Prospective evaluation of plasma Epstein-Barr virus DNA clearance and fluorodeoxyglucose positron emission scan in assessing early response to chemotherapy in patients with advanced or recurrent nasopharyngeal carcinoma.

BACKGROUND: Plasma Epstein-Barr virus (pEBV) DNA and fluorodeoxyglucose positron emission (PET) reflect tumour burden in advanced NPC. This study hypothesised that a dual endpoint based on assessing pEBV DNA clearance and PET response could predict early drug response. METHODS: Eligible patients underwent a computed tomography (CT) scan and dual PET-CT at baseline, a PET-CT at 4 weeks, and then a CT scan at 10 weeks after starting palliative or induction chemotherapy. Plasma EBV DNA clearance was determined. RESULTS: Fifty-eight out of 70 enrolled patients completed all imaging and 50/58 had falling pEBV DNA level, which allowed calculation of the clearance. At a median follow-up of 29.1 months, the dual endpoint (pEBV DNA clearance ≤ 10 days and > 50% drop in sum of SUVmax of target lesions) was an independent indicator of overall survival (hazard ratio (HR) = 0.135, 95% CI = 0.039 to 0.466, p = 0.0015) and progression-free survival (HR = 0.136, 95% CI = 0.048 to 0.385, p = 0002). This dual endpoint could predict subsequent response by Response Evaluation Criteria In Solid Tumours (RECIST) criteria at 10 weeks after chemotherapy. CONCLUSIONS: Early PET-CT response and pEBV DNA clearance could predict survival and subsequent response. This dual endpoint is an innovative tool for assessing early drug response.

MRI findings in patients with severe trismus following radiotherapy for nasopharyngeal carcinoma.

The aim of the study was to document MRI findings in masticator structures in patients with trismus developing after radiotherapy for nasopharyngeal carcinoma (NPC). MRI neck examinations were reviewed in 35 patients with marked trismus, defined as an interincisal gap of 25 mm or less, post-radiotherapy for NPC. Patients with trismus before treatment, infiltration of masticator structures at the time of trismus, or previous surgery involving the masticator structures were excluded. Sixteen patients had no significant abnormality in their masticator structures (46%). Nineteen patients (54%) had abnormalities comprising radiotherapy-induced masticator muscle fibrosis (n = 19), denervation atrophy of the masticator muscles secondary to mandibular nerve damage (n = 1), mandibular ramus signal abnormalities (n = 5), mandibular condyle sclerosis with or without capsular thickening (n = 5), perimasticator fibrosis extending into the masticator space (n = 3) and inflammation secondary to severe sinusitis extending into the masticator space (n = 2). Nine patients (26%) had more than one type of abnormality. Twenty-two patients (63%) had concomitant skull base osteoradionecrosis which extended into the pterygoid bases in 16 patients (45%). The presence of several MRI abnormalities in the masticator structures of patients with trismus after radiotherapy suggests that trismus is multifactorial. This study advances the understanding of mechanisms behind this debilitating side effect of radiotherapy.

Randomized phase II trial of concurrent cisplatin-radiotherapy with or without neoadjuvant docetaxel and cisplatin in advanced nasopharyngeal carcinoma.

PURPOSE: To compare the toxicities, tumor control, survival, and quality of life of nasopharyngeal cancer (NPC) patients treated with sequential neoadjuvant chemotherapy followed by concurrent cisplatin-radiotherapy (CRT) or CRT alone. PATIENTS AND METHODS: Previously untreated stage III to IVB NPC were randomly assigned to (1) neoadjuvant docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) every 3 weeks for two cycles, followed by cisplatin 40 mg/m(2)/wk concurrent with radiotherapy, or (2) CRT alone. Planned accrual was 30 patients per arm to detect 20% difference of toxicities based on 95% CIs. RESULTS: From November 2002 to November 2004, 65 eligible patients were randomly assigned to neoadjuvant chemotherapy followed by CRT (n = 34) or CRT alone (n = 31). There was a high rate of grade 3/4 neutropenia (97%) but not neutropenic fever (12%) during neoadjuvant chemotherapy. No significant differences in rates of acute toxicities were observed between the two arms during CRT. Dose intensities of concurrent cisplatin, late RT toxicities and quality of life scores were comparable in both arms. The 3-year progression-free survival for neoadjuvant versus control arm was 88.2% and 59.5% (hazard ratio = 0.49; 95% CI, 0.20 to 1.19; P = .12). The 3-year overall survival for neoadjuvant versus control arm was 94.1% and 67.7% (hazard ratio = 0.24; 95% CI, 0.078 to 0.73; P = .012). CONCLUSION: Neoadjuvant docetaxel-cisplatin followed by CRT was well tolerated with a manageable toxicity profile that allowed subsequent delivery of full-dose CRT. Preliminary results suggested a positive impact on survival. A phase III study to definitively test this neoadjuvant-concurrent strategy is warranted.

Quantitative analysis of the transrenal excretion of circulating EBV DNA in nasopharyngeal carcinoma patients.

PURPOSE: The existence of transrenal clearance of circulating cell-free DNA is controversial. In this study, we used NPC as a model to investigate if circulating EBV DNA can be excreted into urine and to quantify the contribution of renal excretion to the clearance of plasma EBV DNA. EXPERIMENTAL DESIGN: Quantitative analysis of urine EBV DNA was done for 74 NPC patients using real-time PCR with two different amplicon sizes. The urine concentration of EBV DNA was expressed as copies per millimole of creatinine (copies/mmol Cr) to minimize the effects of interindividual variations in hydration status. RESULTS: EBV DNA was detectable in the urine of 56% NPC patients using a 59-bp real-time PCR assay. The median urine EBV DNA concentrations measured by the 59- and 76-bp assays were 7,040 and 290 copies/mmol Cr, respectively. Patients with detectable urine EBV DNA had significantly higher plasma concentrations, with a positive correlation between the plasma and urine concentrations of EBV DNA. The fraction of plasma EBV DNA excreted into the urine was 0.0026% of that for creatinine. CONCLUSIONS: We have shown that circulating EBV DNA can be excreted transrenally into urine in NPC patient and the fraction of excretion is negatively associated with the size of the DNA molecules. Because there is a positive correlation between plasma and urine EBV DNA concentration, urine EBV DNA analysis may potentially be applicable as an ultra-noninvasive test for the monitoring and prognostication of NPC patients.

The prognostic significance of tumor vascular invasion and its association with plasma Epstein-Barr virus DNA, tumor volume and metabolic activity in locoregionally advanced nasopharyngeal carcinoma.

Parapharyngeal tumor invasion is a known predictor of distant recurrence in stage II-III nasopharyngeal carcinoma (NPC). This study evaluated the prognostic significance of parapharyngeal and cavernous sinus vascular invasion in stage III-IV NPC, and its association with plasma Epstein-Barr virus (pEBV) DNA, disease stage, tumor volume and metabolic activity. Eligible patients underwent magnetic resonance imaging (MRI), 18F-fluorodeoxyglucose (FDG)-positron-emission tomography (PET) and blood sampling for pEBV DNA before undergoing concurrent chemoradiotherapy. Relationship between treatment outcome and tumor vascular invasion was analyzed using Cox regression. Logistic regression was used to analyze the association between vascular invasion and other cofactors. Fifty seven patients with predominantly T3-T4 or N2-N3 stage disease were enrolled. Parapharyngeal invasion was present in 56% and cavernous sinus invasion in 19% of tumors. Multivariate analysis showed that tumor vascular invasion did not predict treatment outcome, while tumor FDG-uptake was the only significant factor that predicted survival and recurrence. Tumor vascular invasion was associated with T-stage, but not pEBV DNA or tumor volume. Parapharyngeal and cavernous sinus invasion were not significant predictors of distant recurrence following chemoradiotherapy in our cohort with locoregionally advanced NPC.

A phase II study of patients with metastatic or locoregionally recurrent nasopharyngeal carcinoma and evaluation of plasma Epstein-Barr virus DNA as a biomarker of efficacy.

BACKGROUND: The epidermal growth factor receptor (EGFR) is commonly overexpressed in nasopharyngeal carcinoma (NPC) and gefitinib inhibits NPC growth in vitro. METHOD: Patients who progressed after prior platinum-based chemotherapy for recurrent NPC were given gefitinib orally at 500 mg/day at a 28-day cycle. Plasma Epstein-Barr virus (pEBV) DNA levels were obtained at specific intervals. RESULTS: Sixteen patients enrolled and 15 were evaluable for response. The median age was 49 years (range 34-64 years), and most patients were males with metastatic NPC. No objective response was seen and three patients had stable disease (SD) for 2.8 to 8.5 months. Radiological progression of disease coincided with rising levels of pEBV DNA in most patients, while the level of a patient with the longest duration of SD fell to an undetectable level at study completion. The mean time to progression and overall survival was 2.7 (standard error, SE +/- 0.5 months) and 12 months (SE +/- 1.7 months), respectively. No unexpected drug-related toxicities were seen. The study was prematurely terminated because there was insufficient activity to warrant progression to the second stage of accrual. CONCLUSION: This study found limited activity of gefitinib in recurrent NPC. Further evaluation of pEBV DNA as a biomarker of response in clinical trials of target-based agents is warranted.

Cyclooxygenase-2 expression in advanced nasopharyngeal carcinoma--a prognostic evaluation and correlation with hypoxia inducible factor 1alpha and vascular endothelial growth factor.

Cycloxygenase-2 (COX-2), hypoxia inducible factor 1-alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) can be induced by the Epstein-Barr virus oncoprotein latent membrane protein-1 (LMP-1) in nasopharyngeal cancer (NPC) cell lines. This study examined the prognostic relevance of COX-2 and its relationship with HIF-1alpha and VEGF expression in NPC biopsies. Primary tumor biopsies were obtained from 78 participants of a randomized trial who received radiotherapy (RT) with or without concurrent chemotherapy for locoregionally advanced NPC. These were analyzed for COX-2 expression and then correlated with age, sex, disease stage, treatment arm, survival and disease recurrence, VEGF and HIF-1alpha expression in a regression model. 83% of tumors expressed COX-2, 47% co-expressed COX-2 and VEGF, 38% co-expressed COX-2 and HIF-1alpha. On univariate analysis, COX-2 expression did not correlate with survival and recurrence, but moderate to high COX-2 expression was associated with advanced nodal stage (p=0.03). Although univariate analysis showed that COX-2-HIF-1alpha co-expression was associated with worse progression-free survival (p=0.046), time to local (p=0.004) and regional recurrence (p=0.007), multivariate analysis failed to confirm any correlation between COX-2-HIF-1alpha or COX-2-VEGF co-expression and survival or disease recurrence. Contrary to previous report, this study failed to demonstrate any prognostic significance of COX-2 expression alone or co-expression with HIF-1alpha or VEGF in advanced NPC.

Radiological, pathological and DNA remission in recurrent metastatic nasopharyngeal carcinoma.

BACKGROUND: Circulating plasma Epstein Barr Virus DNA (EBV-DNA) is a sensitive and specific marker of nasopharyngeal carcinoma (NPC). The mainstay of treatment of metastatic NPC is systemic chemotherapy and resection for solitary metastasis. Despite high response rate to chemotherapy, complete remission is uncommonly seen. CASE PRESENTATION: We report a case of recurrent metastatic NPC in a 43-year-old man, who achieved complete remission three times with chemotherapy and surgery. Serial plasma EBV-DNA levels were measured during the course of disease. The patient had three episodes of recurrences of NPC manifested as distant metastasis. Both time, rise in the plasma EBV-DNA level preceded detection of recurrences by imaging. Following systemic chemotherapy, he achieved complete remission each time, of which was confirmed by 18-flourodeoxyglucose positron emission tomography and hepatectomy pathology. The plasma EBV-DNA level dropped to zero copy/ml at the time of each remission. CONCLUSION: This case highlights the high chemosensitivity of NPC by illustrating a rare occurrence of complete response of metastatic NPC to chemotherapy. This case also underscores the usefulness of EBV-DNA as a useful tool in monitoring NPC by its ability to detect early recurrence and excellent correlation with treatment response.

Relationship between pretreatment level of plasma Epstein-Barr virus DNA, tumor burden, and metabolic activity in advanced nasopharyngeal carcinoma.

PURPOSE: Plasma Epstein-Barr virus DNA (pEBV DNA) is an important prognostic marker in nasopharyngeal carcinoma (NPC). This study tested the hypotheses that pEBV DNA reflects tumor burden and metabolic activity by evaluating its relationship with tumor volume and 18F-fluorodeoxyglucose (18F-FDG) uptake in NPC. METHODS AND MATERIALS: Pre-treatment pEBV DNA analysis, 18F-FDG positron emission tomography-computed tomography scan (PET-CT) and magnetic resonance imaging (MRI) of the head and neck were performed in 57 patients. Net volume (cm3) of the primary tumor (T(vol)) and regional nodes (N(vol)) were quantified on MRI. 18F-FDG uptake was expressed as the maximum standardized uptake value (SUV(max)) at the primary tumor (T(suv)) and regional nodes (N(suv)). Lesions with SUV(max) > or = 2.5 were considered malignant. Relationship between SUV(max), natural logarithm (log) of pEBV DNA, and square root (sq) of MRI volumes was analyzed using the Wilcoxon test. A linear regression model was constructed to test for any interaction between variables and disease stage. RESULTS: Log-pEBV DNA showed significant correlation with sq-T(vol) (r = 0.393), sq-N(vol) (r = 0.452), total tumor volume (sq-Total(vol) = T(vol) + N(vol), r = 0.554), T(suv) (r = 0.276), N(suv) (r = 0.434), and total SUV(max) (Total(suv) = T(suv) + N(suv), r = 0.457). Likewise, sq-T(vol) was correlated to T(suv) (r = 0.426), and sq-N(vol) with N(suv) (r = 0.651). Regression analysis showed that only log-pEBV DNA was significantly associated with sq-Total(vol) (p < 0.001; parameter estimate = 8.844; 95% confidence interval = 3.986-13.703), whereas Sq-T(vol) was significantly associated with T(suv) (p = 0.002; parameter estimate = 3.923; 95% confidence interval = 1.498-6.348). CONCLUSION: This study supports the hypothesis that cell-free plasma EBV DNA is a marker of tumor burden in EBV-related NPC.

Chemotherapy in locally advanced nasopharyngeal carcinoma: an individual patient data meta-analysis of eight randomized trials and 1753 patients.

OBJECTIVES: To study the effect of adding chemotherapy to radiotherapy (RT) on overall survival and event-free survival for patients with nasopharyngeal carcinoma. METHODS AND MATERIALS: This meta-analysis used updated individual patient data from randomized trials comparing chemotherapy plus RT with RT alone in locally advanced nasopharyngeal carcinoma. The log-rank test, stratified by trial, was used for comparisons, and the hazard ratios of death and failure were calculated. RESULTS: Eight trials with 1753 patients were included. One trial with a 2 x 2 design was counted twice in the analysis. The analysis included 11 comparisons using the data from 1975 patients. The median follow-up was 6 years. The pooled hazard ratio of death was 0.82 (95% confidence interval, 0.71-0.94; p = 0.006), corresponding to an absolute survival benefit of 6% at 5 years from the addition of chemotherapy (from 56% to 62%). The pooled hazard ratio of tumor failure or death was 0.76 (95% confidence interval, 0.67-0.86; p < 0.0001), corresponding to an absolute event-free survival benefit of 10% at 5 years from the addition of chemotherapy (from 42% to 52%). A significant interaction was observed between the timing of chemotherapy and overall survival (p = 0.005), explaining the heterogeneity observed in the treatment effect (p = 0.03), with the highest benefit resulting from concomitant chemotherapy. CONCLUSION: Chemotherapy led to a small, but significant, benefit for overall survival and event-free survival. This benefit was essentially observed when chemotherapy was administered concomitantly with RT.

Lung metastasis alone in nasopharyngeal carcinoma: a relatively favorable prognostic group. A study by the Hong Kong Nasopharyngeal Carcinoma Study Group.

BACKGROUND: The current study was conducted to examine the pattern and the predictive factors of distant metastases (DM) in patients with nasopharyngeal carcinoma (NPC) after primary radiotherapy treatment. METHODS: Data from all five regional cancer centers in Hong Kong were collected retrospectively and pooled for the current study, which was coordinated by the Hong Kong Nasopharyngeal Carcinoma Study Group. The sample was comprised of all 2915 patients with NPC without DM at the time of presentation who were treated with radiotherapy in 1 of the 5 cancer centers during the period between January 1996 and December 2000. RESULTS: DM was found to be the leading cause of NPC failure, with a 5-year actuarial rate of 14.9% in this patient cohort. Despite the poor overall survival (OS) of these patients, those with lung metastasis alone represented a distinctive group associated with a significantly better OS. International Union Against Cancer (UICC) N classification, UICC T classification, advanced age, and male gender were found to be significant and independent determinants for DM. CONCLUSIONS: Long-term survival is possible in patients with distant metastatic NPC confined to the lung. An aggressive approach to treatment for this group of patients should be considered.

A prospective study of pre-treatment cell kinetics and clinical outcome in nasopharyngeal carcinoma.

BACKGROUND AND PURPOSE: To study pre-treatment cell kinetics and their clinical correlations in nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: Ninety newly diagnosed NPC patients were studied using in vivo Bromodeoxyuridine (BrdU) labeling and flow cytometric analysis. Immunohistochemical staining for BrdU and Ki 67 was also performed. RESULTS: The median S-phase duration (Ts) was 6.2 h (range 3.5-18.7 h), median flow cytometric labeling index (FCM-LI) was 7.4% (1.3-37.6%), and median potential doubling time (Tpot) was 3.6 days (0.5-19.9 days). The median histologic labeling index (H-LI) was 12.4% (1.2-43.3%), and median histologic Tpot (H-Tpot) was 2.1 days (0.5-33.3 days). FCM-LI and H-LI were both positively correlated with Ki67 whereas Tpot and H-Tpot were both negatively correlated with Ki67 and N-stage. In univariate analysis, Tpot and H-Tpot showed a trend for progression free survival. Tpot was significantly associated with local relapse free survival, but lost its significance in multivariate analysis. N-stage was the only significant prognostic factor for all radiotherapy outcomes in both univariate and multivariate analyses. CONCLUSIONS: Tpot was the only pre-treatment cell kinetic parameter for which some evidence was found for an association with survival in NPC patients. Future studies should aim to combine cell kinetic parameters together with other biological markers and clinical parameters to provide more useful prognostic information to guide individual patient's therapy.