Identifying optimal candidates for local treatment of the primary tumor among patients with de novo metastatic nasopharyngeal carcinoma: a retrospective cohort study based on Epstein-Barr virus DNA level and tumor response to palliative chemotherapy

A head-to-head comparison of [68Ga]Ga-DOTATATE and [68Ga]Ga-FAPI PET/CT in patients with nasopharyngeal carcinoma: a single-center, prospective study

PURPOSE

We aimed to compare the staging efficiency of [68Ga]Ga-DOTATATE and [68Ga]Ga-FAPI PET/CT in nasopharyngeal carcinoma (NPC) patients.

METHODS

Thirty-nine patients with pathologically confirmed NPC were enrolled in this prospective study. Each patient underwent paired [68Ga]Ga-DOTATATE and [68Ga]Ga-FAPI PET/CT on 2 successive days. The accuracy of two PET/CT for assessing T, N, and M stages was compared by using head-and-neck MRI, histopathologic diagnosis and follow-up results as reference standards. The radiotracer uptake derived from two PETs was also compared.

RESULTS

For treatment-naïve patients, [68Ga]Ga-DOTATATE PET/CT showed identical sensitivity for the primary tumours but clearer tumor delineation induced by higher tumour-to-background (TBR) ratio (19.1 ± 8.7 vs. 12.4 ± 7.7, P = 0.003), compared with [68Ga]Ga-FAPI PET/CT. Regarding cervical lymph node (CLN) metastases, [68Ga]Ga-DOTATATE PET had significantly better sensitivity and accuracy based on neck sides (98% vs. 82%, P < 0.001; 99% vs. 88% P = 0.008), neck levels (98% vs. 78%, 99% vs. 97%; both P < 0.001) and individual nodes (89% vs. 56%, 91% vs. 76%; both P < 0.001), and higher TBR (8.1 ± 4.1 vs. 6.3 ± 3.7, P < 0.001). Additionally, [68Ga]Ga-DOTATATE PET/CT revealed higher sensitivity and accuracy for distant metastases (96% vs. 53%, 95% vs. 52%; both P < 0.001), particularly in bone metastases (99% vs. 49%, 97% vs. 49%; both P < 0.001). For post-treatment patients, [68Ga]Ga-DOTATATE PET/CT identified one more true-negative case than [68Ga]Ga-FAPI PET/CT.

CONCLUSION

[68Ga]Ga-DOTATATE PET/CT performed better than [68Ga]Ga-FAPI PET/CT in visualizing the primary tumours, detecting the metastatic lesions and identifying the local recurrence, suggesting [68Ga]Ga-DOTATATE PET/CT may be superior to [68Ga]Ga-FAPI PET/CT for NPC staging.

Long-term outcomes of metastasis-directed stereotactic body radiation therapy in metastatic nasopharyngeal carcinoma

BACKGROUND

The study aims to evaluate the outcomes of metastasis-directed stereotactic body radiation therapy (SBRT) in metastatic nasopharyngeal carcinoma (mNPC).

METHODS

We reviewed all SBRT conducted in patients with mNPC in our institution between 2013 and 2022. Systemic therapy was performed with chemotherapy with or without anti-programmed death-1 (PD-1) therapy. Local treatment delivered with ablative purpose in stereotactic setting with dose/fraction ≥5 Gy was evaluated. Kaplan-Meier analyses were used to determine the rates of local control (LC), progression-free survival (PFS), and overall survival (OS). Univariate and multivariate analyses were performed by Cox regression.

RESULTS

A total of 54 patients with 76 metastatic sites receiving SBRT were analyzed. Median follow-up was 49 months. The 3-year LC, PFS, and OS rates were 89.1%, 29.4%, and 57.9%, respectively. Adding a PD-1 inhibitor to SBRT tended to prolong median OS (50.1 vs. 32.2 months, p = 0.068). Patients receiving a biological effective dose (BED, α/β = 10) ≥ 80 Gy had a significantly longer median OS compared to those who received a lower dose (not reached vs. 29.5 months, p = 0.004). Patients with oligometastases (1-5 metastases) had a better median OS (not reached vs. 29.5 months, p < 0.001) and PFS (34.3 vs. 4.6 months, p < 0.001). Pretreatment EBV-DNA and maintenance therapy were also significant predictors for OS.

CONCLUSIONS

Metastatic NPC patients could benefit from metastases-directed SBRT in combination with systemic therapy.

Immunochemotherapy alone or immunochemotherapy plus subsequent locoregional radiotherapy in de novo metastatic nasopharyngeal carcinoma

BACKGROUND

To demonstrate whether the benefit of locoregional radiotherapy in de novo metastatic nasopharyngeal carcinoma remains in the immunotherapy era and which patients can benefit from radiotherapy.

MATERIALS AND METHODS

A total of 273 histopathology-confirmed de novo metastatic nasopharyngeal carcinoma was enrolled between May 2017 and October 2021 if receiving immunochemotherapy with or without subsequent intensity-modulated radiotherapy to the nasopharynx and neck. We compared the progression-free survival, overall survival, and safety between the two groups. Additionally, subgroup analysis was conducted and a scoring model was developed to identify suitable patients for radiation.

RESULTS

There were 95 (34.8 %) patients with immunochemotherapy alone, and 178 (65.2 %) with immunochemotherapy plus subsequent locoregional radiotherapy. With a median follow-up time of 18 months, patients with immunochemotherapy plus subsequent radiotherapy had higher 1-year progression-free survival (80.6 % vs. 65.1 %, P < 0.001) and overall survival (98.3 % vs. 89.5 %, P = 0.001) than those with immunochemotherapy alone. The benefit was retained in multivariate analysis and propensity score-matched analysis. Mainly, it was more significant in patients with oligometastases, EBV DNA below 20,200 copies/mL, and complete or partial relapse after immunochemotherapy. The combined treatment added grade 3 or 4 anemia and radiotherapy-related toxicities.

CONCLUSION

Immunochemotherapy plus subsequent locoregional radiotherapy prolonged the survival of de novo metastatic nasopharyngeal carcinoma with tolerable toxicities. A scoring model based on oligometastases, EBV DNA level, and response after immunochemotherapy could facilitate individualized management.

Effective of metastasis-directed therapy for de novo metastatic nasopharyngeal carcinoma: A propensity score matched analysis

OBJECTIVE

Our objective was to establish a prognostic model for patients with de novo metastatic nasopharyngeal carcinoma (NPC) who received chemotherapy followed by locoregional radiotherapy (LRRT) to identify candidates for metastasis-directed therapy (MDT).

METHODS

De novo metastatic NPC patients who received chemotherapy followed by LRRT were enrolled. Propensity score matching (PSM) method was used to compare overall survival (OS) for patients receiving LRRT alone and MDT plus LRRT. We developed a predictive model to predict survival and estimate the outcome of stratified therapy and identify suitable candidates for MDT.

RESULTS

A total of 107 patients received MDT plus LRRT and 178 received LRRT alone were enrolled. PSM analysis identified 107 patients in each cohort and showed that MDT plus LRRT was associated with a significant survival benefit (HR: 0.640; 95% CI, 0.29-0.956; p = 0.027). Based on five independent prognostic factors, including metastases number, serum lactate dehydrogenase, liver metastasis, C-reactive protein, and tumor response, a prognostic model was established. All patients were stratified according to the prognostic score obtained by the prognostic model. In the low-risk group, MDT plus LRRT group revealed a significant improvement for OS compared with LRRT alone group (5-year OS, 69.9% vs. 57.8%, p = 0.020). However, no significant difference was observed between MDT plus LRRT group and LRRT alone in the high-risk group (p = 0.75).

CONCLUSION

MDT plus LRRT was associated with improved OS in patients with de novo metastatic NPC, especially low-risk patients identified with a newly developed prognostic model.

Locoregional radiotherapy improves survival outcomes in de novo metastatic nasopharyngeal carcinoma treated with chemoimmunotherapy

BACKGROUND

We aimed to investigate the efficacy of locoregional radiotherapy (LRRT) in patients with de novo metastatic nasopharyngeal carcinoma (dmNPC) receiving chemotherapy combined with anti-programmed cell death receptor-1 monoclonal antibodies (anti-PD-1 mAbs) as first-line treatment and identify optimal candidates for LRRT.

MATERIALS AND METHODS

We enrolled patients with dmNPC receiving platinum-based palliative chemotherapy and anti-PD-1 mAbs followed or not followed by LRRT from four centers. The endpoints were progression-free survival (PFS), objective response rate (ORR), and overall survival (OS). We used the inverse probability of treatment weighting (IPTW) to balance the baseline characteristics of the LRRT and non-LRRT groups to minimize selection bias before comparative analyses. Multivariate analyses were carried out using the Cox proportional hazards model.

RESULTS

We included 163 patients with dmNPC (median follow-up: 22 months). The median PFS was 20 months, and the ORR was 92.0%; the median OS was not achieved. After IPTW adjustments, patients who received LRRT had a significant survival benefit over those not receiving LRRT (median PFS: 28 versus 15 months, P < 0.001). The Epstein-Barr virus DNA (EBV DNA) level after four to six cycles of anti-PD-1 mAbs [weighted hazard ratio (HR): 2.19, 95% confidence interval (CI) 1.22-3.92, P = 0.008] and LRRT (weighted HR: 0.58, 95% CI 0.34-0.99, P = 0.04) were independent prognostic factors. Patients with undetectable EBV DNA levels after four to six cycles of anti-PD-1 mAbs (early EBV DNA clearance) benefitted from LRRT (HR: 0.41, 95% CI 0.22-0.79, P = 0.008), whereas those with detectable levels did not (HR: 1.30, 95% CI 0.59-2.87, P = 0.51).

CONCLUSIONS

Palliative chemotherapy combined with anti-PD-1 mAbs followed by LRRT was associated with improved PFS in patients with dmNPC, especially for patients with early EBV DNA clearance.

Development of a prognostic model to identify the metastatic nasopharyngeal carcinoma patients who may benefit from chemotherapy combination PD-1 inhibitor

Background

We aimed to establish a prognostic model to identify suitable candidates for chemotherapy combination PD-1 inhibitor in metastatic nasopharyngeal carcinoma (NPC) patients.

Patients and methods

In this retrospective study, we included 524 patients (192 patients treated with chemotherapy combination PD-1 inhibitor and 332 received chemotherapy alone as first-line regimen) with metastatic NPC between January 2015 and March 2021. We developed a prognostic model to predict progression-free survival (PFS). A model-based trees approach was applied to estimate stratified treatment effects using prognostic scores and two well-matched risk groups (low-risk and high-risk) were created using propensity score matching.

Results

A prognostic nomogram was established with good accuracy for predicting PFS (c-index values of 0.71; 95% confidence interval, 0.66-0.73). The survival curves were significantly different between low-risk and high-risk groups (median PFS: 9.8 vs. 22.8 months, P < 0.001, respectively). After propensity matching analysis, chemotherapy combination PD-1 inhibitor was significantly associated with superior PFS as compared with chemotherapy alone (median PFS, 10.6 versus 9.3 months, P = 0.016) in the high-risk group. However, no significant difference between chemotherapy combination PD-1 inhibitor and chemotherapy was observed (P = 0.840) in the low-risk groups.

Conclusions

Our novel prognostic model was able to stratify patients with metastatic NPC into low-risk or high-risk groups and identify candidates for PD-1 inhibitor therapy. These results are expected to be confirmed by a prospective clinical trial.

Comparison of induction chemotherapy combined with concurrent chemoradiotherapy versus concurrent chemoradiotherapy alone in Lymph-Node-Stage III nasopharyngeal carcinoma based on propensity score-matching

PURPOSE

To explore the role of induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) versus CCRT alone in patients diagnosed with N3 nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

A total of 787 patients with newly diagnosed N3 NPC treated with IC + CCRT or CCRT alone were included. Progression-free survival (PFS) was the primary endpoint. We balanced variables using propensity score matching (PSM). Kaplan-Meier curves with log-rank tests were applied to evaluate the survival condition of each group. Independent prognostic factors were identified using the Cox regression analysis.

RESULTS

PSM assigned 228 patients to IC + CCRT and CCRT alone groups. Survival analysis for the matched data set showed that IC + CCRT achieved better survival outcomes compared with CCRT alone, and significant difference was observed in 5-year PFS [74.8% (95%CI 69.2 ∼ 80.9%) vs 65.4% (95%CI 59.4 ∼ 72.0%), P = 0.008], 5-year OS [(77.4%(95%CI 71.9 ∼ 83.3%) vs66.3%(95%CI 60.3 ∼ 72.9%), P = 0.005)] and 5-year distant metastasis-free survival (DMFS)[(81.8%(95%CI 76.7 ∼ 87.2%) vs72.4%(95%CI 66.7 ∼ 78.7%), P = 0.007)] between the two treatment groups. In multivariate analysis, IC + CCRT remained an independent protective factor for PFS (adjusted HR, 0.603; 95% CI, 0.433-0.841; P = 0.003), OS (adjusted HR, 0.568; 95% CI, 0.406-0.793; P < 0.001), and DMFS (adjusted HR, 0.541; 95% CI, 0.364-0.805; P = 0.002).

CONCLUSION

More chemotherapy should be considered in patients with N3 NPC because of its ability to improve survival time. This could be from the use of IC or adjuvant metronomic chemotherapy.

M1 stage subdivisions based on 18F-FDG PET-CT parameters to identify locoregional radiotherapy for metastatic nasopharyngeal carcinoma

Purpose

To establish a risk classification of de novo metastatic nasopharyngeal carcinoma (mNPC) patients based on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET-CT) radiomics parameters to identify suitable candidates for locoregional radiotherapy (LRRT).

Methods

In all, 586 de novo mNPC patients who underwent ¹⁸F-FDG PET-CT prior to palliative chemotherapy (PCT) were involved. A Cox regression model was performed to identify prognostic factors for overall survival (OS). Candidate PET-CT parameters were incorporated into the PET-CT parameter score (PPS). Recursive partitioning analysis (RPA) was applied to construct a risk stratification system.

Results

Multivariate Cox regression analyses revealed that total lesion glycolysis of locoregional lesions (LRL-TLG), the number of bone metastases (BMs), metabolic tumor volume of distant soft tissue metastases (DSTM-MTV), pretreatment Epstein-Barr virus DNA (EBV DNA), and liver involvement were independent prognosticators for OS. The number of BMs, LRL-TLG, and DSTM-MTV were incorporated as the PPS. Eligible patients were divided into three stages by the RPA-risk stratification model: M1a (low risk, PPS_low + no liver involvement), M1b (intermediate risk, PPS_low + liver involvement, PPS_high + low EBV DNA), and M1c (high risk, PPS_high + high EBV DNA). PCT followed by LRRT displayed favorable OS rates compared to PCT alone in M1a patients (p < 0.001). No significant survival difference was observed between PCT plus LRRT and PCT alone in M1b and M1c patients (p > 0.05).

Conclusions

The PPS-based RPA stratification model could identify suitable candidates for LRRT. Patients with stage M1a disease could benefit from LRRT.

Which evaluation criteria of the short-term efficacy can better reflect the long-term outcomes for patients with nasopharyngeal carcinoma?

•

1D, 2D, and 3D measurements were all significantly correlated with PTV measurement.

•

The 1D measurement more closely agreed with the PTV measurement than the 2D and 3D measurements.

•

1D tumor response assessment of the short-term efficacy can reflect the PFS for patients with nasopharyngeal carcinoma.

Purpose

To compare the consistency of one-dimensional Response Evaluation Criteria in Solid Tumors (1D-RECIST), two-dimensional WHO criteria (2D-WHO), and three-dimensional (3D) measurement for therapeutic response assessment of nasopharyngeal carcinoma (NPC).

Materials and methods

Retrospective data of 288 newly diagnosed NPC patients were reviewed. Tumor size was assessed on magnetic resonance imaging (MRI) according to the 1D-RECIST, 2D-WHO, and 3D measurement criteria. Agreement between tumor responses was assessed using unweighted k statistics. The receiver operating characteristic (ROC) curve was used to determine the optimal cut-off point of the PTV. The Kaplan–Meier method and Cox regression were used for the survival analysis.

Results

The optimal cut-off point of the PTV for progression-free survival (PFS) was 29.6%. Agreement with PTV measurement was better for 1D measurement than for 2D and 3D measurements (kappa values of 0.646, 0.537, and 0.577 for 1D, 2D, and 3D measurements, respectively; P < 0.05). The area under the curve of the 1D measurement (AUC=0.596) was similar to that of the PTV measurement (AUC=0.621). Compared with 2D and 3D measurements, 1D measurement is superior for predicting prognosis in NPC (C-index of 0.672, 0.663, and 0.646 were for 1D, 2D, and 3D measurements, respectively; P < 0.005). Survival analysis showed that patients with non-responders had worse prognosis (P < 0.05).

Conclusions

The 1D measurement more closely agreed with the PTV measurement than the 2D and 3D measurements for predicting therapeutic responses in NPC. Therefore, we recommend using the less time-consuming 1D-RECIST criteria in routine clinical practice.

Addition of chemoradiotherapy to palliative chemotherapy in de novo metastatic nasopharyngeal carcinoma: a real-world study

Background

To determine whether concurrent chemotherapy is necessary during locoregional radiotherapy (RT) after palliative chemotherapy (PCT) in patients with de novo metastatic nasopharyngeal carcinoma (mNPC).

Methods

A total of 746 patients with mNPC from 2000 to 2017 at our hospital were retrospectively reviewed. Among them, 355 patients received PCT followed by RT. Overall survival (OS) and progression-free survival (PFS), including locoregional progression-free survival (LRPFS) and distant progression-free survival (DPFS) were estimated with the Kaplan–Meier method and log-rank test. Cox proportional-hazards models, landmark analyses, propensity score matching, and subgroup analyses were used to address confounding.

Results

Of the patients included in our study, 192 received radiotherapy alone after PCT (PCT + RT), and 163 received concurrent chemoradiotherapy after PCT (PCT + CCRT). The prognosis of PCT + CCRT was significantly better than that of PCT + RT (5 year OS, 53.0 vs 36.2%; P = 0.004). After matching, the 5 year OS rates of the two groups were 55.7 and 39.0%, respectively (P = 0.034) and the median DPFS were 29.4 and 18.7 months, respectively (P = 0.052). Multivariate Cox regression analysis indicated that PCT + CCRT was an independent favorable prognostic factor (P = 0.009). In addition, conducting concurrent chemoradiotherapy after 4–6 cycles of PCT or conducting concurrent chemotherapy with single-agent platinum was associated with significant survival benefit in the matched cohort (5 year OS rate, 60.4 or 57.4%, respectively). The survival difference between groups remained significant when evaluating patients who survived for ≥ 1 year (P = 0.028).

Conclusions

The optimal treatment strategy of mNPC is the combination of PCT followed by concurrent chemoradiotherapy. More specifically, concurrent chemoradiotherapy with single-agent platinum after 4–6 cycles of PCT is suggested.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02464-7.

First-Line Immunochemotherapy Versus Palliative Chemotherapy Plus Definitive Radiation Therapy for de novo Metastatic Nasopharyngeal Carcinoma: A Matched Cohort Study

BACKGROUND

The combined use of immune checkpoint inhibitors (ICIs) with palliative chemotherapy (PCT) is a promising first-line treatment for de novo metastatic nasopharyngeal carcinoma (mNPC). However, the efficacy of ICIs with PCT vs PCT with definitive radiation therapy (DRT) remain unclear.

METHODS

Patients with mNPC who received first-line immunochemotherapy (ICI + PCT) or PCT + DRT were included. Propensity score matching (PSM) was applied to balance potential confounders between patients who did and did not undergo DRT (at a ratio of 1:1). Progression free survival (PFS) and overall survival (OS) were compared between the 2 groups using a log-rank test and Cox proportional hazard model.

RESULTS

Among all participants, 149 received ICI + PCT. After PSM, 149 patients were included in the PCT + DRT group. First-line immunochemotherapy was associated with significantly improved PFS (median 9.0 months vs 12.0 months, P < .001) and OS (median 12.5 months vs 19.9 months, P < .001). Subgroup analysis revealed that tumor response to immunochemotherapy, metastatic organs, and number of metastatic sites potentially affected the efficacy of DRT after first-line immunochemotherapy.

CONCLUSION

Compared with PCT + DRT, first-line immunochemotherapy was associated with improved PFS and OS in patients with mNPC but not in patients with unfavorable tumor response and metastasis involving the liver, distant nodes, or multiple sites.

Survival Effects of Radiotherapy on Patients Newly Diagnosed with Distant Metastatic Nasopharyngeal Carcinoma in Non-High-Incidence Areas

Purpose

To analyze the effects of radiotherapy and its timing on the survival and safety of patients with newly diagnosed distant metastatic NPC in non-high-incidence areas.

Patients and Methods

We retrospectively analyzed 94 newly diagnosed NPC patients with distant metastatic admitted to our hospital from January 2011 to June 2018. They were divided into three groups: no radiotherapy group received chemotherapy alone, early radiotherapy group was combined with radiotherapy during 1 to 3 cycles of chemotherapy, and late radiotherapy group was combined with radiotherapy after 4–6 cycles of chemotherapy were effective. The efficacy and side effects of the three groups were compared, and the prognostic factors were analyzed.

Results

The 6-month, 1-year and 2-year PFS were 53.6%, 14.3% and 3.6% in no radiotherapy group, 71.0%, 38.7% and 19.4% in early radiotherapy group, 88.6%, 48.6% and 22.9% in late radiotherapy group; the radiotherapy groups were better than the no radiotherapy group, and the difference was statistically significant (P < 0.017). The 1-year, 2-year and 3-year OS were 75.0%, 32.1% and 0 in no radiotherapy group, 77.4%, 54.8% and 12.9% in early radiotherapy group, 85.7%, 71.4% and 31.4% in late radiotherapy group; the radiotherapy groups were better than the no radiotherapy group, and the differences were statistically significant (P < 0.017). There was no significant difference in OS and PFS between the two radiotherapy groups. Univariate and multivariate analysis showed that HBV (P = 0.031), number of metastases (P = 0.002), liver metastases (P = 0.038), radiotherapy (P < 0.001) and treatment response (P = 0.011) were related to OS. There was no significant difference in the incidence of adverse events (P > 0.017).

Conclusion

Early and late combined radiotherapy had similar clinical efficacy and both prolonged PFS and OS for patients with newly diagnosed distant metastatic NPC in non-high-risk areas. If chemotherapy response is expected to be poor, radiotherapy can be received early.

Nasopharyngeal carcinoma: an evolving paradigm

The past three decades have borne witness to many advances in the understanding of the molecular biology and treatment of nasopharyngeal carcinoma (NPC), an Epstein-Barr virus (EBV)-associated cancer endemic to southern China, southeast Asia and north Africa. In this Review, we provide a comprehensive, interdisciplinary overview of key research findings regarding NPC pathogenesis, treatment, screening and biomarker development. We describe how technological advances have led to the advent of proton therapy and other contemporary radiotherapy approaches, and emphasize the relentless efforts to identify the optimal sequencing of chemotherapy with radiotherapy through decades of clinical trials. Basic research into the pathogenic role of EBV and the genomic, epigenomic and immune landscape of NPC has laid the foundations of translational research. The latter, in turn, has led to the development of new biomarkers and therapeutic targets and of improved approaches for individualizing immunotherapy and targeted therapies for patients with NPC. We provide historical context to illustrate the effect of these advances on treatment outcomes at present. We describe current preclinical and clinical challenges and controversies in the hope of providing insights for future investigation.

Prognostic Factors for Overall Survival in Nasopharyngeal Cancer and Implication for TNM Staging by UICC: A Systematic Review of the Literature

This study aims to identify prognostic factors in nasopharyngeal carcinoma (NPC) to improve the current 8th edition TNM classification. A systematic review of the literature reported between 2013 and 2019 in PubMed, Embase, and Scopus was conducted. Studies were included if (1) original clinical studies, (2) ≥50 NPC patients, and (3) analyses on the association between prognostic factors and overall survival. The data elements of eligible studies were abstracted and analyzed. A level of evidence was synthesized for each suggested change to the TNM staging and prognostic factors. Of 5,595 studies screened, 108 studies (44 studies on anatomical criteria and 64 on non-anatomical factors) were selected. Proposed changes/factors with strong evidence included the upstaging paranasal sinus to T4, defining parotid lymph node as N3, upstaging N-category based on presence of lymph node necrosis, as well as the incorporation of non-TNM factors including EBV-DNA level, primary gross tumor volume (GTV), nodal GTV, neutrophil-lymphocyte ratio, lactate dehydrogenase, C-reactive protein/albumin ratio, platelet count, SUVmax of the primary tumor, and total lesion glycolysis. This systematic review provides a useful summary of suggestions and prognostic factors that potentially improve the current staging system. Further validation studies are warranted to confirm their significance.

Trajectories of EBV DNA and identifying the potential long-term survivors in metastatic nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is highly incident in southern China. Distant metastasis is the leading cause of death in NPC patients. However, the phenotypical feature of this patient population is largely undefined. The current study aimed to categorize metastatic NPC patients into novel subgroups based on their EBV DNA trajectories. In this retrospective study, 446 eligible patients with metastatic NPC treated at Sun Yat-Sen University Cancer Center between 2012 and 2016 were analyzed. Using a mixture model analysis, we identified distinct trajectories based on longitudinal EBV DNA measurements. We evaluated their associations with metastatic NPC mortality using Cox regression analysis. The two-class trajectory model provided the best fit, in which 272 patients were classified as non-sustained EBV DNA class and 174 patients as sustained EBV DNA class. After a median follow-up of 60.8 months, the median OS was 61.7 months in the sustained EBV DNA clearance class versus 20.0 months in the non-sustained EBV DNA clearance class (P<0.001). Compared with patients in the non-sustained EBV DNA clearance class, patients in the sustained EBV DNA clearance class demonstrated superior PFS (HR, 3.238; 95% CI, 2.601-4.032; P<0.001). Forty-three patients experienced disease-free for longer than 36 months, defined as long-term survivors (LTS). Notably, 41 patients were presented in the sustained EBV DNA clearance class (95.3%), along with only 2 patients in the non-sustained EBV DNA clearance class. Collectively, we identified two EBV DNA trajectory sub-phenotypes of patients with metastatic NPC, providing more reliable survival information for physicians and patients during their informed decision-making process.

Effects of locoregional radiotherapy in de novo metastatic nasopharyngeal carcinoma: A real-world study

•

Locoregional radiotherapy can prolong OS for patients with de novo metastatic nasopharyngeal carcinoma.

•

Nasopharyngeal carcinoma patients with oligometastic disease can benefit from locoregional radiotherapy rather than polymetastatic disease.

Background

To evaluate the value of locoregional radiotherapy (LRRT) in de novo metastatic nasopharyngeal carcinoma (dmNPC) and identify predictive factors for additional LRRT after palliative chemotherapy (PCT).

Methods

Overall survival (OS) was the primary endpoint. Patients who underwent PCT and LRRT were categorized as the PCT+LRRT group; patients who only received palliative chemotherapy were categorized as the PCT group. Oligometastatic diseases (OMD) was defined as ≤5 metastatic lesions and ≤2 metastatic organs.

Results

A total of 168 patients were included for this study. The median OS of patients in the PCT+LRRT group was significantly higher than those in the PCT group (57 months vs. 22 months, P<0.001). Multivariate analyses (MVA) showed that LRRT (HR=0.533, 95% CI: 0.319–0.889, P = 0.016) and OMD (HR=0.548, 95% CI: 0.331–0.907, P = 0.019) were independent prognostic factors for dmNPC. Furthermore, Kaplan–Meier analyses showed that the 3-year OS of patients who received LRRT was significantly better than those who did not receive LRRT in the OMD subgroup (66.3% vs. 25.2%, P<0.001). While, the 3-year OS of patients who received LRRT and without LRRT was no different in the polymetastatic disease (PMD) subgroup (38.9% vs.11.5%, P = 0.115). MVA showed that LRRT was a favorable prognosticator in the OMD subgroup (HR=0.308, 95% CI: 0.159–0.598; P<0.001), and not a favorable prognosticator in the PMD subgroup (HR=0.510, 95% CI: 0.256–1.014, P = 0.055).

Conclusions

LRRT has the potential to prolong OS in NPC patients with de novo OMD. These results suggest that OMD is a potential indicator for filtering beneficiaries from LRRT.

A systematic review and recommendations on the use of plasma EBV DNA for nasopharyngeal carcinoma

INTRODUCTION

Nasopharyngeal carcinoma (NPC) is an endemic malignancy in Southeast Asia, particularly Southern China. The classical non-keratinising cell type is almost unanimously associated with latent Epstein-Barr virus (EBV) infection. Circulating plasma EBV DNA can be a useful biomarker in various clinical aspects, but comprehensive recommendations and international guidelines are still lacking. We conducted a systematic review of all original articles on the clinical application of plasma EBV DNA for NPC; we further evaluated its strengths and limitations for consideration as standard recommendations.

METHODS

The search terms 'nasopharyngeal OR nasopharynx', and 'plasma EBV DNA OR cell-free EBV OR cfEBV' were used to identify full-length articles published up to December 2020 in the English literature. Three authors independently reviewed the article titles, removed duplicates and reviewed the remaining articles for eligibility.

RESULTS

A total of 81 articles met the eligibility criteria. Based on the levels of evidence and grades of recommendation assessed, it is worth considering the inclusion of plasma EBV DNA in screening, pre-treatment work-up for enhancing prognostication and tailoring of treatment strategy, monitoring during radical treatment, post-treatment surveillance for early detection of relapse, and monitoring during salvage treatment for recurrent or metastatic NPC. One major limitation is the methodology of measurement requiring harmonisation for consistent comparability.

CONCLUSIONS

The current comprehensive review supports the inclusion of plasma EBV DNA in international guidelines in the clinical aspects listed, but methodological issues must be resolved before global application.

Identifying the optimal candidates for locoregional radiation therapy in patients with de novo metastatic nasopharyngeal carcinoma

BACKGROUND

To evaluate the value of locoregional radiation therapy (LRRT) in de novo metastatic nasopharyngeal carcinoma (mNPC) and identify suitable candidates for additional LRRT after palliative chemotherapy (PCT).

METHODS

Patients with de novo mNPC received platinum-based chemotherapy for a minimum of four cycles with or without definitive LRRT via intensity-modulated radiation therapy (IMRT) were all candidates for this study.

RESULTS

A total of 168 patients were included for this analysis. Additional LRRT was associated with significantly longer median OS (69.5 vs. 17.8 months, p < 0.001) when compared with PCT alone. However, this survival benefit of LRRT was only reflected in patients with oligometastatic diseases (90.8 vs. 17 months, p < 0.001), but not for those with polymetastatic disease (p = 0.86).

CONCLUSIONS

Additional LRRT after PCT may only improve OS for oligometastatic patients. For patients with polymetastatic disease, intensive systemic treatment such as the combination of immunotherapy and adequate PCT might be necessary.

Nomograms for predicting survival outcomes in intensity-modulated radiotherapy era of nasopharyngeal carcinoma: A study based on Epstein-Barr virus DNA biological responses

BACKGROUND

Treatment of nasopharyngeal carcinoma (NPC) is evolving toward Intensity-modulated radiotherapy (IMRT) era, which requires patient-specific reestimation of survival outcomes in modern health care.

METHODS

A total of 488 detectable pre-treatment Epstein-Barr virus (EBV) DNA patients (stage II-IVa) treated with induction chemotherapy (IC) and IMRT were examined (training set, n = 325; validation set, n = 163).

RESULTS

Concurrent chemotherapy (CC) was still an independent prognosticator for overall survival (OS) and progression-free survival (PFS). Both nomograms included age, T classification, N classification, post-IC EBV DNA, and CC. Predictions correlated well with observed 3-/5-year OS and PFS. The concordance index was 0.776 (95% confidence interval (CI) 0.69-0.86) for OS and 0.742 (95% CI 0.65-0.83) for PFS in the validation cohort. The nomograms can successfully classify patients into low- and high-risk groups.

CONCLUSION

The validated nomograms provided useful prediction of OS and PFS for detectable pre-treatment EBV DNA patients with NPC in IMRT era.

Prognostic model for risk stratification of de novo metastatic nasopharyngeal carcinoma patients treated with chemotherapy followed by locoregional radiotherapy

BACKGROUND

There is no clinically applicable prognostic model designed for patients with de novo metastatic nasopharyngeal carcinoma (mNPC) treated with chemotherapy followed by locoregional radiotherapy (LRRT). We sought to develop a predictive tool of overall survival for individualized prediction and risk stratification in this heterogeneous patient population.

PATIENTS AND METHODS

A total of 244 eligible patients with de novo mNPC, who were treated with platinum-based first-line chemotherapy followed by LRRT, were included in this retrospective study. We divided patients into the training and validation sets based on the date of initial treatment, with 152 patients treated between 2008 and 2013 comprising the training set for model development and 92 patients treated at a later time (2014 to 2015) forming the validation set. We applied Cox proportional hazards model to examine factors associated with overall survival (OS). We developed and subsequently validated a prognostic model to predict OS. We assessed the performance of this prognostic model and stratified patients based on prognostic scores obtained from this proposed model.

RESULTS

The median OS of the entire cohort was 60.9 months. C-creative protein, number of metastatic sites, liver metastasis, post-treatment Epstein-Barr virus DNA, and response of metastasis were significantly associated with OS. A prognostic model for individual survival prediction was developed and graphically represented as a nomogram. The model showed favorable discrimination (C-index: 0.759), predictive accuracy [time dependent area under the curve (tAUC) at 5 years: 0.800], and calibration, and was further validated in an independent dataset. A risk stratification derived from the model can stratify these patients into three prognostic subgroups with significantly different survival.

CONCLUSION

We developed and validated a prognostic model that exhibited adequate performance in individualized prediction and risk stratification for patients with de novo mNPC treated with chemotherapy followed by LRRT.

Observer agreement and accuracy of 18F-sodium fluoride PET/computed tomography in the diagnosis of skull-base bone invasion and osseous metastases in newly diagnosed nasopharyngeal carcinoma

OBJECTIVES

To evaluate the interobserver agreement and the diagnostic performance in F-sodium fluoride (F-NaF) PET/computed tomography (CT) for the detection of skull-base bone invasion (SBBI) and osseous metastases in patients with newly diagnosed nasopharyngeal carcinoma (NPC).

METHODS

One hundred seventeen patients with newly diagnosed NPC between 2017 and 2019 who underwent F-NaF PET/CT was in included. Two experienced observers independently evaluated the F-NaF PET/CT of SBBI and osseous metastases on a patient level using a two-category scale present on a dichotomous scale, respectively. On a patient level, the diagnostic performance was calculated using a sensitivity analysis.

RESULTS

The interobserver agreement on a patient level of SBBI and osseous metastases were perfect on a patient-level (κ: 0.85), (κ: 0.808), respectively. On a lesion level of detection of osseous metastases, the observers agreed on the number as well as the location of osseous metastases in 101 (86.3%) patients. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of detection of SBBI and osseous metastases were ranged 0.911-0.962, 0.921-0.974, 0.932-0.957, 0.962-0.986, and 0.841-0.923, and ranged 0.917-0.958, 0.899-0.957, 0.906-0.949, 0.863-0.936, and 0.939-0.970, respectively.

CONCLUSION

The interobserver agreement of F-NaF PET/CT for the detection of SBBI and osseous metastases in patients with NPC were both very high among trained observers. Moreover, the diagnostic performance of NaF PET/CT was satisfactory, rendering NaF PET/CT a robust tool in the diagnostic armamentarium.

Development of a Prognostic Model to Identify the Suitable Definitive Radiation Therapy Candidates in de Novo Metastatic Nasopharyngeal Carcinoma: A Real-World Study

PURPOSE

We aimed to develop an accurate prognostic model to identify suitable candidates for definitive radiation therapy (DRT) in addition to palliative chemotherapy (PCT) among patients with de novo metastatic nasopharyngeal carcinoma (mNPC).

METHODS AND MATERIALS

Patients with de novo mNPC who received first-line PCT with or without DRT were included. Overall survival for patients who received PCT alone versus PCT plus DRT was estimated using inverse probability of treatment weighting-adjusted survival analyses. We developed and validated a prognostic model to predict survival and stratify risks in de novo mNPC. A model-based trees approach was applied to estimate stratified treatment effects using prognostic scores obtained from the prognostic model and to identify suitable DRT candidates. Dominance analysis was used to determine the relative importance of each predictor of receiving DRT.

RESULTS

A total of 460 patients were enrolled; 244 received PCT plus DRT and 216 received PCT alone. The 6-month conditional landmark, inverse probability of treatment weighting-adjusted Cox regression analysis showed that PCT plus DRT was associated with a significant survival benefit (hazard ratio: 0.516; 95% confidence interval, 0.403-0.660; P < .001). A prognostic model based on 5 independent prognostic factors, including serum lactate dehydrogenase, number of metastatic sites, presence of liver metastasis, posttreatment Epstein-Barr virus DNA level, and response of metastases to chemotherapy was developed and subsequently validated. Prognostic scores obtained from the prognostic model were used for risk stratification and efficacy estimation. High-risk patients identified using the proposed model would not benefit from additional DRT, whereas low-risk patients experienced significant survival benefits. Socioeconomic factors, including insurance status and education level, played an important role in receipt of DRT.

CONCLUSIONS

Additional DRT after PCT was associated with increased overall survival in patients with de novo mNPC, especially low-risk patients identified with a newly developed prognostic model.

Intensive Local Radiotherapy Is Associated With Better Local Control and Prolonged Survival in Bone-Metastatic Nasopharyngeal Carcinoma Patients

Objective: To compare the survival outcomes brought by different radiation dose schedules to bone lesions and different chemotherapy regimens in bone metastatic nasopharyngeal carcinoma (NPC).

Background: The current treatment strategy for bone metastatic NPC patients was empirically given and poorly studied before. It is of necessity to optimize the treatment for bone metastasis to enhance the therapeutic effect and increase the proportion of long-term survived patients.

Methods: Three hundred patients who received chemoradiotherapy from 2002 to 2018 were involved in the study. Demographics, laboratory results, and detailed treatment plans were recorded. Radiotherapy plans were classified into three categories based on the intensity, and the survival analysis was performed using log-rank test. Multivariable analysis was made by the Cox proportional regression model.

Results: Patients who received 60–75 Gy/30–35 fractions of radiation to the metastatic bones had significantly longer bone relapse-free survival (BRFS) (HR, 0.53, 95% CI, 0.37–0.78, P = 0.003), overall survival (OS) (HR, 0.63, 95% CI, 0.46–0.84, P = 0.007), and progression-free survival (PFS) (HR, 0.80, 95% CI, 0.67–0.95, P = 0.041). The administration of paclitaxel, cisplatin and 5-fluorouracil regimen was also associated with better BRFS (HR, 0.27, 95% CI, 0.10–0.75, P = 0.007), PFS (HR, 0.60, 95% CI, 0.42–0.87, P = 0.007), and OS with borderline significance (HR, 0.54, 95% CI, 0.29–1.03, P = 0.058). In multivariable analysis, the post-treatment EBV DNA level and radical radiation dose were proved as independent prognostic factors for both BRFS and OS.

Conclusions: Radiotherapy to metastatic bones with palliative dose prescription should not be considered in bone metastatic NPC patients. TPF chemotherapy regimen might help to improve the survivals in NPC patients but failed to be an independent protective factor.

Optimal cumulative cisplatin dose in nasopharyngeal carcinoma patients based on plasma Epstein-Barr virus DNA level after induction chemotherapy

PURPOSE

This study aimed to elucidate the optimal cumulative cisplatin dose (CCD) for concurrent chemoradiotherapy (CCRT) according to the post-induction chemotherapy (IC) plasma Epstein-Barr virus (EBV) DNA level.

RESULTS

EBV DNA was detected and undetected in 179 and 370 patients, respectively. Of the entire cohort, 73/549 (13.3%) patients received a total CCD ≥ 160 mg/m² and 476/549 (86.7%) patients, <160 mg/m². CCD enhancement was not associated with a survival benefit in patients with undetected EBV DNA after IC. However, among patients with post-IC detectable EBV DNA, higher 3-year PFS and locoregional relapse-free survival (LRFS) rates were observed in those who received a CCD ≥ 160 mg/m². Multivariate analysis also showed CCD was an independent prognostic factor for PFS and LRFS in patients with post-IC detectable EBV DNA.

CONCLUSIONS

CCD enhancement was not associated with a survival benefit in patients with undetected EBV DNA after IC. However, among patients with post-IC detectable EBV DNA, those receiving ≥160 mg/m² CCD showed significantly improved 3-year PFS and LRFS.

METHODS

NPC patients (549) treated with IC and CCRT were included. Prognosis was assessed using a multivariate Cox proportional hazards model. Furthermore, grade 1-4 toxicities were compared between different CCD groups.

The role of capecitabine as maintenance therapy in de novo metastatic nasopharyngeal carcinoma: A propensity score matching study

Background

Capecitabine was previously used as a second‐line or salvage therapy for metastatic nasopharyngeal carcinoma (NPC) and has shown satisfactory curative effect as maintenance therapy in other metastatic cancers. This study aimed to explore the role of capecitabine as maintenance therapy in de novo metastatic NPC patients with different plasma Epstein‐Barr virus (EBV) DNA levels before treatment.

Methods

We selected de novo metastatic NPC patients treated with locoregional radiotherapy (LRRT) for this retrospective study. The propensity score matching (PSM) was applied to balance potential confounders between patients who underwent capecitabine maintenance therapy and those who did not with a ratio of 1:3. Overall survival (OS) was the primary endpoint. The association between capecitabine maintenance therapy and survival was assessed using the log‐rank test and a Cox proportional hazard model.

Results

Among all patients eligible for this study, 64 received capecitabine maintenance therapy after LRRT. After PSM, 192 patients were identified in the non‐maintenance group. In the matched cohort, patients treated with capecitabine achieved a higher 3‐year OS rate compared with patients in the non‐maintenance group (68.5% vs. 61.8%, P = 0.037). Multivariate analysis demonstrated that capecitabine maintenance therapy was an independent prognostic factor. In subgroup analysis, 3‐year OS rate was comparable between the maintenance and non‐maintenance groups in patients with high pretreatment EBV DNA levels (˃30,000 copies/mL) (54.8% vs. 45.8%, P = 0.835), whereas patients with low pretreatment EBV DNA levels (≤30,000 copies/mL) could benefit from capecitabine maintenance therapy in OS (90.0% vs. 68.1%, P = 0.003).

Conclusion

Capecitabine maintenance therapy may be superior to non‐maintenance therapy in prolonging OS for de novo metastatic NPC patients with pretreatment EBV DNA ≤ 30,000 copies/mL.

Oral Maintenance Chemotherapy Using S-1/Capecitabine in Metastatic Nasopharyngeal Carcinoma Patients After Systemic Chemotherapy: A Single-Institution Experience

Background

In this study, we retrospectively evaluated a series of metastatic nasopharyngeal carcinoma (mNPC) patients who received oral maintenance chemotherapy using S-1/capecitabine after systemic chemotherapy and local radiation therapy, and aimed to explore potential efficient treatment strategies for this subset of patients.

Patients and Methods

Thirty-seven patients with mNPC (19 newly diagnosed metastatic patients and 18 metastatic cases after definitive chemoradiotherapy) who received the treatment strategies mentioned above were analyzed.

Results

After a median follow-up time of 37 months, the 3-year progression-free survival and overall survival (OS) rates were 47.6% and 87.7%, respectively. The median time to progression was 27.6 months, while the median OS was not reached at time of last follow-up. The most common acute adverse events were hematological and gastrointestinal toxicity, and all were tolerable and curable.

Conclusion

Oral maintenance chemotherapy using S-1/capecitabine in mNPC patients after systemic chemotherapy could yield a superb outcome. Further multicenter prospective clinical trials are warranted.

Characteristic And Novel Therapeutic Strategies Of Nasopharyngeal Carcinoma With Synchronous Metastasis

Nasopharyngeal carcinoma (NPC) is rare in Western countries, but its incidence in China and Southeast Asia is notably high. NPC shows a high rate of distant metastasis including metachronous metastasis (mmNPC, metastasis after definitive chemo-radiotherapy) and synchronous metastasis (smNPC, metastasis at initial diagnosis). 4–10% of patients would be diagnosed as smNPC annually, and the survival outcomes of these patients are quite poor. As with few clinical trials exclusively focusing on this population, treatment on smNPC is not unified and many problems remain unsolved. To date, systematic chemotherapy (CT) still remains a fundamental treatment in smNPC. Although no randomized trial has been conducted to compare different CT regimens in smNPC, gemcitabine and taxanes in combination with platinum seem optimal in first-line setting. In second-line CT, there is no consensus: mono-chemotherapy with drugs such as gemcitabine, taxanes or capecitabine could be taken into consideration. Immunotherapy based on checkpoint inhibitors shows promising efficacy both in first-line and in the following lines of therapy. In addition to CT, local therapy in smNPC is also very important. Locoregional radiotherapy (RT) for primary tumor in combination with CT could strikingly increase OS with acceptable toxicities. And local treatment, such as surgery and RT, for metastatic lesions could bring extra survival benefit in patients with solitary or limited metastases. Overall, the present study provides an overview of the literature on the various studies of smNPC.

Nasopharyngeal carcinoma

Nasopharyngeal carcinoma is characterised by distinct geographical distribution and is particularly prevalent in east and southeast Asia. Epidemiological trends in the past decade have shown that its incidence has declined gradually but progressively, and mortality has been reduced substantially. These findings probably reflect lifestyle and environmental changes, enhanced understanding of the pathogenesis and risk factors, population screening, advancements in imaging techniques, and individualised comprehensive chemoradiotherapy strategies. In particular, plasma Epstein-Barr virus (EBV) DNA has been used for population screening, prognostication, predicting treatment response for therapeutic adaptation, and disease surveillance. Moreover, the widespread application of intensity-modulated radiotherapy and optimisation of chemotherapy strategies (induction, concurrent, adjuvant) have contributed to improved survival with reduced toxicities. Among the existing developments in novel therapeutics, immune checkpoint therapies have achieved breakthroughs for treating recurrent or metastatic disease and represent a promising future direction in nasopharyngeal carcinoma.