Nasopharyngeal carcinoma: treatments and outcomes in the 20th century

Nutlin-3, A p53-Mdm2 Antagonist for Nasopharyngeal Carcinoma Treatment

Nasopharyngeal carcinoma (NPC) is a form of head and neck cancer of multifactorial etiolo-gies that is highly prevalent among men in the population of Southern China and Southeast Asia. NPC has claimed many thousands of lives worldwide; but the low awareness of NPC remains a hindrance in early diagnosis and prevention of the disease. NPC is highly responsive to radiotherapy and chemothera-py, but radiocurable NPC is still dependent on concurrent treatment of megavoltage radiotherapy with chemotherapy. Despite a significant reduction in loco-regional and distant metastases, radiotherapy alone has failed to provide a significant improvement in the overall survival rate of NPC, compared to chemo-therapy. In addition, chemo-resistance persists as the major challenge in the management of metastatic NPC although the survival rate of advanced metastatic NPC has significantly improved with the admin-istration of chemotherapy adjunctive to radiotherapy. In this regard, targeted molecular therapy could be explored for the discovery of alternative NPC therapies. Nutlin-3, a small molecule inhibitor that specifi-cally targets p53-Mdm2 interaction offers new therapeutic opportunities by enhancing cancer cell growth arrest and apoptosis through the restoration of the p53-mediated tumor suppression pathway while pro-ducing minimal cytotoxicity and side effects. This review discusses the potential use of Nutlin-3 as a p53-activating drug and the future directions of its clinical research for NPC treatment.

CT-guided 125I brachytherapy for locally recurrent nasopharyngeal carcinoma

Purpose: The study evaluated the feasibility, clinical effectiveness, and quality of life of computed tomography (CT)-guided 125I brachytherapy for locally recurrent nasopharyngeal carcinoma (NPC). Methods: We recruited 81 patients diagnosed with locally recurrent NPC after previous radiotherapy with or without chemotherapy. Thirty-nine patients received 125I brachytherapy (group A) and 42 received re-irradiation (IMRT, group B). The evaluated outcomes were local control, complications, and quality of life. Cox proportional hazards regression analysis was used to compare local tumor progression-free survival (LTPFS) and overall survival (OS) in the two treatment groups. Results: The median follow-up was 30 months (range, 5-68 months), median LTPFS was 21 in group A and 17 months in group B. The 1-, 2-, and 3-year OS in group A were 84.6%, 51.3%, 30.7%, and 85.7%, 50.0%, and 32.6% in group B. In group A, 10/39 patients (25.6%) experienced at least one ≥grade III complication; no grade V complications occurred. In group B, 28/42 (66.7%) experienced at least one ≥grade III complication and 6/42 (14.3%) died of severe grade V complications. No significant between-group difference existed in the Quality of Life score on the EORTC QLQ-H&N35 questionnaire before treatment. In group A, quality of life was significantly improved after treatment; but did not improve, or even deteriorated in group B. Conclusions: 125I brachytherapy was a feasible, safe, and effective treatment for locally recurrent NPC. 125I brachytherapy significantly reduced complications caused by re-irradiation and improved patients' quality of life.

Designing an effective vaccine to prevent Epstein-Barr virus-associated diseases: challenges and opportunities

INTRODUCTION

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus associated with a number of clinical manifestations. Primary EBV infection in young adolescents often manifests as acute infectious mononucleosis and latent infection is associated with multiple lymphoid and epithelial cancers and autoimmune disorders, particularly multiple sclerosis. Areas covered: Over the last decade, our understanding of pathogenesis and immune regulation of EBV-associated diseases has provided an important platform for the development of novel vaccine formulations. In this review, we discuss developmental strategies for prophylactic and therapeutic EBV vaccines which have been assessed in preclinical and clinical settings. Expert commentary: Major roadblocks in EBV vaccine development include no precise understanding of the clinical correlates of protection, uncertainty about adjuvant selection and the unavailability of appropriate animal models. Recent development of new EBV vaccine formulations provides exciting opportunities for the formal clinical assessment of novel formulations.

Nasopharyngeal cancer-specific therapy based on fusion peptide-functionalized lipid nanoparticles

Current treatment of advanced-stage nasopharyngeal carcinoma (NPC) is not satisfactory. Targeted therapies offer hope for extending survival. Here, we developed simple, robust, and NPC-specific therapeutic lipid nanoparticles based on a fusion peptide, α-NTP, made up of an amphipathic α-helical peptide (α-peptide) linked to an NPC-specific therapeutic peptide (NTP). We found that α-NTP not only retained the sub-30 nm nanostructure-controlling ability of the α-peptide but also displayed the enhanced NPC-targeting ability of the NTP, in which the α-peptide accelerated the uptake of the NTP by NPC cells, with a 4.8-fold increase. Following uptake, α-NTP-based lipid nanoparticles (α-NTP-LNs) exerted coordinated cytotoxicity by inducing cell death via apoptosis and autophagy. In vivo and ex vivo optical imaging data showed that systemically administered α-NTP-LNs efficiently accumulated in the NPC xenograft tumor and displayed high contrast between tumor and normal tissues, which was further confirmed by flow cytometry that there had been a 13-fold uptake difference between tumor cells and hepatocytes. More importantly, the therapeutic efficacy of α-NTP-LNs was specific to NPC xenograft formed with 5-8F cells but not to fibrosarcoma xenograft formed with HT1080 cells in vivo. The growth of 5-8F tumors was significantly inhibited by α-NTP-LNs, with more than 85% inhibition relative to control groups (e.g., α-NTP and PBS treatment). In a lung metastasis model of NPC, survival was significantly improved by α-NTP-LN treatment. In a word, these excellent properties of α-NTP-LNs worked in sync and synergistically, maximizing the therapeutic efficacy of α-NTP-LNs against NPC and its metastasis.

Association between the p73 G4C14-to-A4T14 polymorphism and risk of nasopharyngeal carcinoma: a case-control and family-based study

p73, a structural and functional homolog of p53, plays an important role in modulating cell cycle control and apoptosis. We examined whether the p73 G4C14-to-A4T14 polymorphism was related to the risk of nasopharyngeal carcinoma (NPC) among Chinese populations. The G4C14-to-A4T14 polymorphism was genotyped in 593 NPC cases and 480 controls, and in 102 NPC trios. Logistic regression analysis and transmission/disequilibrium tests (TDT) were performed to evaluate whether there was an association between the polymorphism and NPC, respectively. Functional analyses were conducted to verify the biological relevance of the polymorphism. We observed that compared with the GC/GC genotype, the genotypes containing AT allele (GC/AT + AT/AT genotypes) were associated with significantly increased susceptibility to NPC [odds ratio (OR) = 1.51; 95% confidence interval (CI) = 1.16-1.95; P = 0.002]. Furthermore, compared with the GC/GC genotype, the GC/AT + AT/AT genotypes were significantly associated with the advanced lymph node metastasis (OR = 1.47; 95% CI = 1.02-2.11; P = 0.041). A significantly greater than expected transmission of the AT allele from heterozygous parents to offspring was also observed (P = 0.049) using the TDT. By using the TdT-mediated dUPT-biotin nick end labeling assay, we observed lower apoptosis in NPC tissues from the AT allele carriers compared with that from non-carriers. Furthermore, the relative TAp73 RNA levels of the AT allele were lower than those of the GC allele in heterozygous cells. Our findings suggest that the p73 G4C14-to-A4T14 polymorphism may play a role in mediating the susceptibility to NPC in Chinese populations.

Recurrent nasopharyngeal carcinoma: a clinical dilemma and challenge

Recurrent nasopharyngeal carcinoma, which represents a small proportion of head-and-neck cancers, has a unique set of patho-clinical characteristics. The management of recurrent nasopharyngeal carcinoma remains a challenging clinical problem. Traditional treatments offer limited local control and survival benefits; more seriously, they frequently induce severe late complications. Recently, novel treatment techniques and strategies-including precision radiotherapy, endoscopic surgery or transoral robotic resection, third-generation chemotherapy regimens, and targeted therapies and immunotherapy-have provided new hope for patients with recurrent nasopharyngeal carcinoma. Some of these patients can potentially be cured with modern treatments. However, a lack of adequate evidence makes it difficult for clinicians to apply these powerful techniques and strategies. Individualized management guidelines, full evaluation of quality of life in these patients, and a further understanding of the mechanisms underlying recurrence are future directions for research into recurrent nasopharyngeal carcinoma.

Human papillomavirus and Epstein-Barr virus in nasopharyngeal carcinoma in a low-incidence population

BACKGROUND

The significance of human papillomavirus (HPV) in nasopharyngeal carcinomas (NPCs) in a low-incidence population remains unknown.

METHODS

Samples from 90 patients with NPC (years, 1957-2012) were analyzed for Epstein-Barr virus (EBV). Clinical data, EBV, HPV, and p16 status were correlated with overall survival (OS; 63 cases; years, 1981-2012).

RESULTS

Of 9 HPV-positive cases, 3 extended from extra-nasopharyngeal sites. Nasopharyngeal origin was confirmed in 6 cases. HPV-positive NPC had OS similar to EBV-positive NPC (85 vs 141 months; p > .05). The OS of patients with EBV/HPV-negative NPC was worse (34 months; p = .004). Nonkeratinizing histology was associated with better outcome than keratinizing (115 vs 25 months; p = .001). Over the last several decades, the proportion of keratinizing NPC decreased from 34.5% to 14.3% (p = .026).

CONCLUSION

The etiologic role of HPV in NPC is confirmed. The favorable prognostic significance of HPV positivity is similar to that of EBV positivity.

Trends in the survival of patients with nasopharyngeal carcinoma between 1976 and 2005 in Sihui, China: a population-based study

Both the incidence and mortality of nasopharyngeal carcinoma (NPC) have decreased in Hong Kong and Taiwan but not in mainland China. The goal of this study was to analyze trends in NPC patient survival between 1976 and 2005 in Sihui, an area of mainland China with a population at high risk for NPC. A total of 1,761 patients diagnosed with NPC between 1976 and 2005 according to the records of Sihui Cancer Registry were followed to the end of 2006. We determined their observed and relative survival rates and used Cox proportional hazards regression analysis to predict prognosis. Our results showed that the 5-year and 10-year observed survival rates of NPC patients in Sihui were 50.5% and 36.9%, respectively, and the median survival time was 5.1 years. The 5-year observed survival rate of NPC patients diagnosed after 2000 was 69.8%, significantly higher than that of patients diagnosed between 1976 and 1985 (42.5%; P < 0.001, relative risk = 0.28). Similarly, the 5-year relative survival rate was 84.8% between 2000 and 2005 but 51.8% between 1976 and 1985. Besides date of diagnosis, other prognostic factors included patient sex and age and NPC clinical stage and histologic type. The relative risks of death from NPC were 0.76 [95% confidence interval (CI): 0.65–0.90] for female comparing to male and 1.28 (95% CI: 1.00–1.64) for WHO type I comparing to WHO types II and III. For the eldest age group and the latest clinical stage group, the relative risks were 2.22 (95% CI: 1.73–2.84) and 3.41 (95% CI: 2.34–4.49), respectively. Our results indicate that the survival of NPC patients in Sihui has significantly increased in recent years and this increase is not influenced by patient's sex, age, histologic type, and clinical stage. A reduction in mortality rate is expected in coming years.

Late toxicities after conventional radiation therapy alone for nasopharyngeal carcinoma

BACKGROUND AND PURPOSE

We sought to evaluate the nature and frequency of late toxicities in a cohort of nasopharyngeal cancer (NPC) patients treated with conventional radiotherapy alone.

METHODS AND MATERIALS

Seven-hundred and ninety-six consecutive NPC patients treated using conventional radiotherapy at a single center from 1992 to 1995 were retrospectively analyzed. Patients with histology proven, completely staged, Stage I-IVB World Health Organization Type I-III NPC and completed radical radiotherapy were included. Patients with incomplete staging investigations, distant metastases at diagnosis, previous treatment, and incomplete radiotherapy were excluded. Radiotherapy-related complications were categorized using the RTOG Late Radiation Morbidity Scoring Criteria.

RESULTS

Median follow-up was 7.2 years. The 5-year overall survival and disease free survival were 69% and 56%, respectively, and the corresponding 10-year rates were 52% and 44%. Among 771 patients with at least 3 months of follow-up post treatment, 565 (73%) developed RT-related complications. Diagnosed neurological complications were cranial nerve palsies (n=70; 9%), temporal lobe necrosis (n=37; 5%), Lhermitte's syndrome (n=7; 1%), and brachial plexopathy (n=2; 0.3%). Non-neurological complications included xerostomia (n=353; 46%), neck fibrosis (n=169; 22%), hypo-pituitarism (n=48; 6%), hearing loss (n=120; 16%), dysphagia (n=116; 15%), otorrhea (n=101; 13%), tinnitus (n=94; 12%), permanent tube feeding (n=61; 8%), trismus (n=45; 6%), second malignancies within treatment field (n=17; 2%), and osteo-radionecrosis (n=13; 2%).

CONCLUSIONS

While radiotherapy is curative in NPC, many patients suffer significant late treatment morbidities with conventional radiotherapy techniques.

Reactive oxygen species-mediated mitochondrial dysfunction is involved in apoptosis in human nasopharyngeal carcinoma CNE cells induced by Selaginella doederleinii extract

ETHNOPHARMACOLOGICAL RELEVANCE

A traditional Chinese medicine Selaginella doederleinii Hieron has been combined with radiotherapy for the treatment of human nasopharyngeal carcinoma in clinic in China. However, the detailed mechanism of anti-tumor effect of Selaginella doederleinii remains elusive.

AIM OF THE STUDY

This study was designed to investigate the anti-tumor effect of ethanol extract of Selaginella doederleinii (SDE) on human nasopharyngeal carcinoma and its possible mechanisms.

MATERIALS AND METHODS

Viability, apoptosis and protein expression of tumor cells were analyzed by MTT, Annexin V staining and Western blot, respectively. Formation of intracellular reactive oxygen species was determined using dichlorofluorescin fluorescence. The in vivo anti-tumor effect was evaluated by measuring tumor volume changes and TUNEL staining in nude mice.

RESULTS

SDE significantly inhibited the growth and induced apoptosis in human nasopharyngeal carcinoma CNE cells. In addition, SDE triggered the mitochondrial/caspase apoptotic pathway indicated by enhanced Bax-to-Bcl-2 ratio, loss of mitochondrial membrane potential, cytochrome c release, and caspase cascade. Moreover, SDE provoked the generation of reactive oxygen species in CNE cells, while the antioxidant N-acetyl cysteine almost completely blocked SDE-induced disruption of mitochondrial membrane potential, caspases activation and apoptosis. Furthermore, a transplantable nude mice model was utilized to estimate the effectiveness of SDE in vivo. The treated mice displayed decreased tumor size, which was associated with enhanced apoptotic cell death.

CONCLUSIONS

These results, offering solid evidence of the induction of mitochondria-related apoptosis in tumor cells, provide the molecular theoretical basis of clinical application of Selaginella doederleinii for the treatment of human nasopharyngeal carcinoma.

A phase II study evaluating the safety and efficacy of an adenovirus-ΔLMP1-LMP2 transduced dendritic cell vaccine in patients with advanced metastatic nasopharyngeal carcinoma

BACKGROUND

Individuals with metastatic Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) continue to have poor outcomes. To evaluate the ability of a dendritic cell (DC) vaccine to target subdominant EBV antigens LMP1 and LMP2 expressed by NPC cells, we vaccinated patients using autologous DCs transduced with an adenovirus encoding a truncated LMP1 (ΔLMP1) and full-length LMP2 (Ad-ΔLMP1-LMP2).

MATERIALS AND METHODS

Sixteen subjects with metastatic NPC received Ad-ΔLMP1-LMP2 DC vaccines i.d. biweekly for up to five doses. Toxicity, immune responses and clinical responses were determined.

RESULTS

Most patients had extensive disease, with a median of three visceral sites of involvement (range 1-7). No significant toxicity was observed. Ad-ΔLMP1-LMP2 DCs induced delayed type hypersensitivity responses in 9 out of 12 patients, but although these DCs activated LMP1/2-specific T cells in vitro, no such increase in the frequency of peripheral LMP1/2-specific T cells was detected. Three patients had clinical responses including one with partial response (for 7½ months) and two with stable disease (for 6½ and 7½ months).

CONCLUSIONS

Ad-ΔLMP1-LMP2 transduced DCs can be successfully generated and safely administered to patients with advanced NPC. Since efficacy was limited, future studies should focus on DC vaccines with greater potency administered to subjects with less tumor burden.

Adoptive transfer of EBV-specific T cells results in sustained clinical responses in patients with locoregional nasopharyngeal carcinoma

Patients with recurrent or refractory Epstein Barr Virus (EBV)-positive nasopharyngeal carcinoma (NPC) continue to have poor outcomes. Our earlier Phase I dose escalation clinical study of 10 NPC patients showed that infusion of EBV-specific cytotoxic T cells (EBV-CTLs) was safe and had antitumor activity. To better define the overall response rate and discover whether disease status, EBV-antigen specificity, and/or in vivo expansion of infused EBV-CTLs predicted outcome, we treated 13 additional NPC patients with EBV-CTLs in a fixed-dose, Phase II component of the study. We assessed toxicity, efficacy, specificity, and expansion of infused CTLs for all 23 recurrent/refractory NPC patients treated on this Phase I/II clinical study. At the time of CTL infusion, 8 relapsed NPC patients were in remission and 15 had active disease. No significant toxicity was observed. Of the relapsed patients treated in their second or subsequent remission, 62% (5/8) remain disease free (at 17 to 75 mo), whereas 48.7% (7/15) of those with active disease had a CR/CRu (33.3%) or PR (15.4%). In contrast to locoregional disease, metastatic disease was associated with an increased risk of disease progression (HR: 3.91, P=0.015) and decreased overall survival (HR: 5.55, P=0.022). Neither the specificity of the infused CTLs for particular EBV antigens nor their measurable in vivo expansion discernibly influenced outcome. In conclusion, treatment of patients with relapsed/refractory EBV-positive NPC with EBV-CTLs is safe and can be associated with significant, long-term clinical benefit, particularly for patients with locoregional disease.

Recurrent nasopharyngeal carcinoma: current management approaches

OBJECTIVES

Providing the primary recurrence is localized, salvage treatment is possible for nasopharyngeal carcinoma (NPC). This is a review of the experience of retreatment of this malignancy highlighting the roles of surgery and repeat radiotherapy.

METHODS

The Tumor Registry of the Prince of Wales Cancer Centre was audited for patients with an initial diagnosis of squamous/nonsquamous cell NPC who had primary treatment with radiotherapy, and now presented for retreatment. Features relating to patient, disease and treatment factors were evaluated. The primary end point was subsequent local control, and secondary endpoints were overall and cancer-specific survival.

RESULTS

Over a 30-year period 39 patients were eligible, with 25 receiving both primary and retreatment at Prince of Wales Hospital. There were 25 males and 14 females with a median age of 50 years. Thirty-six patients had radiotherapy, 4 had stereotactic radiosurgery, 5 had brachytherapy, and the remainder had external treatment. Surgery was performed in 10 patients, of whom 3 had this as the only retreatment modality. Radiotherapy doses for retreatment ranged from 15 Gy (stereotactic radiosurgery) to 71.28 Gy (mean fractionated dose). Local control was achieved in 16 patients giving an overall rate of 41.0%, and the 5-year overall survival rate was 33.3%. Treatment modality was a significant prognostic factor for local control (P < 0.001) and cancer-specific survival (P < 0.05).

CONCLUSION

The presence of local recurrence after definitive treatment of NPC may still be salvageable. The best outcomes with reirradiation occur in the context of limited volume recurrence and a disease-free interval greater than 18 months.

Results of excision of cerebral radionecrosis: experience in patients treated with radiation therapy for nasopharyngeal carcinoma

OBJECT

In theory, the purpose of the treatment of cerebral radionecrosis (CRN), a nonneoplastic condition, is to minimize loss of brain function by preventing the progression and reversing some of the processes of CRN. In a practical sense, factors for achieving this purpose may include the following: removal of a CRN lesion that is causing mass effect, control of brain edema, prevention of recurrence of CRN lesions, minimization of adverse effects from treatments, and achievement of reasonably long and good-quality survivals. Based on these practical issues, the authors performed a retrospective study to evaluate the results of excision for the treatment of CRN.

METHODS

The authors retrospectively reviewed the results of excision of CRN lesions in a group of patients with temporal lobe CRN due to radiotherapy for nasopharyngeal carcinoma. Patients who had undergone surgery at the authors' institution between January 1998 and November 2008 were analyzed. Surgical results were evaluated by assessing postoperative resolution of brain edema, recurrence of temporal lobe CRN, surgery-related complications, and postoperative functional status and survival.

RESULTS

Twenty-four patients were included (age range 39-69 years; in 23 patients nasopharyngeal carcinoma was in remission). All patients underwent craniotomy for excision of the contrast-enhancing region. The indications for operation were temporal lobe CRN lesions with a mass-occupying effect beyond the temporal lobe. There were 32 craniotomies in all (mean postoperative follow-up 40 months). It was found that brain edema resolved rapidly postoperatively. The recurrence and reoperation rates were 6.3 and 3.1%, respectively. There were no surgery-related deaths. The median survival was 72 months, and 67% of the patients had a Karnofsky Performance Scale score of > or = 70% at the time of their last follow-up.

CONCLUSIONS

In a specific group of patients with CRN of the temporal lobe in whom the CRN lesions were causing a mass-occupying effect beyond the temporal lobe, excision of the contrast-enhancing region was safe and could achieve prompt resolution of brain edema and a low incidence of recurrence of CRN.

Enhancing the in vivo expansion of adoptively transferred EBV-specific CTL with lymphodepleting CD45 monoclonal antibodies in NPC patients

Treatment of Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) with EBV-specific cytotoxic T cells (EBV-specific CTL) has been promising, producing clinical responses. However, infused EBV-specific CTL did not expand in vivo, likely limiting their antitumor activity. Lymphodepleting patients with chemotherapy before T-cell transfer enhances in vivo T-cell expansion, but results in nonspecific destruction of the resident immune system and can have significant toxicity. To evaluate if monoclonal antibodies (mAbs) can produce a more selective lymphodepletion, we conducted a clinical study in which NPC patients received a pair of lymphodepleting mAbs targeted to the CD45 antigen (CD45 mAbs) before EBV-specific CTL infusion. Eight patients with recurrent NPC received CD45 mAbs followed by escalating doses of autologous EBV-specific CTL. Infusion of CD45 mAbs resulted in transient lymphopenia in all patients and an increase in interleukin-15 (IL-15) levels in 6 out 8 patients. All patients had an increase in their peripheral blood frequency of EBV-specific T cells after CTL infusion. Three patients with a persistent increase had clinical benefits including 1 complete response (> 24 months) and 2 with stable disease (for 12 and 15 months). Lymphodepleting mAbs prior CTL transfer may represent an alternative to chemotherapy to enhance expansion of infused CTL. This study is registered at (http://www.clinialtrials.gov) as NCT00608257.

Spontaneous T cell responses to Epstein-Barr virus-encoded BARF1 protein and derived peptides in patients with nasopharyngeal carcinoma: bases for improved immunotherapy

Immunotherapy approaches targeting Epstein-Barr virus (EBV)-encoded antigens induce objective clinical responses only in a fraction of patients with undifferentiated nasopharyngeal carcinoma (UNPC). In the present study, we have characterized the immunogenicity of the EBV-encoded BARF1 oncogene with the aim to assess whether this protein could constitute a new target antigen for immunotherapy in this setting. Spontaneous CD4+ and CD8+ T cell responses specific for the recombinant p29 BARF1 protein were detected by IFNgamma-ELISPOT in both EBV-seropositive donors and UNPC patients, but not in EBV-seronegative individuals. Using immunoinformatic prediction tools, we have selected 5 different candidate BARF1 T cell epitopes presented by HLA-A*0201. Although only one of these peptides was able to bind HLA-A2 with low affinity in the T2 stabilization assay, all 5 BARF1 nonamers readily elicited specific CD8+ T cell responses in EBV-seropositive HLA-A*0201+ donors and UNPC patients. Notably, the magnitude of CD8+ T cell responses to the whole BARF1 protein and derived A*0201 peptides was significantly higher in UNPC patients than in healthy donors. Moreover, cytotoxic T lymphocytes specific for the p2-10, p23-31, or p49-57 BARF1 peptides were easily obtained from HLA-A*0201+ donors. These cultures were not only able to lyse autologous targets loaded with the antigenic peptide, but also recognized tumor cells endogenously expressing BARF1 in an antigen-specific and HLA-A2-restricted manner. These findings, indicate that BARF1 is a particularly attractive antigen with immunogenic properties in most UNPC patients and provide valuable information to develop new strategies to improve the efficacy of EBV-targeting immunotherapy of UNPC patients.

Functional inactivation of EBV-specific T-lymphocytes in nasopharyngeal carcinoma: implications for tumor immunotherapy

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV) associated malignancy with high prevalence in Southern Chinese. In order to assess whether defects of EBV-specific immunity may contribute to the tumor, the phenotype and function of circulating T-cells and tumor infiltrating lymphocytes (TILs) were investigated in untreated NPC patients. Circulating naïve CD3⁺CD45RA⁺ and CD4⁺CD25⁻ cells were decreased, while activated CD4⁺CD25⁺ T-cells and CD3⁻CD16⁺ NK-cells were increased in patients compared to healthy donors. The frequency of T-cells recognizing seven HLA-A2 restricted epitopes in LMP1 and LMP2 was lower in the patients and remained low after stimulation with autologous EBV-carrying cells. TILs expanded in low doses of IL-2 exhibited an increase of CD3⁺CD4⁺, CD3⁺CD45RO⁺ and CD4⁺CD25⁺ cells and 2 to 5 fold higher frequency of LMP1 and LMP2 tetramer positive cells compared to peripheral blood. EBV-specific cytotoxicity could be reactivated from the blood of most patients, whereas the TILs lacked cytotoxic activity and failed to produce IFNγ upon specific stimulation. Thus, EBV-specific rejection responses appear to be functionally inactivated at the tumor site in NPC.

Comprehensive epitope mapping of the Epstein-Barr virus latent membrane protein-2 in normal, non tumor-bearing individuals

Latent membrane protein (LMP)-2 is one of the Epstein-Barr virus (EBV)-encoded proteins consistently expressed by nasopharyngeal carcinoma (NPC). EBV-transformed lymphoblastoid cell lines (LCL) have been used in patients with NPC to induce LMP-2-recognizing T cell lines which have been in turn utilized for protein-wide mapping of T cell epitopes. However, comprehensive mapping of naturally recognized LMP-2 epitopes in non tumor-bearing individuals has not been reported. Here, we applied a low sensitivity epitope-defining technique for the identification of LMP-2 CTL responses detectable ex vivo in EBV-experienced individuals. This screening tool has been previously validated by analyzing memory CTL responses to Flu, cytomegalovirus (CMV), and the melanoma associated antigen gp100/Mel17. Peripheral blood monocytes (PBMC) from ten Caucasian and ten Chinese individuals were stimulated ex vivo with pools of nonamer (9-mer) peptides overlapping in a stepwise fashion each single amino acid of the LMP-2 sequence. No obvious differences were observed between the immune response of the two ethnic groups save for those related to the divergence in the ethnic prevalence of HLA haplotypes. Several novel and known LMP-2 epitopes were identified. Reactivity toward at least one LMP-2 epitope was detected in 18 of the 20 donors but no prevalent human leukocyte antigen (HLA)/epitope combination was observed confirming that LMP-2 reactivity in the context of common HLA alleles is more pleiotropic than that of FLU and CMV. We believe that the usefulness of these epitopes occurring naturally in non-cancer bearing patients as reagents for the immunization of patients with early or advanced stage NPC deserves further evaluation.

Cranial nerve involvement in nasopharyngeal carcinoma: response to radiotherapy and its clinical impact

OBJECTIVES

To evaluate the cranial nerve (CN) palsy associated with nasopharyngeal carcinoma (NPC), we studied factors that influenced the neurologic outcome of radiotherapy (RT), and the patterns and time course of neurologic recovery of CN palsy.

METHODS

Between July 1987 and July 1989, 93 patients who presented with CN palsy at the time of diagnosis of NPC were studied. All patients underwent external-beam RT with either cobalt-60 or 6-MV photon beams to a dose of 69 to 84 Gy at 2 Gy per fraction. The time course and pattern of neurologic recovery (complete, partial, or none) from CN palsy were evaluated. Age, sex, stage, histology, incidence and distribution of types of CNs involved, duration of CN palsy, and time course of tumor response during RT were correlated with the patterns and the time course of neurologic CN recovery by univariate and multivariate analyses.

RESULTS

The cases of CN palsy most commonly involved CN V (38%), CN VI (26%), and CN XII (11%), which accounted for the majority of the cases (75%). The time course of CN recovery was variable and protracted. Most patients showed significant improvement upon completion of RT (51%, 19%, and 30% complete, partial, and no recovery, respectively) and further improvement 6 months after RT (58%, 17%, and 25%, respectively). Cranial nerves V, VI, and XII accounted for 75% of cases with no recovery. Recovery was best for CNs II, IX, and XI and the sympathetic nerve (100%, 87%, 100%, and 100%, respectively) and worst for CNs IV, VII, and XII (67%, 60%, and 40%, respectively, with no recovery). Neurologic CN recovery correlated significantly with the pretherapy duration (<3 months versus > or =3 months) of CN palsy (88% versus 62%; p = .002, multivariate analysis), the time course of clinical tumor regression, and neurologic symptom improvement during RT. Age, sex, T stage, N stage, histology, anterior versus posterior CN palsies, and base of skull involvement were not significant.

CONCLUSIONS

According to our limited data, most patients with CN palsy respond well to RT. That the time course of neurologic recovery is variable and can be protracted indicates a need for continuous and close neurologic surveillance. The poorer neurologic outcome associated with a longer duration of CN symptoms may be related to a more severe longterm CN compression that results in irreversible damage. Timely diagnosis of NPC and fast institution of therapy are therefore critical to improving the neurologic outcome.

Dose Escalation of Three-dimensional Conformal Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma: A Prospective Randomised Study

AIMS

To investigate prospectively the feasibility and efficacy of dose escalation using three-dimensional conformal radiotherapy (3D-CRT) boost technique for locally recurrent nasopharyngeal carcinoma (NPC) in a randomised study.

MATERIALS AND METHODS

Thirty-six patients with locally recurrent NPC (>6 months interval from previous radical radiotherapy, no cervical lymph-node involvement and no distant metastasis) were enrolled. Treatment included conventional external-beam radiotherapy to 54 Gy, followed by a 3D-CRT boost to the gross tumour region. Patients were randomised to three boost dose levels: 16 Gy, 20 Gy and 24 Gy for groups I, II and III, respectively, with 12 patients in each group. All boost doses were delivered in 4-Gy fractions and 3 fractions per week. Median follow-up was 27 months (range 14-44 months).

RESULTS

Three-year, local-recurrence-free survival rate was significantly higher (72%) for the high-dose group III than for groups I and II (37% and 28%, respectively, P = 0.047). No significant difference was found in the 3-year overall survival rate among the three groups (72%, 59% and 82% for groups I, II and III, respectively). Three-year distant metastases rates were 17%, 0% and 18%, respectively. Skull-base invasion (P = 0.017) and pathology (P = 0.0006) correlated with overall survival. Treatment was well tolerated and no significant difference was observed among the three groups in acute and late toxicities (grade III toxicity is minimal: 17%, 17%, 0% of oral mucositis and 25%, 17%, 17% of nasopharyngeal mucositis in groups I, II, III, respectively, and 8% leukocytopenia only in group II; no grade IV toxicity occurred in any of the groups except for a fatal bleeding in group III).

CONCLUSIONS

Re-irradiation with high-dose 3D-CRT boost technique results in high local control rate and acceptable toxicity in patients with recurrent NPC. Dose escalation to the boost volume to 78 Gy (54 Gy + 24 Gy boost) results in improved recurrence-free survival compared with lower doses.

Staging of nasopharyngeal carcinoma investigated by magnetic resonance imaging

BACKGROUND AND PURPOSE

To investigate the American Joint Commission on Cancer (AJCC) sixth edition staging system of nasopharyngeal carcinoma (NPC) by Magnetic Resonance Imaging (MRI).

PATIENTS AND METHODS

One hundred and fifty-nine non-disseminated biopsy-proven NPC patients were studied with MRI before treatment. Retrieval of MRI information enabled us to restage all patients accurately according to the sixth edition of the AJCC staging system. Splitting the respective T and N stages by the significant defining factors identified, the cancer death hazard ratios were modeled by the Cox model in SPSS 10.0 for windows (SPSS Inc, Chicago, IL).

RESULTS

Single site of skull base abnormality (HR = 3.91, 95% CI: 0.74-20.56) has a superior result to others involved in T3 (HR = 5.83, 95% CI: 1.24-27.29). Involvement of either anterior or posterior cranial nerves solely (HR = 6.02, 95% CI: 1.55-35.60) was not found to be as a poor prognostic indicator as others involved in T4 (HR = 7.81, 95% CI: 1.81-33.63). Less than or equal to 3 cm of N1 (HR = 4.01, 95% CI: 0.48-33.83) and N2 (HR = 4.72, 95% CI: 0.62-35.78) have a better result than >3 cm of N1 (HR = 8.09, 95% CI: 0.95-68.97) and N2 (HR = 10.58, 95% CI: 1.32-84.62), respectively.

CONCLUSIONS

Perhaps, it is better to down-stage single site of skull base abnormality from T3 to T2, and involvement of either anterior or posterior cranial nerves solely from T4 to T3, meanwhile, < or =3 cm of N2 down-stage to N1, >3 cm of N1 up-stage to N2.

Review of Nasopharyngeal Carcinoma

We review the literature on nasopharyngeal carcinoma that has been published within the past 5 years. Nasopharyngeal carcinoma is a highly morbid disease, and survival is poor. Its management remains extremely difficult, not just for otolaryngologists but for radiation oncologists and medical oncologists, as well. A clear understanding of its etiology is still lacking, but nasopharyngeal carcinoma is widely suspected to be the result of both a genetic susceptibility and exposure to environmental factors or Epstein-Barr virus infection. With no clear cause, treatment is controversial. For example, an optimal radiation regimen has not been determined, reports in the literature regarding the role of chemotherapy for advanced disease are conflicting, and treatment of local recurrences is unsettled. Still, advances in immunologic research and chemotherapy offer hope for better control of the disease. We hope that our assessment of the recent literature will provide otolaryngologists with a more clear understanding of the etiology and management of nasopharyngeal carcinoma.

A clinical staging system and treatment guidelines for maxillary osteoradionecrosis in irradiated nasopharyngeal carcinoma patients

PURPOSE

To develop a clinical staging system for maxillary osteoradionecrosis (ORN) in irradiated nasopharyngeal carcinoma (NPC) patients.

METHODS AND MATERIALS

The data of maxillary ORN cases among 1,758 irradiated NPC patients were analyzed. A staging system based on the degrees of bone exposure (E), infection (I), and bleeding (B) was developed. Correlations between various clinical parameters and stages of maxillary ORN and relationships between treatment modalities and outcomes at each stage were evaluated. Cumulative success of treatment and risk factors that affect treatment outcomes were analyzed.

RESULTS

The incidence of maxillary ORN was 2.7% (48/1,758). TNM stage of NPC (p < 0.001), radiation dose (p = 0.029), and tooth extraction (p < 0.001) appeared to have significant influences on disease severity. Success rates between conservative therapy and surgical treatment were not significantly different for Stage I ORN but differed significantly for Stage II (p = 0.013) and Stage III (p = 0.008) lesions. Grade 3 infection and bleeding significantly jeopardized treatment success (p = 0.043 and 0.015, respectively). The risk ratios of treatment failure for Grade 3 infection and bleeding were 2.523 (p = 0.034) and 3.141 (p = 0.027), respectively.

CONCLUSIONS

More serious maxillary ORN tended to occur in cases with more advanced NPC, higher radiation dose, and history of tooth extraction. Surgical treatment was usually required in Stage II and III ORN. The grades of infection and bleeding are important factors in guidance of treatment and prediction of outcomes.

Treatment of stage III-IV nasopharyngeal carcinomas by external beam irradiation and local low doses of IL-2

The therapeutic effect of intratumoural application of Interleukin-2 (IL-2) was studied in patients with stage III-IV nasopharyngeal carcinoma (NPC) that received radiotherapy. Patients with stage III-IV NPC receiving a standard treatment of 7,000 cGy external beam irradiation have a mean disease-free survival of about 1.5 years. In this paper, we describe ten of these patients who were treated with additional peritumoural and intratumoural injections with 3 x 10(4) U IL-2 on 5 days in weeks 2, 4, and 6 of the 7-weeks' irradiation period. This combined treatment group was compared with a historical group of patients treated with standard irradiation alone. Local IL-2 therapy showed a marked clinical and statistical significant improvement of disease-free survival. After 5 years, 63% of the IL-2 treated patients were disease-free versus 8% of the control patients. These results suggest that the therapeutic results of radiotherapy can be significantly improved by combining it with local IL-2 treatment. To our knowledge, this is the first clinical report showing that local IL-2 therapy is effective against an infiltrative and locally metastasizing tumour in human patients.

Involvement of both endoplasmic reticulum and mitochondria in photokilling of nasopharyngeal carcinoma cells by the photosensitizer Zn-BC-AM

Photodynamic therapy (PDT) is recently developed as an effective treatment for malignant disease. In PDT, the photosensitizer eradicates tumour by induction of apoptosis. In this study, we investigated the mechanistic actions of a recently developed second generation photosensitizer, Zn-BC-AM, on nasopharyngeal carcinoma (NPC) cells. Zn-BC-AM was found to localize in the mitochondria, endoplasmic reticulum (ER), and golgi body. Photoactivation of Zn-BC-AM loaded NPC cells resulted in a rapid collapse of mitochondrial membrane potential (Deltapsim) (15 min), followed by the release of cytochrome c (1 h), and activation of caspases-9 and -3 (4 h). Expression of ER chaperones Bip/Grp78 and Grp94, and ER resident lectin-like chaperone calnexin (CNX) was also enhanced in PDT-stressed NPC cells. Caspase-12, an important caspase involved in ER stress-induced apoptosis, was also activated. Inhibition of Ca2+ uptake into mitochondria by ruthenium red (RR) or loading the cells with EGTA-AM, an agent that buffers intracellular Ca2+ released from ER, resulted in a significant reduction of Zn-BC-AM PDT-induced cell death. These observations suggest that both ER and mitochondria are the subcellular targets of Zn-BC-AM. Effective activation of ER- and mitochondria-mediated apoptotic pathways is responsible for Zn-BC-AM PDT-induced NPC cell death.

Are dual-phase 18F-FDG PET scans necessary in nasopharyngeal carcinoma to assess the primary tumour and loco-regional nodes?

PURPOSE

This prospective study aimed to investigate the efficacy of dual-phase positron emission tomography (PET) in evaluating the loco-regional status of nasopharyngeal carcinoma (NPC).

METHODS

Eighty-four patients with newly diagnosed NPC and a fasting serum glucose level of <200 mg/dl were enrolled. [18F]fluoro-2-deoxy-D-glucose (18F-FDG) PET studies (at 40 min and 3 h after injection of 370 MBq 18F-FDG) and head and neck magnetic resonance imaging (MRI) were performed within 1 week. Diagnostic criteria for NPC comprised the histopathological findings, the joint judgments of the research team and the post-treatment outcome. Each lesion's maximum standardised uptake value (SUV) and retention index were obtained. SUV data were evaluated using a paired t test. Receiver operating characteristic curves and calculation of the area under the curve (AUC) determined the discriminative power.

RESULTS

18F-FDG PET was significantly superior to MRI in identifying lower neck NPC nodal metastasis (AUC: 1 vs 0. 972, P=0.046) and overall loco-regional metastases (AUC: 0.985 vs 0.958, P=0.036). However, 18F-FDG PET was similar to MRI in detecting primary tumour, as well as retropharyngeal, upper neck and supraclavicular nodal metastases. There was no significant difference between early phase (40 min) and delayed phase (3 h) 18F-FDG PET in the detection of primary tumours (accuracy: 100% vs 100%) or loco-regional nodal metastasis (AUC: 0.984 vs 0.985, P=0.834).

CONCLUSION

18F-FDG PET is superior to MRI in identifying lower neck nodal metastasis of NPC. Additional 3-h 18F-FDG PET contributes no further information in the detection of primary tumours or loco-regional metastatic nodes in untreated NPC patients.

Treatment of nasopharyngeal carcinoma with Epstein-Barr virus--specific T lymphocytes

Conventional treatment for nasopharyngeal carcinoma (NPC) frequently fails and is accompanied by severe long-term side effects. Since virtually all undifferentiated NPCs are associated with Epstein-Barr virus (EBV), this tumor is an attractive candidate for cellular immunotherapy targeted against tumor-associated viral antigens. We now demonstrate that EBV-specific cytotoxic T-cell (CTL) lines can readily be generated from individuals with NPC, notwithstanding the patients' prior exposure to chemotherapy/radiation. A total of 10 patients diagnosed with advanced NPC were treated with autologous CTLs. All patients tolerated the CTLs, although one developed increased swelling at the site of pre-existing disease. At 19 to 27 months after infusion, 4 patients treated in remission from locally advanced disease remain disease free. Of 6 patients with refractory disease prior to treatment, 2 had complete responses, and remain in remission over 11 to 23 months after treatment; 1 had a partial remission that persisted for 12 months; 1 has had stable disease for more than 14 months; and 2 had no response. These results demonstrate that administration of EBV-specific CTLs to patients with advanced NPC is feasible, appears to be safe, and can be associated with significant antitumor activity.

Outpatient weekly 24-hour infusional adjuvant chemotherapy of cisplatin, 5-fluorouracil, and leucovorin for high-risk nasopharyngeal carcinoma

BACKGROUND

Distant metastasis rather than locoregional recurrence is the major site of failure after adequate radiotherapy in nasopharyngeal carcinoma (NPC). The aim of this study is to evaluate the toxicity and survival of outpatient weekly 24-hour infusion adjuvant chemotherapy for NPC patients with high-risk of distant failure.

METHODS

Our definition of high-risk NPC included patients with (1) 1992 AJCC staging system of N3, T4N2, or N2 with one of nodal size > 4 cm; (2) supraclavicular node metastasis; and (3) residual disease after radiotherapy or neck relapse. From August 1994 to August 1997, 41 NPC patients matching the preceding criteria agreed to receive weekly PFL (cisplatin 25 mg/m(2), 5-fluorouracil 1250 mg/m(2), and leucovorin 120 mg/m(2)) adjuvant chemotherapy for a total of 18 weeks. Clinical data of another 88 patients with similar disease status who did not receive adjuvant chemotherapy during the same period were collected and analyzed for comparison. Survival analysis was investigated by the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

A total of 700 weekly chemotherapy doses was delivered to 41 patients. The ratio of actual/planned dose delivery was 94.9%. Grade 3-4 toxicity of adjuvant chemotherapy included leucopenia (7.3%), anemia (2.4%), thrombocytopenia (2.4%), and nausea/vomiting (2.4%). After a median follow-up of 70 months, 26.8% (11 of 41) and 47.7% (42 of 88) of patients in PFL and no adjuvant chemotherapy groups had distant metastasis (p =.0247). The 5-year metastasis-free survival rates were 71.9% for the PFL group compared with 48.4% for no adjuvant chemotherapy patients (p =.0187). The 5-year overall survival rates were 53.7% (PFL group) and 38.3% (no adjuvant chemotherapy group), respectively (p =.0666). Multivariate Cox analysis showed PFL adjuvant chemotherapy was the independent factor that predicted metastasis-free survival after adjustment for other variables.

CONCLUSIONS

Outpatient weekly 24-hour continuous infusion PFL adjuvant chemotherapy is a well-tolerated regimen with promising results in high-risk NPC patients and merits investigation in phase III studies.

Treatment of locally advanced head and neck cancer: historical and critical review

BACKGROUND

Advanced squamous cell cancers of the head and neck have traditionally been associated with high rates of morbidity and mortality. Advances in management have improved outcomes for most of these patients.

METHODS

The author reviews the historical progress in management of these difficult tumors and adds his own wide experience to describe and evaluate newer approaches to management.

RESULTS

Over the last 10 years, overall survival rates for patients with head and neck cancers have improved as has quality of life. New standards of care have been defined for patients with nasopharyngeal cancer and for those with advanced unresectable disease. Organ preservation is more commonly achieved.

CONCLUSIONS

Newer targeted therapies are likely to add to the progress that has already been achieved in the multimodality management of patients with head and neck cancers.