Longitudinal post-radiotherapy plasma Epstein-Barr virus DNA trends inform on optimal risk stratification in endemic nasopharyngeal carcinoma

Updates on Treatments and Management of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a unique head and neck cancer, where the endemic subtype is strongly associated with Epstein-Barr virus (EBV) infection, whereas emerging data suggest that a subset of nonendemic NPC may be associated with human papillomavirus (HPV) infection. Nonetheless, treatment advances have been driven by clinical trials conducted in endemic NPC, investigating optimal sequencing of chemotherapy and immune checkpoint inhibitors with radiotherapy for locoregionally advanced disease. The preference for induction chemotherapy (IC) in these patients has also led to evolution in the concept of radiotherapy target delineation. Because of its association with EBV, plasma EBV DNA is an archetypal biomarker for endemic NPC, and it is being explored for precise stratification and treatment individualization in several ongoing trials. In the space of recurrent or metastatic-NPC, with the advent of platinum-doublet chemotherapy and anti-PD-1 antibody as the new standard of care, several trials are investigating new immunotherapeutic combinations, bispecific antibodies, and antibody-drug conjugates that have demonstrated promise in early phase trials. An important advance for NPC in 2025 is the update of the 9th version of the TNM staging system, which has introduced several key changes, including downgrading of the TNM stage groupings for localized disease, and splitting of metastatic NPC into IVA and IVB based on the number of metastatic lesions. These revisions would have implications for the treatment and design of future trials. These advances are also relevant to nonendemic NPC, where evidence is inconclusive whether this disease responds differently to current treatments compared with endemic NPC.

Personalising Nasopharyngeal Cancer: Systemic Therapy and Radiotherapy Treatment Volumes

Nasopharyngeal carcinoma (NPC) is sensitive to chemotherapy and radiotherapy, with current treatment recommendations largely based on TNM-stage. Radiotherapy remains the backbone of treatment for NPC. Over the past decades, the addition of concurrent chemotherapy to radiotherapy for early-stage disease, and the combination of induction chemotherapy (IC) or adjuvant chemotherapy (AC) with chemoradiotherapy vs chemoradiotherapy alone for advanced disease have led to substantial improvements in survival of patients with NPC. Nonetheless, in the era of precision oncology, there is growing recognition that patients with NPC are clinically heterogeneous even within the same stage-group, and future advances must focus on individualisation of systemic therapy and radiotherapy. In this review, we summarised the published evidence on EBV DNA as a biomarker for clinical stratification and treatment response in NPC, and discussed some of the ongoing clinical trials of EBV DNA-directed personalisation of systemic therapy in locoregionally-advanced disease. Next, we assessed the evidence concerning individualised radiotherapy strategies for target volume delineation of the primary tumour and cervical nodes that ought to be based on individual tumour extent and IC response (for locoregionally-advanced NPC) as opposed to the historical one-size fits all approach. In the same vein, radiotherapy dose de-escalation may be considered in good responders to IC, whereas for the poor responders, altered fractionation or dose escalation may be required to target resistant disease. These concepts are particularly relevant in the era of combinatorial immune checkpoint blockade therapy with radiotherapy, where preservation of circulating immune cells is crucial to evoke immune-mediated antitumour cytotoxicity.

Advances in individualization of systemic treatment for locoregionally advanced nasopharyngeal carcinoma: a systematic review

BACKGROUND

The optimal treatment strategy (radiotherapy with induction, concurrent or adjuvant chemotherapy) for patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC) remains to be addressed. Identifying biomarkers related to precise prognostic risk stratification and treatment benefits gained have been explored in recent years.

METHODS

We carried out a systematic review of the published literature covering these topics. Of 3732 references screened, 26 articles were found eligible for inclusion.

RESULTS

Regarding the issue of treatment pathway in LA-NPC, induction chemotherapy is usually preferred over adjuvant chemotherapy. It is paramount to stress patient selection to identify those cases at high risk of relapse requiring systemic intensification. Concerning a role for Epstein-Barr virus (EBV) DNA-based personalized therapy, EBV DNA and its kinetics in plasma potentially represents a robust prognostic marker after (chemo)radiotherapy, but it is necessary to standardize test and cut-off levels.

CONCLUSIONS

This systematic review provides an overview of biomarker-guided systemic treatment designed to improve prognosis, including key aspects of current guidelines, biomolecular signature aspects and potential limitations between applicability to cancer treatment in endemic regions versus non-endemic regions.

Impact of the radiotherapy rhythm on prognosis in nasopharyngeal carcinoma

OBJECTIVE

The role of chronoradiobiology in nasopharyngeal carcinoma (NPC) has not been fully elucidated. We sought to investigate the impact of radiotherapy rhythm on the survival outcomes of individuals to explore a chronomodulated radiation strategy to improve prognosis of NPC.

METHODS

A cohort comprising non-metastatic NPC patients subjected to intensity-modulated radiotherapy at Fujian Cancer Hospital between Jan. 2016 and Dec. 2019 was assembled. Rhythmic fluctuation of radiotherapy (RFRT) was quantified based on the temporal distribution of radiation delivery. Cox proportional hazard model was performed to explore the impact of radiotherapy rhythm on all-cause mortality. The maximally selected rank statistics method was employed to discern an optimal cutoff. Sensitivity analyses were conducted to ensure the robustness of observed associations.

RESULTS

Our analysis encompassed 2245 patients, with a median follow-up duration of 55 months, during which 315 individuals succumbed. Multivariate Cox regression analysis unveiled a significant correlation between prolonged RFRT and heightened mortality risk in NPC patients (HR, 1.17, 95% CI, 1.07-1.27, p < .001), a relationship robust to comprehensive adjustment for confounding variables. A cutoff value of 3 h was selected for potential clinical application, beyond which patients exhibited markedly poorer survival outcomes. Subgroup analyses consistently underscored the directional consistency of observed effects.

CONCLUSION

Our study sheds light on the potential advantages of scheduling radiotherapy sessions at consistent times. These findings have implications for optimizing radiotherapy schedules and warrant further investigation into personalized chronotherapy approaches in NPC management.

Liquid biopsy with plasma Epstein-Barr virus DNA characterizes biological relapse for the prediction of cancer recurrence in non-disseminated nasopharyngeal carcinoma

PURPOSE

To investigate whether a bounce in plasma Epstein-Barr virus (EBV) DNA during posttreatment surveillance of nasopharyngeal carcinoma (NPC) informs the risk of clinical recurrence and its implication for early therapeutic intervention.

METHODS

950 non-disseminated NPC patients with completed remission in 3 months after treatment were retrospectively screened. Detectable EBV DNA with no evidence of clinical relapse during follow-up was deemed as DNA bounce. The diagnostic and prognostic performance of EBV DNA bounce was assessed for subsequent failures.

RESULTS

Tumor recurrence occurred in 6.6 %, 10.1 % and 65.8 % in the group with persistently negative EBV DNA, single positive test and ≥ 2 positive tests, respectively. EBV DNA bounce over twice was associated with worse disease-free survival (DFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) than the other two groups. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for the prediction of recurrence were 0.56, 0.95, 0.66, 0.93 and 0.90 using two positive tests, which were hence deemed as biological relapse. Serial cutoffs (EBV DNA 1 ≥ 40 copies/ml or EBV DNA 2 ≥100 copies/ml) further defined a high-risk subgroup with an eventual recurrence rate of 77.9 % and 3-year DFS of merely 20.5 %. Prophylactic medical intervention with capecitabine or S1 significantly improved the 3-year DFS when compared to those with observation.

CONCLUSIONS

The earliest two positive tests of EBV DNA represent a biomarker of biological relapse that allows early detection of clinical recurrence in EBV-related NPC. For high-risk biological relapse, preemptive intervention provides potential survival benefits.