Prognostication of Half-Life Clearance of Plasma EBV DNA in Previously Untreated Non-metastatic Nasopharyngeal Carcinoma Treated With Radical Intensity-Modulated Radiation Therapy

Radiation therapy with phenotypic medicine: towards N-of-1 personalization

In current clinical practice, radiotherapy (RT) is prescribed as a pre-determined total dose divided over daily doses (fractions) given over several weeks. The treatment response is typically assessed months after the end of RT. However, the conventional one-dose-fits-all strategy may not achieve the desired outcome, owing to patient and tumor heterogeneity. Therefore, a treatment strategy that allows for RT dose personalization based on each individual response is preferred. Multiple strategies have been adopted to address this challenge. As an alternative to current known strategies, artificial intelligence (AI)-derived mechanism-independent small data phenotypic medicine (PM) platforms may be utilized for N-of-1 RT personalization. Unlike existing big data approaches, PM does not engage in model refining, training, and validation, and guides treatment by utilizing prospectively collected patient's own small datasets. With PM, clinicians may guide patients' RT dose recommendations using their responses in real-time and potentially avoid over-treatment in good responders and under-treatment in poor responders. In this paper, we discuss the potential of engaging PM to guide clinicians on upfront dose selections and ongoing adaptations during RT, as well as considerations and limitations for implementation. For practicing oncologists, clinical trialists, and researchers, PM can either be implemented as a standalone strategy or in complement with other existing RT personalizations. In addition, PM can either be used for monotherapeutic RT personalization, or in combination with other therapeutics (e.g. chemotherapy, targeted therapy). The potential of N-of-1 RT personalization with drugs will also be presented.

Clinical relevance of plasma EBV DNA as a biomarker for nasopharyngeal carcinoma in non-endemic areas: A multicenter study in southwestern China

BACKGROUND

Numerous clinical studies have validated plasma EBV DNA as a reliable biomarker for nasopharyngeal carcinoma (NPC) screening, tumor load monitoring, and prognosis prediction in endemic regions. However, the clinical relevance of plasma EBV DNA as a biomarker for NPC in non-endemic areas is still unclear.

METHOD

The pretreatment plasma EBV DNA of 1405 newly diagnosed NPC patients from three major regional hospitals in non-endemic areas were analyzed retrospectively. The medical records of 244 age- and gender-matched healthy individuals were reviewed. EBV DNA was detected using Polymerase Chain Reaction (PCR). Based on the baseline of 400 and 0 copies/mL, the distribution characteristics of the pretreatment EBV DNA load in different clinical stages and geographic regions were analyzed. The diagnostic value of pretreatment plasma EBV DNA for NPC with two baselines was evaluated using the ROC curve.

RESULTS

NPC patients had a significantly higher pretreatment EBV DNA level than healthy controls (P＜0.001). Pretreatment EBV DNA was closely associated with clinical and TNM stages in non-endemic areas, as it was in endemic areas. However, when 400 copies/mL set as the detection baseline, the sensitivity and specificity for NPC diagnosis were 40.8 % and 100 %, respectively (AUC = 0.704, cut off = 200.5 copies/mL). This sensitivity was lower than that reported in endemic regions (41.5 % - 97.1 %). Lower sensitivity may result in false negatives, missing diagnoses during NPC screening. Further investigation revealed that 39.7 % (558/1405) of NPC patients had detectable EBV DNA and S amplification curves. Optimizing the detection limit to 0 copies/mL, the sensitivity could be improved to 80.5 % (AUC = 0.901).

CONCLUSIONS

In non-endemic areas, the clinical significance of plasma EBV DNA as a biomarker for NPC was restricted due to the low detection limit of 400 copies/mL. More efficient nucleic acid extraction and detection methods are needed to optimize the detection limit and increase the clinical application of plasma EBV DNA for NPC.

Epstein-Barr virus dynamics and its prognostic impact on nasopharyngeal cancers in a non-endemic region

Background

Epstein-Barr virus (EBV) DNA quantification in nasopharyngeal cancer (NPC) is an indicator of the tumour burden, stage and survival. Although EBV dynamics in endemic regions has been extensively studied and reported, the data from non-endemic regions is sparse. This study attempts to investigate the EBV dynamics in NPC patients from a non-endemic region and also to identify the factors impacting the outcomes.

Materials and methods

This was a prospective observational study conducted at a tertiary care centre in South India and enrolled patients with non-metastatic, biopsy proven NPC, who were suitable for radical chemo-radiotherapy with or without induction chemotherapy. Two blood samples, one prior to initiation of any anticancer treatment, and second at 6 weeks post treatment, were collected to quantify EBV DNA using real-time quantitative polymerase chain reaction. Antibodies against EBV viral capsid antigen (EBV VCA IgM), EBV Early Antigen (EBV EA IgG) and EBV Nuclear Antigen (EBV EBNA IgG) were also measured in the sample. The impact of EBV dynamics on the outcomes was then analysed.

Results

The study included a total of 35 patients. Thirty-three had identifiable EBV DNA (94.3%) and a histological diagnosis of non-keratinising undifferentiated type of squamous cell carcinoma. There was no correlation between the EBV DNA and anti-EBV antibodies. There was a significant association between composite stage and pre-treatment DNA titre (p = 0.030). The mean EBV DNA titre was lower for patients with no clinically demonstrable disease at last follow-up and the reduction in EBV DNA titres was significant (p = 0.020) for those patients who remained disease free.

Conclusion

Plasma EBV DNA is an accurate and reliable biomarker for NPC for WHO type 2 and 3 tumours even in non-endemic regions.

The Promise of Circulating Tumor DNA in Head and Neck Cancer

As the seventh most common cancer globally, head and neck cancers (HNC) exert considerable disease burden, with an estimated 277,597 deaths worldwide in 2020 alone. Traditional risk factors for HNC include tobacco, alcohol, and betel nut; more recently, human papillomavirus has emerged as a distinct driver of disease. Currently, limitations of cancer screening and surveillance methods often lead to identifying HNC in more advanced stages, with associated poor outcomes. Liquid biopsies, in particular circulating tumor DNA (ctDNA), offer the potential for enhancing screening, early diagnosis, and surveillance in HNC patients, with potential improvements in HNC patient outcomes. In this review, we examine current methodologies for detecting ctDNA and highlight current research illustrating viral and non-viral ctDNA biomarker utilities in HNC screening, diagnosis, treatment response, and prognosis. We also summarize current challenges and future directions for ctDNA testing in HNC patients.

Monitoring and adapting cancer treatment using circulating tumor DNA kinetics: Current research, opportunities, and challenges

Circulating tumor DNA (ctDNA) has emerged as a biomarker with wide-ranging applications in cancer management. While its role in guiding precision medicine in certain tumors via noninvasive detection of susceptibility and resistance alterations is now well established, recent evidence has pointed to more generalizable use in treatment monitoring. Quantitative changes in ctDNA levels over time (i.e., ctDNA kinetics) have shown potential as an early indicator of therapeutic efficacy and could enable treatment adaptation. However, ctDNA kinetics are complex and heterogeneous, affected by tumor biology, host physiology, and treatment factors. This review outlines the current preclinical and clinical knowledge of ctDNA kinetics in cancer and how early on-treatment changes in ctDNA levels could be applied in clinical research to collect evidence to support implementation in daily practice.

CDKN2B-AS1 promotes the proliferation, clone formation, and invasion of nasopharyngeal carcinoma cells by regulating miR-98-5p/E2F2 axis

OBJECTIVE

To explore the effect of CDKN2B antisense RNA 1 (CDKN2B-AS1) on the proliferation, clone formation, and invasion of nasopharyngeal carcinoma (NPC) cells by regulating miR-98-5p/E2F transcription factor 2 (E2F2) axis.

METHODS

The expressions of CDKN2B-AS1, miR-98-5p, and E2F2 in NPC tissues and cell lines (SUNE-1, 5-8F, 6-10B, and HK-1) as well as in peritumoral normal tissues and cell line NP69 were determined by qRT-PCR. Subcellular localization of CDKN2B-AS1 was detected using the fluorescence in situ hybridization assay. The targeting relationships between CDKN2B-AS1 and miR-98-5p as well as between miR-98-5p and E2F2 were analyzed by the dual-luciferase reporter assay and RNA binding protein immunoprecipitation assay. The proliferation, clone formation and invasion of 5-8F cells were measured using the CCK-8 assay, Clone formation assay, and transwell assay, respectively.

RESULTS

CDKN2B-AS1 was highly expressed in NPC tissues and cells, whereas the expression of miR-98-5p decreased in the NPC tissues and cells. Silencing of CDKN2B-AS1 inhibited the proliferation, clone formation, and invasion of NPC cells (all P<0.05). CDKN2B-AS1 acted asceRNA of miR-98-5p, and miR-98-5p inhibitor could partially reverse the inhibitory effect of silencing CDKN2B-AS1 on NPC cells (all P<0.05). CDKN2B-AS1 upregulated E2F2 by inhibiting miR-98-5p, and the upregulation of E2F2 partially reversed the inhibitory effect of miR-98-5p overexpression on the NPC cells (all P<0.05).

CONCLUSION

CDKN2B-AS1, as a lncRNA, can regulate E2F2 by sponging miR-98-5p to promote the proliferation, clone formation, and invasion of NPC cells.

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.

Dynamic Changes of Post-Radiotherapy Plasma Epstein-Barr Virus DNA in a Randomized Trial of Adjuvant Chemotherapy Versus Observation in Nasopharyngeal Cancer

PURPOSE

To study the dynamic changes in plasma Epstein-Barr virus (pEBV) DNA after radiotherapy in nasopharyngeal cancer (NPC).

EXPERIMENTAL DESIGN

We conducted a randomized controlled trial of adjuvant chemotherapy versus observation in patients with NPC who had detectable pEBV DNA at 6 weeks post-radiotherapy. Randomized patients had a second pEBV DNA checked at 6 months post-randomization. The primary endpoint was progression-free survival (PFS).

RESULTS

We prospectively enrolled 789 patients. Baseline post-radiotherapy pEBV DNA was undetectable in 573 (72.6%) patients, and detectable in 216 (27.4%) patients, of whom 104 (13.2%) patients were eligible for randomization to adjuvant chemotherapy (n = 52) versus observation (n = 52). The first post-radiotherapy pEBV DNA had a sensitivity of 0.48, specificity of 0.81, area under receiver-operator characteristics curve (AUC) of 0.65, false positive (FP) rate of 13.8%, and false negative (FN) rate of 14.4% for disease progression. The second post-radiotherapy pEBV DNA had improved sensitivity of 0.81, specificity of 0.75, AUC of 0.78, FP rate of 14.3%, and FN rate of 8.1%. Patients with complete clearance of post-radiotherapy pEBV DNA (51%) had survival superior to that of patients without post-radiotherapy pEBV DNA clearance (5-year PFS, 85.5% vs. 23.3%; HR, 9.6; P < 0.0001), comparable with patients with initially undetectable post-radiotherapy pEBV DNA (5-year PFS, 77.1%), irrespective of adjuvant chemotherapy or observation.

CONCLUSIONS

Patients with NPC with detectable post-radiotherapy pEBV DNA who experienced subsequent pEBV DNA clearance had superior survival comparable with patients with initially undetectable post-radiotherapy pEBV DNA. Post-radiotherapy pEBV DNA clearance may serve as an early surrogate endpoint for long-term survival in NPC.

The Most Efficacious Induction Chemotherapy Regimen for Locoregionally Advanced Nasopharyngeal Carcinoma: A Network Meta-Analysis

Background

Induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) for non-metastatic locoregionally advanced nasopharyngeal carcinoma (NPC) has gained considerable attention. However, the most efficacious IC regimens remain investigational. We aimed to compare the survival benefits of all available IC regimens followed by CCRT in this network meta-analysis.

Methods

All randomized-controlled trials of CCRT with or without IC in non-metastatic locoregionally advanced NPC were included, with an overall nine trials of 2,705 patients counted in the analysis. CCRT alone was the reference category. Eight IC regimens followed by CCRT were analyzed: docetaxel + cisplatin (DC), gemcitabine + carboplatin + paclitaxel (GCP), gemcitabine + cisplatin (GP), mitomycin + epirubicin + cisplatin + fluorouracil + leucovorin (MEPFL), cisplatin + epirubicin + paclitaxel (PET), cisplatin + fluorouracil (PF), cisplatin + capecitabine (PX) and cisplatin + fluorouracil (PF), cisplatin + capecitabine (PX). Fixed-effects frequentist network meta-analysis models was applied and P-score was used to rank the treatments.

Results

DC, GP, and PX were the top three IC regimens with the highest probability of benefit on overall survival (OS). Their corresponding hazard ratios (HRs) (95% CIs) compared with CCRT alone were of 0.24 (0.08–0.73), 0.43 (0.24–0.77), and 0.54 (0.27–1.09) and the respective P-scores were 94%, 82%, and 68%. The first three IC regimens showing significantly improved progression-free survival (PFS) were PX, followed by GP and DC with respective HRs of 0.46 (0.24–0.88), 0.51 (0.34–0.77), and 0.49 (0.20–1.20), and P-scores of 82%, 78%, and 74%. Among the studies in the intensity-modulated radiation therapy (IMRT) era, GP and PX were the best performed IC regimens, whilst DC performed the best among non-IMRT studies. Doublet and gemcitabine-based IC regimens had better survival benefits compared to triplet and taxane-based IC regimens, respectively.

Conclusions

Given its consistent superiority in both OS and PFS, DC, GP, and PX ranked among the three most efficacious IC regimens in both the overall and subgroup analysis of IMRT or non-IMRT studies. Exploratory analyses suggested that doublet and gemcitabine-based IC regimens showed better survival performance.

Comparison of efficacy and safety of three induction chemotherapy regimens with gemcitabine plus cisplatin (GP), cisplatin plus fluorouracil (PF) and cisplatin plus capecitabine (PX) for locoregionally advanced previously untreated nasopharyngeal carcinoma: A pooled analysis of two prospective studies

PURPOSE

We compared, in this pooled analysis, the differences in efficacy and safety between three induction chemotherapy regimens including gemcitabine plus cisplatin (GP), cisplatin plus fluorouracil (PF) and cisplatin plus capecitabine (PX) in patients recruited into our two prospective studies for previously untreated locoregionally advanced nasopharyngeal carcinoma (NPC).

METHODS

GP, PF or PX followed by radical concurrent chemoradiotherapy was given to patients with previously untreated locoregionally advanced (stage III to IVA) NPC prospectively recruited into our two prospective studies. The study endpoints included progression-free survival (PFS) and overall survival (OS), locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and major acute and late treatment-related toxicities (grade ≥ 3).

RESULTS

From 2006 to 2016, 278 patients were enrolled (84, 94 and 100 patients in GP, PF and PX group respectively). After a median follow-up of 80 months, the 3-year PFS, OS, LRFS, DMFS and CSS of the whole population were 78.7%, 88.1%, 84.9%, 80.9% and 89.8%, respectively. There were no significant differences in prespecified survival endpoints among GP, PF and PX in both stage III and stage IVA patients. GP had lower incidences of severe (grade ≥ 3) anemia and diarrhea in stage III patients, as well as severe anemia, dehydration, renal impairment and vomiting in stage IVA patients. The incidences of grade ≥ 3 late toxicities were similar among these 3 induction regimens.

CONCLUSION

GP had similar efficacy and potentially fewer treatment-related complications compared with PF and PX as induction chemotherapy for previously untreated locoregionally advanced NPC.