Optimal plasma pretreatment EBV DNA cut-off point for nasopharyngeal cancer patients treated with intensity modulated radiation therapy

Multimodality radiomics for tumor prognosis in nasopharyngeal carcinoma

BACKGROUND

The prognosis of nasopharyngeal carcinoma (NPC) is challenging due to late-stage identification and frequently undetectable Epstein-Barr virus (EBV) DNA. Incorporating radiomic features, which quantify tumor characteristics from imaging, may enhance prognosis assessment.

PURPOSE

To investigate the predictive power of radiomic features on overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) in NPC.

MATERIALS AND METHODS

A retrospective analysis of 183 NPC patients treated with chemoradiotherapy from 2010 to 2019 was conducted. All patients were followed for at least three years. The pretreatment CT images with contrast medium, MR images (T1W and T2W), as well as gross tumor volume (GTV) contours, were used to extract radiomic features using PyRadiomics v.2.0. Robust and efficient radiomic features were chosen using the intraclass correlation test and univariate Cox proportional hazard regression analysis. They were then combined with clinical data including age, gender, tumor stage, and EBV DNA level for prognostic evaluation using Cox proportional hazard regression models with recursive feature elimination (RFE) and were optimized using 20 repetitions of a five-fold cross-validation scheme.

RESULTS

Integrating radiomics with clinical data significantly enhanced the predictive power, yielding a C-index of 0.788 ± 0.066 to 0.848 ± 0.079 for the combined model versus 0.745 ± 0.082 to 0.766 ± 0.083 for clinical data alone (p<0.05). Multimodality radiomics combined with clinical data offered the highest performance. Despite the absence of EBV DNA, radiomics integration significantly improved survival predictions (C-index ranging from 0.770 ± 0.070 to 0.831 ± 0.083 in combined model versus 0.727 ± 0.084 to 0.734 ± 0.088 in clinical model, p<0.05).

CONCLUSIONS

The combination of multimodality radiomic features from CT and MR images could offer superior predictive performance for OS, PFS, and DMFS compared to relying on conventional clinical data alone.

Comparison of Real-Time PCR and Digital PCR for Detection of Plasma Epstein-Barr Virus DNA in Nasopharyngeal Carcinoma

Plasma Epstein-Barr virus (EBV) DNA is an established biomarker for endemic nasopharyngeal carcinoma. However, existing real-time quantitative PCR (qPCR) assays are limited by poor interlaboratory reproducibility. This is a barrier to biomarker integration into staging systems and management. It was hypothesized that EBV digital PCR (dPCR) would have similar sensitivity but improved precision relative to qPCR. Using the World Health Organization EBV standard and patient specimens, the NRG-HN001 BamHI-W qPCR, two commercial EBNA-1 qPCR assays, and two laboratory-developed dPCR assays amplifying the BamHI-W, EBNA-1, and EBER targets were compared. Testing was conducted in the North American reference laboratory for the NRG-HN001 randomized trial. The EBV dPCR assays achieved similar performance compared with qPCR. Although dPCR does not require quantitation standards, different dPCR thresholding algorithms yielded significant qualitative and quantitative variation. This was most evident with low levels of EBV DNA. No-template control-informed thresholding (ddpcRquant) mitigated false-positive/false-negative findings. The NRG-HN001 BamHI-W qPCR and laboratory-developed BamHI-W droplet dPCR offered higher sensitivity, lower limit of blank, higher precision at low plasma EBV DNA levels (≤1500 IU/mL), and higher overall agreement with clinical specimens versus single-copy qPCR/dPCR targets (EBNA-1/EBER). These data confirm the rationale for using the BamHI-W target to define prognostic thresholds and indicate that both qPCR and dPCR methods harmonized to the World Health Organization standard can provide the necessary analytical performance.

Impact of primary site on survival in patients with nasopharyngeal carcinoma from 2004 to 2015

Background

Nasopharynx carcinoma (NPC) is the most common malignant tumor of the nasopharynx. Many studies have shown some factors related with the prognosis of NPC patients. Our study aims to evaluate the differences of prognosis between initial and second primary NPC.

Material and methods

The Surveillance, Epidemiology, and End Results (SEER) program was used to perform the population-based analysis in NPC patients who were newly diagnosed between 2004 and 2015. Kaplan-Meier and Cox regressions were used to evaluate the effects of primary site on the overall survival (OS), as well as the cancer-specific survival (CSS).

Results

Our study included 5,012 NPC patients: 4,474 initial primary NPC patients and 5,38 s primary NPC patients. Significant differences were observed in sex, age at diagnosis, race, median household income, histological type, American Joint Committee on Cancer (AJCC) stage, N-stage, radiation treatment and chemotherapy between patients with initial and second NPC (P < 0.05). Moreover, the patients with second NPC had longer survival months. In addition, radiation and chemotherapy were recommended both in first and second primary NPC patients.

Conclusion

Worse prognosis was observed in patients with second primary NPC compared with those with primary NPC in all subgroups of AJCC stage and age at diagnosis.

Value of Diffusion-Weighted Imaging and Dynamic Contrast-Enhanced Magnetic Resonance Imaging for Prediction of Treatment Outcomes in Nasopharyngeal Carcinoma

OBJECTIVE

Magnetic resonance imaging (MRI) parameters that reflect the tumor microenvironment of nasopharyngeal carcinoma (NPC) may predict treatment response and facilitate treatment planning. This study aimed to evaluate the diffusion-weighted imaging and dynamic contrast-enhanced MRI (DCE-MRI) values for predicting the treatment outcomes in NPC patients.

METHODS

Eighty-three patients with NPC underwent pretreatment MRI simulation with diffusion-weighted imaging and dynamic contrast-enhanced MRI. Average values of the apparent diffusion coefficient (ADC), Ktrans, Kep, Ve, Vp, and tumor volume of the primary tumors were measured. Other potential clinical characteristics (age, sex, staging, pathology, pretreatment Epstein-Barr virus level, and treatment type) were analyzed. Patients underwent follow-up imaging 6 months after treatment initiation. Treatment responses were assigned according to the Response Evaluation Criteria in Solid Tumors guideline (version 1.1).

RESULTS

Fifty-one patients showed complete response (CR), whereas 32 patients did not (non-CR). Univariable logistic regression with variables dichotomized by optimal cutoff values showed that ADC ≥1.45 × 10-3 mm2/s, Vp ≥0.14, tumor volume of ≥14.05 mL, high stage (stages III and IV), and Epstein-Barr virus level of ≥2300 copies/mL were predictors of non-CR (P = 0.008, 0.05, 0.01, 0.009, and 0.04, respectively). The final multivariable model, consisting of a combination of ADC ≥1.45 × 10-3 mm2/s, Vp ≥0.14, and high stage, could predict non-CR with a good discrimination ability (area under the receiver operating characteristic curve, 0.76 [95% confidence interval, 0.66-0.87]; sensitivity, 62.50%; specificity, 80.39%; and accuracy 73.49%).

CONCLUSIONS

A multivariable prediction model using a combination of ADC ≥1.45 × 10-3 mm2/s, Vp ≥0.14, and high stage can be effective for treatment response prediction in NPC patients.

Tumor Prognostic Prediction of Nasopharyngeal Carcinoma Using CT-Based Radiomics in Non-Chinese Patients

Purpose

We aimed to construct predictive models for the overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) for nasopharyngeal carcinoma (NPC) patients by using CT-based radiomics.

Materials and Methods

We collected data from 197 NPC patients. For each patient, radiomic features were extracted from the CT image acquired at pretreatment via PyRadiomics. Feature selection was performed in two steps. First, features with high inter-observer variability based on multiple tumor delineations were excluded. Then, stratified bootstrappings were performed to identify feature combinations that most frequently achieved the highest (i) area under the receiver operating characteristic curve (AUC) for predicting 3-year OS, PFS, and DMFS or (ii) Harrell’s C-index for predicting time to event. Finally, regularized logistic regression and Cox proportional hazard models with the most frequently selected feature combinations as input were tuned using cross-validation. Additionally, we examined the robustness of the constructed model to variation in tumor delineation by simulating 100 realizations of radiomic feature values to mimic features extracted from different tumor boundaries.

Results

The combined model that used both radiomics and clinical features yielded significantly higher AUC and Harrell’s C-index than models using either feature set alone for all outcomes (p &lt; 0.05). The AUCs and Harrell’s C-indices of the clinical-only and radiomics-only models ranged from 0.758 ± 0.091 to 0.789 ± 0.082 and from 0.747 ± 0.062 to 0.767 ± 0.074, respectively. In comparison, the combined models achieved AUC of 0.801 ± 0.075 to 0.813 ± 0.078 and Harrell’s C-indices of 0.779 ± 0.066 to 0.796 ± 0.069. The results showed that our models were robust to variation in tumor delineation with the coefficient of variation ranging from 4.8% to 6.4% and from 6.7% to 9.3% for AUC and Harrell’s C-index, respectively.

Conclusion

Our results demonstrated that using CT-based radiomic features together with clinical features provided superior NPC prognostic prediction than using either clinical or radiomic features alone.

Combined Association of Tumoral PD-L1 Expression and Pretreatment Presence of Epstein-Barr Virus DNA With Risk Stratification and Prognosis of Patients With Nasopharyngeal Carcinoma

Background

Little is known about whether the combination of tumor programmed death-ligand 1 (PD-L1) expression and pretreatment EBV DNA status can help stratify nasopharyngeal carcinoma (NPC) patients by risk of metastasis or predict prognosis.

Methods

PD-L1 expression was assessed using immunohistochemical staining of 78 non-keratinizing NPC patients with clinical data. Survival outcomes and independent prognostic factors were identified.

Results

Seventy-eight patients were included, high PD-L1 expression was observed in 25 of 43 patients (58%) with metastasis, while it was observed only in 7 of 35 patients (20%) without metastasis. Multivariate analyses showed that progression-free survival (PFS) was independently predicted by tumoral PD-L1 expression and pretreatment EBV DNA status. When combining, 93.75% patients with high PD-L1 and EBV infection developed distant metastasis, and those patients were associated with worse PFS.

Conclusions

Both PD-L1 expression and pretreatment EBV DNA are closely related to metastasis and prognosis of NPC patients. Their combination can facilitate risk stratification and prognosis prediction, which may improve disease treatment and management.

Utility of diffusion-weighted magnetic resonance imaging in predicting the treatment response of nasopharyngeal carcinoma

OBJECTIVE

Predicting the treatment response in patients with nasopharyngeal carcinoma (NPC) is challenging. This study evaluated the utility of diffusion-weighted imaging (DWI) in predicting the treatment response in patients with NPC.

METHODS

We prospectively enrolled 33 patients with newly diagnosed NPC who underwent magnetic resonance imaging with the propeller DWI and apparent diffusion coefficient (ADC) map before and at 5 weeks after chemoradiation. The following ADC values of the primary tumor were calculated: pre-treatment ADC (pre-ADC), pre-treatment ADC ratio (pre-ADC ratio), ADC change (▵ADC), ADC change ratio (▵ADC ratio), and percentage of ADC change (▵%ADC). The correlations between these parameters and treatment outcomes were explored, and the patients were classified as good responders (complete response) and poor responders (stable disease, partial response, or progressive disease) based on the Response Evaluation Criteria in Solid Tumors, version 1.1.

RESULTS

The ▵ADC, ▵ADC ratio, and ▵%ADC were significantly lower in the poor-responder group (n = 12) than in the good-responder group (n = 21; p = 0.001, p = 0.002, and p = 0.004, respectively). There was no significant difference between groups in the pre-ADC and pre-ADC ratios (p = 0.602 and p = 0.685, respectively). The optimal ▵ADC, ▵ADC ratio, and ▵%ADC cutoff values for predicting poor response were >0.65 mm²/sec, 0.28, and 60%, respectively (sensitivity: 83.3%, 75%, and 83.3%; specificity: 71.4%, 85.7%, and 71.4%, respectively).

CONCLUSION

The ▵ADC, ▵ADC ratio, and ▵%ADC obtained during the pre-treatment and mid-treatment periods could be potential biomarkers for predicting treatment response in patients with NPC.

Disparity analysis and prognostic value of pretreatment whole blood Epstein-Barr virus DNA load and Epstein-Barr encoding region status in lymphomas: A retrospective multicenter study in Huaihai Lymphoma Working Group

Elevated Epstein-Barr virus (EBV) DNA load is common in lymphomas. However, it remains unclear whether the disparity in viral load and its prognostic value in lymphomas are correlated with Epstein-Barr encoding region (EBER) status. In this retrospective multicenter study, we collected the data of pretreatment whole blood EBV DNA (pre-EBV DNA) and EBER status and evaluated their disparity and prognostic values in lymphomas. A total of 454 lymphoma patients from December 2014 to August 2020 were retrospectively retrieved. Mann-Whitney U test, Kruskal-Wallis test and Bonferroni's adjustment were used to explore the disparity of EBV DNA and EBER status in lymphomas. Time-dependent receiver operating characteristic analysis and MaxStat analysis were used to determine optimal cutoff points of pre-EBV DNA load. Univariable and multivariable Cox proportional hazards models were established for the estimation of prognostic factors. The positive rate of EBV DNA in natural killer T-cell lymphoma (NKTL) patients was higher than that in diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and Hodgkin lymphoma (HL) patients, and the median positive pre-EBV copy number of NKTL was also higher than that of FL and DLBCL. EBV DNA could clearly distinguish the prognosis of DLBCL, NKTL, HL and peripheral T-cell lymphoma, and the integration of EBER status and EBV DNA could differentiate the prognosis of HL patients. Multivariable results revealed that pre-EBV DNA load had an effect on the prognosis of NKTL, FL and DLBCL. The status of pre-EBV DNA and EBER were disparate. Whole blood pre-EBV DNA predicted the prognosis of lymphomas, and the combination of EBV and EBER status could differentiate the prognosis of HL.

Value of dynamic contrast-enhanced magnetic resonance imaging for determining the plasma Epstein-Barr virus status and staging of nasopharyngeal carcinoma

AIM

To determine the associations between dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters and plasma Epstein-Barr virus (EBV) DNA status and nasopharyngeal carcinoma (NPC) stages.

METHODS

We prospectively studied the DCE-MRI results of 47 patients with newly diagnosed NPC and their pre-treatment plasma EBV DNA levels. We recruited all patients who had undergone MRI (1.5 T) simulation at the radiation therapy department of our institute between January 2018-2019. Regions of interest were drawn at primary tumors, and DCE-MRI parameters, including mean values of Ktrans, Kep, Ve, and Vp, were recorded. Spearman's rank correlation was used to identify significant associations between the DCE-MRI parameters and the plasma EBV DNA level and NPC stages. Mann-Whitney U tests and unpaired t-test were performed to compare the DCE-MRI parameters among different groups and to identify optimal cut-off values using receiver operating characteristic curves.

RESULTS

We found that the DCE-MRI parameters correlated with the plasma EBV DNA levels and NPC stages. Positive plasma EBV DNA was correlated with lower Kep (optimal cut-off value, 2.1 min^-1; area under the curve [AUC], 0.714) and higher Ve (optimal cut-off value, 0.675; AUC, 0.706). Ve higher than 0.765 (AUC, 0.678) was correlated with plasma EBV DNA (≥2300 copies mL^-1). Higher Ktrans (cut-off value, 1.495 min^-1) was correlated with high-T stage (AUC, 0.767) and high-stage group (AUC, 0.711).

CONCLUSIONS

The DCE-MRI parameters are correlated with the plasma EBV DNA status and NPC stages. Therefore, DCE-MRI findings may be used as imaging biomarkers for patients with NPC.

Circulating tumor cells: a valuable marker of poor prognosis for advanced nasopharyngeal carcinoma

Purpose

To evaluate the prognostic value of circulating tumor cells (CTCs) in nasopharyngeal carcinoma (NPC).

Methods

Cox’s proportional hazards regression models were used to identify whether CTCs was a poor prognostic factor for NPC. Chi-square tests were used to analyze and compare the distribution characteristics of CTCs in NPC. ROC curve was used to estimate the cut-off point of CTCs. Kaplan-Meier survival analyses were used to observe the prognostic value of CTCs alone and in combined with Epstein-Barr Virus DNA (EBV-DNA).

Results

CTCs was confirmed to be an independent risk factor for poor prognosis of NPC by Cox’s regression models that enrolled 370 NPC cases and took age, gender, EBV-DNA and CTCs as variables. The proportion of CTCs in stage IV NPC was statistically different from that in stage III; the cut-off point of CTCs between stage IV (288 cases) and stage III (70 cases) NPC estimated by ROC curve was 0.5. The prognosis of advanced NPC patients became worse with the increase of CTCs count. The combined detection of CTCs and EBV-DNA could better predict the prognosis of NPC compared with the single detection of EBV-DNA.

Prognostic value of Epstein-Barr virus DNA level for nasopharyngeal carcinoma: a meta-analysis of 8128 cases

BACKGROUND

Plasma levels of Epstein-Barr virus (EBV) DNA have been employed to predict survival outcomes of patients with nasopharyngeal carcinoma (NPC). However, the prognostic value of subsequent EBV DNA levels (mid or post treatment) for NPC is needed to identify by a large cohort of patients. We performed a meta-analysis of studies including data from 8128 patients to evaluate the prognostic value of EBV DNA in NPC patients.

METHODS

We searched PubMed, Web of Science, and the Cochrane library for prospective and retrospective studies. Hazard ratios (HRs) and confidence intervals (CIs) were extracted from the studies or calculated and pooled to assess the association between EBV DNA levels pre-treatment (pre-DNA), mid-treatment (mid-DNA), and post-treatment (post-DNA) on clinical outcomes.

RESULTS

A total of 22 studies with 8128 patients was included for analysis. Pre-DNA levels predicted overall survival, progression-free survival, distant metastasis-free survival, and local-regional failure survival with HRs (95% CIs) of 2.70 (2.06, 3.54), 2.70 (2.12, 3.44), 3.49 (2.35, 5.17), and 2.00 (1.45, 2.76), respectively, and the corresponding HRs for post-DNA levels were 4.86 (3.30, 7.17), 6.29 (3.41, 11.60), 5.68 (2.71,11.93), respectively. Mid-DNA levels predicted overall survival and progression-free survival with an HR (95% CI) of 3.02 (1.54, 5.29) and 3.15 (2.05, 4.83). Subgroup analysis showed that the HR of post-DNA wasn't influenced by different detection time of post-DNA (P = 0.22, I² = 33.2%).

CONCLUSION

The EBV DNA levels have a significant prognostic impact in patients with NPC. The effect of post-treatment EBV DNA level dominated that of pre-DNA and mid-DNA levels.

Comparison between the seventh and eighth edition of the AJCC/UICC staging system for nasopharyngeal cancer integrated with pretreatment plasma Epstein–Barr virus DNA level in a non-Chinese population: secondary analysis from a prospective randomized trial

The eighth AJCC/UICC staging for nasopharyngeal cancer had higher prognostic values than the previous edition. Pretreatment plasma EBV DNA integrated into the next edition could further improve the outcome prediction.