Cetuximab concurrent with IMRT versus cisplatin concurrent with IMRT in locally advanced nasopharyngeal carcinoma: A retrospective matched case-control study

Cetuximab Plus Concurrent Radiotherapy in Patients With Nasopharyngeal Carcinoma

BACKGROUND/AIM

Several reports have evaluated the efficacy and safety of concurrent radiotherapy with cetuximab (BRT) in patients with nasopharyngeal carcinoma (NPC). Combination therapy with cetuximab can be a treatment option for NPC. Although clinical data regarding the efficacy and safety of BRT without induction chemotherapy (ICT) or adjuvant chemotherapy is essential for the development of new therapeutic strategies, such data are rarely reported.

PATIENTS AND METHODS

We retrospectively investigated a series of patients with NPC treated in our institution to evaluate the efficacy and safety of BRT. Eleven patients with newly diagnosed NPC were identified from an inpatient database from July 2015 to April 2018. Seven patients who received BRT were reviewed.

RESULTS

All patients completed BRT without cessation of treatment. Six (85.7%) patients achieved a complete response and one (14.3%) achieved stable disease. The response rate was 85.7%. All patients with ≤T3 disease achieved a complete response. Both patients with T3 disease developed local recurrence, and one of the four patients with T1-2 disease developed distant metastases. The 1- and 3-year overall survival rates were 85.7% and 47.6%, respectively. The most common adverse events (AEs) were pharyngeal mucositis (100%), radiation dermatitis (100%), anorexia (28.6%), weight loss (28.6%), acneiform rash (28.6%), and dry mouth (28.6%). Grade 3 AEs were pharyngeal mucositis (42.9%), radiation dermatitis (28.6%), and anorexia (14.3%). No grade 4/5 AEs were observed.

CONCLUSION

BRT for NPC was tolerable, but our findings suggest that BRT without induction chemotherapy or adjuvant chemotherapy is insufficient at least for ≥T3 disease.

Real-world evidence of cisplatin versus carboplatin in patients with locally advanced nasopharyngeal carcinoma receiving concurrent chemoradiotherapy: A multicenter analysis

BACKGROUND

Though concurrent chemoradiotherapy (CCRT) with cisplatin remains a standard of care for patients with locally advanced nasopharyngeal carcinoma (LA-NPC), carboplatin has alternatively been used without sufficient supportive evidences. Thus, we evaluated an efficacy and tolerability of carboplatin CCRT compared with cisplatin in LA-NPC patients.

METHODS

Patients with LA-NPC treated with CCRT were identified through the Thai multicenter head and neck cancer database. Patient tolerability and survival were analyzed and compared between regimens. Survivals were calculated by using the Kaplan-Meier method, and compared by the log-rank test. A p-value of <0.05 was considered statistically significant.

RESULTS

A total of 135 of 980 patients (13.8%) were treated with carboplatin. Patients treated with carboplatin were significantly associated with older age (p < 0.001), smoking (p = 0.003), more comorbidity (p = 0.014), kidney disease (p = 0.016), and lower baseline creatinine clearance (p < 0.001). Intensity-modulated radiation therapy was used significantly more in the cisplatin group than carboplatin group (p < 0.001). Patients who received carboplatin were associated with delay (p = 0.049) and hospitalization (p = 0.006), whereas cisplatin CCRT had more dose reduction (p = 0.001). Patients treated with cisplatin had CCRT interruption from grade 3-4 mucositis (p = 0.019) more than carboplatin, whereas carboplatin had more grade 3-4 thrombocytopenia (p < 0.001). The 5-year overall survival (OS) of patients treated with cisplatin and carboplatin was 59% and 49%, respectively (p = 0.128). Cisplatin or carboplatin CCRT was not a significant predictor for OS and locoregional recurrence-free survival in multivariate analysis.

CONCLUSIONS

Carboplatin CCRT provided acceptable efficacy and tolerability profiles in real-world practice. Carboplatin should be considered as an alternative regimen, particularly in cisplatin-ineligible patients with LA-NPC treated with CCRT.

A meta-analysis of cisplatin-based concurrent chemoradiotherapy with or without cetuximab for locoregionally advanced nasopharyngeal carcinoma

BACKGROUND

It is unclear whether cetuximab (CTX) plus cisplatin-based concurrent chemoradiotherapy (CCRT) delivers equivalent or improved results over standard CCRT in locoregionally advanced nasopharyngeal carcinoma (NPC).

METHODS

The strategy involved searching the PubMed, Embase, Cochrane Library, and Web of Science. Pooled hazard ratios (HRs) for overall survival (OS), distant metastasis-free survival (DMFS), locoregional relapse-free survival (LRFS), and disease-free survival (DFS), and pooled risk ratios for adverse events were meta-analyzed.

RESULTS

In all, 1744 patients in 5 clinical trials were included in the analysis. Compared with CCRT group, CTX plus CCRT significantly improved DFS (HR = 0.59, 95% confidence interval [CI]: 0.41-0.86, P = .006) and distant metastasis failure-free survival (HR = 0.54, 95% CI: 0.38-0.76, P = .0004), rather than OS (HR = 0.70, 95% CI: 0.44-1.09, P = .12) and local-regional failure-free survival (HR = 0.82, 95% CI: 0.54-1.22, P = .33).

CONCLUSIONS

CTX plus CCRT might achieve higher DFS and DMFS with no significant difference in OS and LRFS. CTX plus CCRT group was associated with more grade 3-4 skin rash, mucositis and dermatitis. Large randomized trials were urgent to fully explore the usefulness of this treatment in the locally advanced NPC patients.

Cetuximab in the management of nasopharyngeal carcinoma - a narrative review

BACKGROUND

Concurrent chemotherapy with radiotherapy is the standard treatment for locoregionally advanced nasopharyngeal cancer. Cetuximab can be used in the treatment of head and neck squamous cell carcinoma. However, the randomised studies that led to approval for its use in this setting excluded nasopharyngeal cancer. In the context of limited data for the use of cetuximab in nasopharyngeal cancer in the medical literature, this review aimed to summarise the current evidence for its use in both primary and recurrent or metastatic disease.

METHOD

A literature search was performed using the keywords 'nasopharyngeal neoplasm', 'cetuximab' and 'Erbitux'.

RESULTS

Twenty studies were included. There were no randomised phase III trials, but there were nine phase II trials. The use of cetuximab in the treatment of nasopharyngeal carcinoma has been tested in various settings, including in combination with induction chemotherapy and concurrent chemoradiotherapy, and in the palliative setting.

CONCLUSION

There is no evidence of benefit from the addition of cetuximab to standard management protocols, and there is some evidence of increased toxicity. There is more promise for its use in metastatic or locally recurrent settings. This review draws together the existing evidence and could provide a focus for future studies.

Cetuximab in combination with chemoradiotherapy for nasopharyngeal carcinoma: A meta-analysis

AIMS AND OBJECTIVES

The aims and objectives of this study are to investigate the efficacy and safety of chemoradiotherapy (CCRT) with or without cetuximab in nasopharyngeal carcinoma (NPC).

METHODS

We searched the Cochrane Library, PubMed, Embase, CNKI, VIP, Chinese biomedicine literature database, and WANFANG database for relevant articles. The methodological quality of included studies was evaluated, and data were analyzed using RevMan 5.0 software.

RESULTS

Ten relevant articles (783 patients) were identified. The results were complete response rate; the response rate was significantly better in the cetuximab plus CCRT (C225+CCRT) group than the CCRT group. The partial response and 3-year-overall survival rates were not significantly different between the two groups. Regarding adverse effects, myelosuppression was observed in the CRRT group and the C225+CCRT group; the main toxicity was mucositis and rash, but no significant statistical difference was observed.

CONCLUSION

The combination of cetuximab and CCRT was more effective for NPC than CCRT alone and had no serious side effects.

Combination treatment with cetuximab in advanced nasopharyngeal carcinoma patients: a meta-analysis

Purpose

Cetuximab, an anti-epidermal growth factor receptor monoclonal antibody, carries the potential for combination treatment against nasopharyngeal carcinoma (NPC). We conducted a meta-analysis to assess the possible benefits and safety between the combination treatment with cetuximab and conventional treatment in NPC patients. Skin toxicity (ST) associated with additional cetuximab was evaluated as well.

Methods

We performed a systematic search (PubMed, Embase, Cochrane library, China National Knowledge Infrastructure, and WanFang Data) for studies comparing combination treatment with cetuximab versus conventional treatment in NPC patients. The selected studies included completely or partly reported clinical outcomes including survivals, complete and partial responses, and adverse reactions (ST). The pooled HR, relative risk (RR), and respective 95% CI were estimated by using fixed effects model or random effects model.

Results

A total of 23 relevant studies with available data were included in the final analysis. According to the pooled data, combination treatment with cetuximab showed improved efficacy on increased objective response rate (studies with cetuximab treatment: RR: 1.39, 95% CI: 1.29–1.50; concurrent chemoradiotherapy with or without cetuximab: RR: 1.39, 95% CI: 1.25–1.54) and prolonged survival (studies with cetuximab treatment: the pooled HR for OS was 0.70, 95% CI: 0.55–0.89; concurrent chemoradiotherapy with or without cetuximab: the pooled HR for OS was 0.64, 95% CI: 0.49–0.84) compared with conventional treatment. Moreover, the improved efficacy was invariably accompanied by an increased occurrence of ST (studies with cetuximab treatment: RR: 2.46, 95% CI: 1.81–3.34; concurrent chemoradiotherapy with or without cetuximab: RR: 1.84, 95% CI: 1.02–3.31). However, the majority of adverse reactions exhibited similar occurrence rates between the different treatments.

Conclusion

Patients with NPC receiving additional cetuximab treatment can benefit more from this systemic comprehensive therapy, while the efficiency of conventional treatment for NPC is limited. ST associated with cetuximab may be used as a potential on-treatment marker to guide treatment with cetuximab against NPC.

High-Dose Static and Dynamic Intensity-Modulated Radiotherapy Combined with Chemotherapy for Patients with Locally Advanced Nasopharyngeal Carcinoma Improves Survival and Reduces Brainstem Toxicity

BACKGROUND Intensity-modulated radiotherapy (IMRT) is the standard treatment for patients with nasopharyngeal cancer (NPC). However, the dose-volume criteria for adjacent anatomically normal organs at risk (OARs) remain controversial. The aim of this study was to evaluate the effects of higher than conventional doses of static and dynamic IMRT on the locoregional control of NPC, patient survival, and brainstem radiation toxicity. MATERIAL AND METHODS Patients (n=186) with stage III and stage IVa NPC underwent high-dose static and dynamic IMRT treatment (68-76.96 Gy) with or without chemotherapy for 34-57 days. Overall survival (OS), the presence of distant metastases, and brainstem toxicity were assessed. One-year, three-year, and five-year follow-up was performed. RESULTS High-dose IMRT alone or in combination with chemotherapy resulted in a 100% objective response rate and significantly improved OS rates, with one-year, three-year, and five-year OS rates of 94.1%, 89.8%, and 88.2%, respectively. The local recurrence rate (17.6%), and distant metastasis to the lung, liver, and bone (17.2%), and mortality (n=22) were reduced. Chemotherapy was the only factor that was significantly correlated with patient survival. Brainstem toxicity was reduced in patients treated with static IMRT (0.07%) and dynamic IMRT (0.08%). There were 26 additional factors that were not found to significantly affect brainstem toxicity. CONCLUSIONS High-dose static or dynamic IMRT combined with chemotherapy improved survival and reduces distal metastasis with a very low occurrence of brainstem toxicity in patients with locally advanced NPC. These findings might provide therapeutic guidance for clinicians when planning optimal dose-volume IMRT parameters.

The Efficacy and Safety of Anti-epidermal Growth Factor Receptor Monoclonal Antibodies in Nasopharyngeal Carcinoma: Literature-based Meta-analyses

Background: Anti-epidermal growth factor receptor monoclonal antibodies (anti-EGFR mAbs), such as cetuximab and nimotuzumab have been used in the treatment of nasopharyngeal carcinoma (NPC), yet their efficacy and safety are undetermined. Materials and Methods: We performed two meta-analyses based on systematic searches of PubMed, EMBASE, the Cochrane Library and SinoMed: comparison 1 (standard therapy plus mAbs vs. standard therapy) and comparison 2 (radiotherapy plus concurrent mAbs vs. concurrent chemoradiotherapy) to explore the treatment value of anti-EGFR mAbs in NPC. Primary outcomes were overall survival (OS) and disease-free survival (DFS); secondary outcomes, locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and grade 3 and above acute adverse events. Results: Four randomized controlled trials and thirteen observational studies were eligible. Comparison 1 (twelve studies): adding mAbs to standard therapy (radiotherapy or chemoradiotherapy) significantly improved OS (HR, 0.51; 95% CI, 0.39-0.66) and DFS (HR, 0.68; 95% CI, 0.54-0.86), but increased the frequency of skin rashes and mucositis. Comparison 2 (six studies): OS (HR, 1.17; 95% CI, 0.81-1.70) and DFS (HR, 1.16; 95% CI, 0.86-1.57) were not significantly different when mAbs replaced conventional cytotoxic chemotherapy concurrently with radiotherapy, with fewer hematological, gastrointestinal and renal toxicities and more skin rashes in the mAb group. Conclusion: We recommend anti-EGFR mAbs enhance-but should not replace-current treatment paradigms for locoregionally advanced NPC. Further evidence from phase III clinical trials is required.

Cetuximab or Nimotuzumab Versus Cisplatin Concurrent with Radiotherapy for Local-Regionally Advanced Nasopharyngeal Carcinoma: a Meta-analysis

Background: It is unclear whether Cetuximab (CTX) or Nimotuzumab (NTZ) concurrent with radiotherapy delivers equivalent or improved results with fewer toxicities over standard cisplatin (CDDP) concurrent with radiotherapy in locally advanced nasopharyngeal carcinoma (NPC). Methods: The strategy involved searching the PubMed, Embase, Cochrane Library, China National Knowledge Internet Web, Wanfang and Chinese Biomedical databases. Controlled clinical trials that compared concurrent CTX/NTZ with radiotherapy versus CDDP with radiotherapy in local-regionally advanced NPC were included. Results: In all, 1,239 patients in six clinical trials were included in the analysis. The hazard ratios (HRs) between the CTX/NTZ and CDDP groups were 1.01 (95% confidence interval (CI) 0.63-1.64), 1.06 (95% CI 0.50-2.25), 1.04 (95% CI 0.61-1.76), and 1.05 (95% CI 0.73-1.50) for overall survival, local-regional failure-free survival, distant metastasis failure-free survival, and disease-free survival, respectively. Significant differences were found in the incidences of grade 3-4 anaemia [Risk ratio (RR) 0.11 95% CI 0.02-0.58], grade 3-4 neutropenia (RR 0.23 95% CI 0.12- 0.44), grade 3-4 thrombocytopenia (RR 0.31 95% CI 0.12- 0.79), and grade 3-4 vomiting (RR 0.04 95% CI 0.00-0.29) in favour of the CTX/NTZ group. However, the patients in the CTX/NTZ group experienced a higher incidence of grade 3-4 skin rash (RR 6.45 95% CI 3.84-10.84). Conclusions: Regarding the efficacy and side effects, the combination of CTX / NTZ and radiotherapy may be an alterative treatment regimen of standard CDDP concurrent with radiotherapy in local-regionally advanced NPC, especially in patients who cannot tolerate or who refuse chemotherapy.

Effectiveness of Cetuximab in Combination with Concurrent Chemoradiotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma: A 1:2 Propensity Score-matched Analysis

Background: This study aimed to compare concurrent chemoradiotherapy (CCRT) plus cetuximab (C) with CCRT alone in locoregionally advanced nasopharyngeal carcinoma(NPC).

Methods: A total of 682 locoregionally advanced NPC patients who had undergone chemoradiotherapy with or without cetuximab were included. Propensity score-matching method was used to match patients. Progression-free survival (PFS), overall survival (OS), locoregional relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were compared between the two treatment arms.

Results: After matching, 225 patients were identified for the analysis. Compared to CCRT, CCRT plus C was associated with significantly improved 3-year PFS (83.7% vs 71.9%, P = 0.036), LRFS (98.6% vs 90.2%, P = 0.034) but not OS (91.4% vs 85.4%, P = 0.117). Among patients with T4 and/or N3 category, CCRT plus C significantly prolonged 3-year PFS (81.0% vs 61.4%, P = 0.022) and increased 3-year OS (88.0% vs 77.9%, P = 0.086). No significant differences were observed between CCRT plus C and CCRT alone groups with regard to 3-year PFS, OS, LRFS and DMFS rates in stage III patients. Acute oral and oropharyngeal mucositis during radiotherapy were more common in the CCRT plus C than that in CCRT, but late toxicities were comparable.

Conclusions: This study reveals that patients with locoregionally advanced NPC could benefit from the addition of cetuximab to CCRT, and this therapeutic gain mainly originated from T4 and/or N3 subgroup although suffering more acute moderate to severe toxicities.

Intensity-modulated radiotherapy plus nimotuzumab with or without concurrent chemotherapy for patients with locally advanced nasopharyngeal carcinoma

Objective

This study aimed to evaluate the safety and efficacy of intensity-modulated radiotherapy (IMRT) plus nimotuzumab with or without concurrent chemotherapy (CCT) for patients with locally advanced nasopharyngeal carcinoma (LA-NPC).

Patients and methods

A total of 50 newly diagnosed patients with LA-NPC treated at the Affiliated Hospital of Jiangnan University between November 2011 and January 2017 were retrospectively analyzed. All patients received the combined treatment modality of nimotuzumab plus IMRT. Nimotuzumab was administered concurrently with IMRT at a weekly dose of 200 mg. Neoadjuvant, concurrent or adjuvant chemotherapy with the doublet regimen of taxanes (docetaxel or paclitaxel) plus platinum (cisplatin or nedaplatin) were administered. Among the 50 patients, 43 (86.0%) received ≥6 cycles of nimotuzumab (median 7 cycles, range 2-14 cycles) and 29 (58.0%) received two cycles of CCT with docetaxel plus nedaplatin.

Results

With a median follow-up of 28.0 months, the 2-year progression-free survival (PFS) and overall survival were 83.29% (95% confidence interval [CI]: 67.93%-91.72%) and 97.67% (95% CI: 84.62%-99.67%), respectively. Both univariate and multivariate analyses revealed that cycles of nimotuzumab were significantly associated with PFS. Patients who received ≥6 cycles of nimotuzumab showed a better PFS than those receiving <6 cycles (P=0.006), whereas the addition of CCT failed to improve PFS. Oral mucositis was the most common adverse event, which was recorded as grade 3-4 in 18 (36.0%) patients. Besides, two (4.0%) patients experienced nimotuzumab-related anaphylaxis, and no skin rash was found in any patient. Subgroup analysis revealed that the patients who received CCT had more grade 3-4 adverse events as compared to those who did not receive CCT (62.1% vs 33.3%, P=0.045).

Conclusion

The regime of nimotuzumab plus IMRT for the treatment of LA-NPC was well tolerated, with encouraging survival data, and it could be an effective treatment alternative for patients with LA-NPC. Further clinical trials are needed to confirm these findings.

Concurrent chemoradiotherapy with or without cetuximab for stage II to IVb nasopharyngeal carcinoma: a case-control study

Background

This study aimed to evaluate the long-term outcome and toxicities in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) treated by concurrent chemoradiotherapy (CCRT) with/without adding cetuximab.

Methods

A total of 62 patients treated with CCRT plus cetuximab were matched with 124 patients treated with CCRT alone by age, sex, pathological type, T category, N category, disease stage, radiotherapy (RT) technique, Epstein-Barr virus (EBV) DNA levels, and Eastern Cooperative Oncology Group (ECOG). Overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were assessed using the Kaplan–Meier method and log-rank test. Treatment toxicities were clarified and compared between two groups.

Results

A total of 186 well-balanced stage II to IV NPC patients were retrospectively analyzed (median follow-up, 76 months). Compared to CCRT alone, adding cetuximab resulted in more grade 3 to 4 radiation mucositis (51.6% vs. 23.4%; P < 0.001). No differences were found between the CCRT + cetuximab group and the CCRT group in 5-year OS (89.7% vs. 90.7%, P = 0.386), 3-year PFS (83.9% vs. 88.7%, P = 0.115), the 3-year LRFS (95.0% vs. 96.7%, P = 0.695), and the 3-year DMFS (88.4% vs 91.9%, P = 0.068). Advanced disease stage was the independent prognostic factor predicting poorer OS and PFS.

Conclusion

Adding cetuximab to CCRT did not significantly improve benefits in survival in stage II to IV NPC and exacerbated acute mucositis and acneiform rash. Further investigations are warranted.

Cetuximab or nimotuzumab plus intensity-modulated radiotherapy versus cisplatin plus intensity-modulated radiotherapy for stage II-IVb nasopharyngeal carcinoma

To compare intensity-modulated radiotherapy (IMRT) with cisplatin (CDDP) versus cetuximab (CTX) and nimotuzumab (NTZ) for Stage II-IVb Nasopharyngeal Carcinoma (NPC). A total of 1,837 patients with stage II-IV_b NPC who received IMRT plus CTX or NTZ, or CDDP between January 2009 and December 2013 were included in the current analysis. Using propensity scores to adjust for potential prognostic factors, a well-balanced cohort of 715 patients was created by matching each patient who underwent IMRT plus concomitant NTZ/CTX with four patients who underwent IMRT plus concomitant CDDP (1:4). Efficacy and safety were compared between the CTX/NTZ and CDDP groups of this well-balanced cohort. Furthermore, we conducted multivariate analysis and subgroup analysis based on all the 1,837 eligible cases. There was no significant difference between CTX/NTZ group and CDDP group in terms of DFS (3-year, 86.7% vs. 86.2%, p > 0.05), LRRFS (96.2% vs. 96.3%, p > 0.05), DMFS (91.1% vs. 92.3%, p > 0.05) and OS (91.7% vs. 91.9%, p > 0.05). Subgroup analysis demonstrated a significant interaction effect between patients with IMRT plus CTX/NTZ and N3 node stage on LRRFS with the highest risk of loco-regional relapse (HR 8.85, p = 0.001). Significantly increased hematologic toxicities, gastrointestinal reactions were observed in the CDDP group (p < 0.05). Patients of 3.4-4.7% experienced severe hematologic toxicities during the treatment with concomitant CTX and NTZ. Increased rate of CTX related-skin reaction and mucositis was observed in the CTX group. CTX/NTZ used concurrently with IMRT may be comparable to those of the standard CDDP-IMRT combination for maximizing survival for patients with stage II-IVb NPC.

Cyclooxygenase-2 expression is positively associated with lymph node metastasis in nasopharyngeal carcinoma

BACKGROUND

Accumulating evidence has demonstrated that cyclooxygenase-2 (COX-2) is involved in head and neck cancers, especially in nasopharyngeal carcinoma (NPC). However, the association between COX-2 expression and lymph node metastasis in NPC remains uncertain. This systematic review and meta-analysis meta-analysis investigated the relationship between COX-2 expression and lymph node metastasis and other signs of disease progression in NPC.

METHODS

Previously published studies assessing COX-2 expression and lymph node metastasis in NPC were identified in four English databases and three Chinese ones (Pubmed, Embase, Cochrane Database of Systematic Reviews, Web of Science, China National Knowledge Infrastructure, Wanfang, Vip Journal Integration Platform) up to November 2016. Quality of all eligible studies was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). Pooled odds ratios (OR) and their 95% confidence intervals (95%CI) were calculated with fixed-effects or random-effects model to evaluate the effects of COX-2 expression on lymph node metastasis.

RESULTS

A total of 27 studies with 1797 NPC patients met the inclusion criteria. The expression of COX-2 was significantly higher in patients with nasopharyngeal carcinoma than those without the carcinoma, with a combined OR of 21.17 (95%CI = 15.02-29.85, I2 = 35.1%, Pheterogeneity = 0.070). A statistically significant association between COX-2 expression and lymph node metastasis in NPC patients, with an OR of 4.44 (95%CI = 3.46-5.70, I2 = 38.3%, Pheterogeneity = 0.024), and with other indicators of disease progression. Subgroup analyses based on COX-2 assay and staging criteria of TNM showed no significant heterogeneity.

CONCLUSIONS

The results suggest that expression of COX-2 is associated with lymph node metastasis and disease progression in NPC, indicating a potential role in evaluation of prognosis and in treatment decisions. COX-2 inhibitors have potential in the treatment of NPC that should be further investigated.