). The CD/WT-mtDNA ratio was 0.000564 (quartile range, 0.000184 - 0.000919) in late stage NPC, which was nearly 3 times the ratio in early stage NPC (0.000164, quartile range, 0.000042 - 0.000353) (P = 0.015, Mann-Whitney Test). In NPC patients with ages °› 48yrs (mean age), the ratio of CD-mtDNA to WT-mtDNA was 0.000625, which was nearly 10 times that in NPC patients with ages < 48yrs (0.000064) (P = 0.005, Mann-Whitney Test). This is the first quantitative study of CD-mtDNA mutations in NPC, which provides evidences that CD-mtDNA mutation might be involved in the devel-opment and progression of NPC.