Involvement of both cervical lymph nodes and retropharyngeal lymph nodes has prognostic value for N1 patients with nasopharyngeal carcinoma

Optimal Size Threshold for MRI-Detected Retropharyngeal Lymph Nodes to Predict Outcomes in Nasopharyngeal Carcinoma: A Two-Center Study

BACKGROUND. Retropharyngeal lymph node (RLN) metastases have profound prognostic implications in patients with nasopharyngeal carcinoma (NPC). However, the AJCC staging system does not specify a size threshold for determining RLN involvement, resulting in inconsistent thresholds in practice. OBJECTIVE. The purpose of this article was to determine the optimal size threshold for determining the presence of metastatic RLNs on MRI in patients with NPC, in terms of outcome predictions. METHODS. This retrospective study included 1752 patients (median age, 46 years; 1297 men, 455 women) with NPC treated by intensity-modulated radiotherapy (RT) from January 2010 to March 2014 from two hospitals; 438 patients underwent MRI 3-4 months after treatment. Two radiologists measured the minimal axial diameter (MAD) of the largest RLN for each patient using a consensus process. A third radiologist measured MAD in 260 randomly selected patients to assess interobserver agreement. Initial ROC and restricted cubic spline (RCS) analyses were used to derive an optimal MAD threshold for predicting progression-free survival (PFS). The threshold's predictive utility was assessed in multivariable Cox regression analyses, controlling for standard clinical predictors. The threshold's utility for predicting PFS and overall survival (OS) was compared with a 5-mm threshold using Kaplan-Meier curves and log-rank tests. RESULTS. The intraclass correlation coefficient for MAD was 0.943. ROC and RCS analyses yielded an optimal threshold of 6 mm. In multivariable analyses, MAD of 6 mm and greater independently predicted PFS in all patients (HR = 1.35, p = .02), patients with N0 or N1 disease (HR = 1.80, p = .008), and patients who underwent posttreatment MRI (HR = 1.68, p = .04). In patients with N1 disease without cervical lymph node involvement, 5-year PFS was worse for MAD greater than or equal to 6 mm than for MAD that was greater than or equal to 5 mm but less than 6 mm (77.2% vs 89.7%, p = .03). OS was significantly different in patients with stage I and stage II disease defined using a 6-mm threshold (p = .04), but not using a 5-mm threshold (p = .09). The 5-year PFS rate was associated with a post-RT MAD of 6 mm and greater (HR = 1.68, p = .04) but not a post-RT MAD greater than or equal to 5 mm (HR = 1.09, p = .71). CONCLUSION. The findings support a threshold MAD of 6 mm for determining RLN involvement in patients with NPC. CLINICAL IMPACT. Future AJCC staging updates should consider incorporation of the 6-mm threshold for N-category and tumor-stage determinations.

Radiomic analysis of MRI for prediction of response to induction chemotherapy in nasopharyngeal carcinoma patients

AIM

To establish and validate radiomic models for response prediction to induction chemotherapy (IC) in nasopharyngeal carcinoma (NPC) using the radiomic features from pretreatment MRI.

MATERIALS AND METHODS

This retrospective analysis included 184 consecutive NPC patients, 132 in the primary cohort and 52 in the validation cohort. Radiomic features were derived from contrast-enhanced T1-weighted imaging (CE-T1) and T2-weighted imaging (T2-WI) for each subject. The radiomic features were then selected and combined with clinical characteristics to build radiomic models. The potential of the radiomic models was evaluated based on its discrimination and calibration. To measure the performance of these radiomic models in predicting the treatment response to IC in NPC, the area under the receiver operating characteristic curve (AUC), and sensitivity, specificity, and accuracy were used.

RESULTS

Four radiomic models were constructed in the present study including the radiomic signature of CE-T1, T2-WI, CE-T1 + T2-WI, and the radiomic nomogram of CE-T1. The radiomic signature of CE-T1 + T2-WI performed well in distinguishing response and non-response to IC in patients with NPC, which yielded an AUC of 0.940 (95% CI, 0.885-0.974), sensitivity of 83.1%, specificity of 91.8%, and accuracy of 87.1% in the primary cohort, and AUC of 0.952 (95% CI, 0.855-0.992), sensitivity of 74.2%, specificity of 95.2%, and accuracy of 82.7% in the validation cohort.

CONCLUSION

MRI-based radiomic models could be helpful for personalised risk stratification and treatment in NPC patients receiving IC.

Intra- and peritumoral MRI radiomics assisted in predicting radiochemotherapy response in metastatic cervical lymph nodes of nasopharyngeal cancer

BACKGROUND

To establish and validate radiomic models combining intratumoral (Intra) and peritumoral (Peri) features obtained from pretreatment MRI for the prediction of treatment response of lymph node metastasis from nasopharyngeal cancer (NPC).

METHODS

One hundred forty-five NPC patients (102 in the training and 43 in the validation set) were retrospectively enrolled. Radiomic features were extracted from Intra and Peri regions on the metastatic cervical lymph node, and selected with the least absolute shrinkage and selection operator (LASSO). Multivariate logistic regression analysis was applied to build radiomic models. Sensitivity, specificity, accuracy, and the area under the curve (AUC) of receiver operating characteristics were employed to evaluate the predictive power of each model.

RESULTS

The AUCs of the radiomic model of Intra, Peri, Intra + Peri, and Clinical-radiomic were 0.910, 0.887, 0.934, and 0.941, respectively, in the training set and 0.737, 0.794, 0.774, and 0.783, respectively, in the validation set. There were no significant differences in prediction performance among the radiomic models in the training and validation sets (all P > 0.05). The calibration curve of the radiomic model of Peri demonstrated good agreement between prediction and observation in the training and validation sets.

CONCLUSIONS

The pretreatment MRI-based radiomics model may be useful in predicting the treatment response of metastatic lymph nodes of NPC. Besides, the generalization ability of the radiomic model of Peri was better than that of Intra and Intra + Peri.

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.

Re-evaluation of the prognostic significance of retropharyngeal node metastasis in nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy

BACKGROUND AND PURPOSE

To investigate the prognostic value of retropharyngeal lymphadenopathy in nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy.

MATERIALS AND METHODS

Retrospective studies were performed in a total of 1197 patients. We evaluated the incidence of the retropharyngeal node (RPN) metastasis and the characteristics of the metastatic RPN including laterality, size, necrosis, and extranodal neoplastic spread.

RESULTS

RPN metastasis occured in 86.3% of patients. The RPN and level II metastasis shared similar survival outcomes. RPN metastasis was an independent prognostic factor for distant failure (hazard ratio = 1.615; 95% confidence interval, 1.063-2.452; P = 0.025), in which the laterality of RPN metastasis significantly influences both the distant failure (P = 0.006) and disease progression (P = 0.001). In N1 disease, the occurrence of unilateral and bilateral RPN metastasis resulted in significantly different outcomes of the disease-specific survival (P = 0.045) and progression-free survival (P = 0.049). The co-occurrence of bilateral RPN and cervical lymph nodes (CLN) metastasis was an independent adverse prognostic factor (P < 0.01) for distant failure and disease progression but not for locoregional recurrence.

CONCLUSION

Both the RPN and level II are the first stations of NPC lymph node metastasis. For N1-stage NPC patients, RPN metastasis, especially co-occurrence of bilateral RPN and CLN metastasis, have an adverse influence on survival outcomes.

Contemporary management of the neck in nasopharyngeal carcinoma

Up to 85% of the patients with nasopharyngeal carcinoma present with regional nodal metastasis. Although excellent nodal control is achieved with radiotherapy, a thorough understanding of the current TNM staging criteria and pattern of nodal spread is essential to optimize target delineation and minimize unnecessary irradiation to adjacent normal tissue. Selective nodal irradiation with sparing of the lower neck and submandibular region according to individual nodal risk is now emerging as the preferred treatment option. There has also been continual refinement in staging classification by incorporating relevant adverse nodal features. As for the uncommon occurrence of recurrent nodal metastasis after radiotherapy, surgery remains the standard of care.

Verification of the Efficacy of New Diagnostic Criteria for Retropharyngeal Nodes in a Cohort of Nasopharyngeal Carcinoma Patients

Purpose: A multistage approach to diagnose lateral retropharyngeal nodes (LRPNs) of nasopharyngeal carcinoma (NPC) had been proposed and warranted for validation. Methods: Between 2012 and 2017, the patients with newly diagnosed NPC were enrolled. The responsive nodes or those that progressed during follow-up were positive. The criteria for the multistage approach delimited LRPNs with a minimal axial diameter (MIAD) ≥ 6.1 mm were assessed as positive and if the mean standard uptake value ≥ 2.6, or if the maximal coronal diameter ≥ 25 mm and maximal axial diameter ≥ 8 mm with nodes MIAD < 6.1 mm were also considered as positive. The outcomes were compared with the MIAD cutoff value ≥ 6 mm (traditional method). A chi-squared test was used to compare two areas under the curve of the receiver operating characteristic curves. Results: A total of 67 eligible NPC cases and 155 LRPNs (72 positive and 83 negative) were analyzed. The accuracy, specificity, and sensitivity of the traditional method were 0.91, 0.93, and 0.89, respectively. The values for the multistage approach all reached 0.94. The area under the curve was significantly greater for the multistage approach compared with the traditional method (p = 0.023). Conclusion: The results support the advantage of the multistage approach.

Retrospective dose reconstruction of prostate stereotactic body radiotherapy using cone-beam CT and a log file during VMAT delivery with flattening-filter-free mode

This study aimed to reconstruct the dose distribution of single fraction of stereotactic body radiotherapy for patients with prostate cancer using cone-beam computed tomography (CBCT) and a log file during volumetric-modulated arc therapy (VMAT) delivery with flattening-filter-free (FFF) mode. Twenty patients with clinically localized prostate cancer were treated with FFF-VMAT, and projection images for in-treatment CBCT (iCBCT) imaging were concomitantly acquired with a log file. A D₉₅ dose of 36.25 Gy in five fractions was prescribed to each planning target volume (PTV) on each treatment planning CT (pCT). Deformed pCT (dCT) was obtained from the iCBCT using a hybrid deformable image registration algorithm. Dose distributions on the dCT were calculated using Pinnacle³ v9.10 by converting the log file data to Pinnacle³ data format using an in-house software. Dose warping was performed by referring to deformation vector fields calculated from pCT and dCT. Reconstructed dose distribution was compared with that of the original plan. Dose differences between the original and reconstructed dose distributions were within 3% at the isocenter and observed in PTV and organ-at-risk (OAR) regions. Differences in OAR regions were relatively larger than those in the PTV, presumably because OARs were more deformed than the PTV. Therefore, our method can be used successfully to reconstruct the dose distributions of one fraction using iCBCT and a log file during FFF-VMAT delivery.

Implication of viral microRNAs in the genesis and diagnosis of Epstein-Barr virus-associated tumors

The Epstein-Barr virus (EBV) is tightly associated with a variety of human tumors, including Burkitt lymphoma and acquired immune deficiency syndrome-related lymphoma of B-cell origin, as well as nasopharyngeal carcinoma and gastric cancer of epithelial origin. The virus latently infects the host cells and expresses proteins and non-coding RNAs to achieve malignancy. MicroRNAs (miRNAs or miRs) are small RNAs consisting of 19-25 nucleotides, which directly bind to the 3'-untranslated region of mRNAs to promote degradation and inhibit translation of mRNAs. EBV-encoded miRs are generated from two regions of the viral genome, within the apoptosis regulator BHRF1 gene locus and near the BamHI A region in a latency type-dependent manner. In addition, EBV-encoded miRs epigenetically regulate the expression of molecules that are effectors of the cell cycle progression, migration, apoptosis and innate immunity, serving a vital role in supporting viral replication and occurrence of EBV-associated tumors. The feasibility of using such miRs as biomarkers for the diagnosis and prognosis of EBV-associated tumors is currently under investigation.

[Development and validation of a multivariate risk model for distant metastasis of advanced nasopharyngeal carcinoma]

OBJECTIVE

To develop a model based on the clinical variables for evaluating the risk of distant metastasis in patients with advanced nasopharyngeal carcinoma (NPC).

METHODS

From September,2007 to June,2015,a total of 238 consecutive patients with biopsy-proven NPC in stage Ⅲ-Ⅳ(M0) based on the AJCC TNM staging manual were enrolled in this study,including 106 male and 34 female patients with a median age of 45 years (range 18-68 years).In this cohort,126 patients received concurrent chemoradiotherapy,and 24 received chemotherapy and radiotherapy,and 40 had induction chemotherapy.We used the least absolute shrinkage and selection operator (LASSO) method to select the most significant features for establishing the model for assessing the risks of distant metastasis.

RESULTS

Among the 18 clinical variables tested,5 were significantly associated with distant metastasis in advanced NPC,including plasma Epstein-Barr virus (EBV) DNA,neutrophil/lymphocytes (NLR),VCA-IgA,concurrent chemoradiotherapy,and induction chemotherapy.Based on these 5 clinical variables,we established the following model:risk score=1.73×EBV DNA+0.54×NLR+0.38×VCA-IgA-0.95×concurrent chemoradiotherapy-2.37×induction chemotherapy+0.51.The cutoff point of this model was-0.62,which classified the patients into high-risk and low-risk groups for distant metastasis.This model showed a good performance in predicting distant metastasis in patients with advanced NPC (P<0.01).

CONCLUSIONS

The model we established herein can be used for evaluating the risks of distant metastasis in patients with advanced NPC and provides assistance in the clinical decision-making on individualized treatment strategy.

The efficacy of induction chemotherapy in the treatment of stage II nasopharyngeal carcinoma in intensity modulated radiotherapy era

PURPOSE

To evaluate the efficacy of induction chemotherapy in the treatment of stage II nasopharyngeal carcinoma (NPC) in era of intensity modulated radiotherapy (IMRT).

METHODS AND MATERIALS

A total of 173 patients with American Joint Committee on Cancer (AJCC) 7th stage II NPC from two institutions were included. All patients were divided into two groups: induction chemotherapy + concurrent chemoradiotherapy group (ICRT) group and concurrent chemoradiotherapy group (CCRT). Induction chemotherapy was consisted of one to three cycles of cisplatin plus fluorouracil (PF) or paclitaxel plus cisplatin (TP). Concurrent chemotherapy included one to three cycles of cisplatin. We retrospectively assessed overall survival (OS), progression-free survival (PFS), locoregional failure free survival (LRFFS) and distant metastasis free survival (DMFS) in patients of both groups. T-test, Chi-square test, Kaplan-Meier methodology and Cox proportional hazards model were used to analyze.

RESULTS

With a median follow up of 64.7 months, no significant difference was found in grade 3-4 hematologic toxicity, liver dysfunction and renal impairment between ICRT and CCRT group. Univariable analyses shown adding induction chemotherapy to CCRT significantly decreased 5-year OS (87.9% vs 95.5%, P = 0.033), 5-year PFS (74.0% vs 86.1%, P = 0.035), 5-year LRFFS (80.0% vs 91.2%, P = 0.016), but there was no statistically significant difference in 5-year DMFS (87.1% vs 94.7%, P = 0.095). In multivariable analyses, we found the consistent results that induction chemotherapy was a negative factor associated with OS (HR of death = 3.768, 95% CI = 1.117-12.709; P = 0.032), PFS (HR of progression = 2.156, 95% CI = 1.060-4.386; P = 0.034), LRFFS (HR of locoregional relapse = 2.435, 95% CI = 1.009-5.874; P = 0.048) and also DMFS (HR of metastasis = 2.873, 95% CI = 1.005-8.211; P = 0.049), in stage II NPC patients.

CONCLUSION

In present study, we found that induction chemotherapy caused deleterious effect on stage II NPC patients. However, this is a retrospective study and the adverse effects of induction chemotherapy has not been previously reported. It warrants further investigation.

Cervical nodal necrosis is an independent survival predictor in nasopharyngeal carcinoma: an observational cohort study

PURPOSE

Most nasopharyngeal carcinoma (NPC) patients present with locoregionally advanced disease at the time of diagnosis; however, there is a lack of consensus on specific prognostic factors potentially improving overall survival, especially in late-stage disease. Herein, we conducted a retrospective study to evaluate various potential prognostic factors in order to provide useful information for clinical treatment of T3/T4-stage NPC.

PATIENTS AND METHODS

A total of 189 previously untreated NPC patients were enrolled in the current study. All patients received intensity-modulated radiotherapy. Survival, death, relapse-free survival (both local and regional), and metastasis were recorded during follow-up. Factors affecting patient survival were assessed by using univariate and multivariate analyses.

RESULTS

The median follow-up time was 69 months. The 5-year local-regional recurrence-free survival, distant metastasis-free survival, progression-free survival (PFS), and overall survival (OS) of the entire group were 89.8%, 71.5%, 66.3%, and 68.9%, respectively. Univariate analysis revealed significant differences in the 5-year PFS (58.5% vs 72.5%, P=0.015) and OS (59.5% vs 75.8%, P=0.033) rates of patients with and without cervical nodal necrosis (CNN). Subgroup analyses revealed that CNN was associated with poorer distant metastasis-free survival and PFS among patients with N2 stage (P=0.046 and P=0.005) and with poorer PFS among patients with T3 or III stage (all P=0.022). Multivariate analysis revealed CNN to be an independent prognostic factor for PFS and OS (PFS: adjusted hazard ratio, 1.860; 95% CI: 1.134-3.051; P=0.014; OS: adjusted hazard ratio, 1.754; 95% CI: 1.061-2.899; P=0.028).

CONCLUSION

CNN is a potential independent negative prognostic factor in NPC patients. Our results suggest that stratification of NPC patients based on their CNN status should be considered as part of NPC disease management.

Thyroid adenoma and nasopharyngeal carcinoma with metastasis to cervical lymph nodes is misdiagnosed and treated for thyroid carcinoma: A case report

Lymph node metastasis of nasopharyngeal carcinoma follows an orderly pattern, and diagnosis of nasopharyngeal carcinoma is often made by lymph node biopsy. In the present study, following neck palpation, ultrasonography and cervical computer tomography, a 52-year-old female patient with thyroid adenoma and enlarged cervical lymph nodes was misdiagnosed as thyroid carcinoma without undergoing preoperative biopsy, followed by unnecessary total thyroidectomy. Systematic CT scan and nasal endoscopic biopsy confirmed the correct diagnosis of primary NPC concurrent with thyroid adenoma. The patient received palliative radiotherapy and L-thyroxine substitution therapy, and was followed up closely via internet-based approaches with life-style intervention, medication consultation and psychological support for improvement of life quality after radiotherapy. In conclusion, primary malignancies with thyroid metastasis must be considered in the differential diagnosis of thyroid tumors with enlarged cervical lymph nodes.

Overexpression of acylglycerol kinase is associated with poorer prognosis and lymph node metastasis in nasopharyngeal carcinoma

Acylglycerol kinase (AGK) has been reported to promote a malignant phenotype and enhance the development of cancer stem cells. However, the clinical value of AGK in cancer remains unclear. This study aimed to investigate the expression and clinicopathological significance of AGK in nasopharyngeal carcinoma (NPC). AGK was significantly upregulated in NPC cell lines and clinical specimens as indicated by real-time PCR and Western blotting. Among the AGK-positive cases, 52/114 (45.6 %) of the archived human NPC specimens expressed high levels of AGK. High expression of AGK was associated with significantly shorter overall and disease-free survival (P < 0.001 and P = 0.002; log-rank test) and was an independent prognostic factor for overall survival (P = 0.041; multivariate Cox analysis). High AGK expression was associated with lymph node metastasis (P < 0.001; chi-squared test) and was an independent predicted factor for lymph node metastasis in NPC (P = 0.032; multivariate logistic analysis). AGK is overexpressed and associated with disease progression and lymph node metastasis in NPC. AGK has potential as a novel prognostic factor for overall survival in NPC.

Subdivision of M category for nasopharyngeal carcinoma with synchronous metastasis: time to expand the M categorization system

INTRODUCTION

The current metastatic category (M) of nasopharyngeal carcinoma (NPC) is a "catch-all" classification, covering a heterogeneous group of tumors ranging from potentially curable to incurable. The aim of this study was to design an M categorization system that could be applied in planning the treatment of NPC with synchronous metastasis.

METHODS

A total of 505 NPC patients diagnosed with synchronous metastasis at Sun Yat-sen University Cancer Center between 2000 and 2009 were involved. The associations of clinical variables, metastatic features, and a proposed M categorization system with overall survival (OS) were determined by using Cox regression model.

RESULTS

Multivariate analysis showed that Union for International Cancer Control (UICC) N category (N1-3/N0), number of metastatic lesions (multiple/single), liver involvement (yes/no), radiotherapy to primary tumor (yes/no), and cycles of chemotherapy (>4/≤4) were independent prognostic factors for OS. We defined the following subcategories based on liver involvement and the number of metastatic lesions: M1a, single lesion confined to an isolated organ or location except the liver; M1b, single lesion in the liver and/or multiple lesions in any organs or locations except the liver; and M1c, multiple lesions in the liver. Of the 505 cases, 74 (14.7%) were classified as M1a, 296 (58.6%) as M1b, 134 (26.5%) as M1c, and 1 was not specified. The three M1 subcategories showed significant difference in OS [M1b vs. M1a, hazard ratio (HR) = 1.69, 95% confidence interval (CI) = 1.16-2.48, P = 0.007; M1c vs. M1a, HR = 2.64, 95% CI = 1.75-3.98, P < 0.001].

CONCLUSIONS

We developed an M categorization system based on the independent factors related to the prognosis of patients with metastatic NPC. This system may be helpful to further optimize individualized care for NPC patients.

M1 stage subdivision and treatment outcome of patients with bone-only metastasis of nasopharyngeal carcinoma

BACKGROUND

The current M1 stage in nasopharyngeal carcinoma (NPC) does not differentiate patients based on metastatic site and number of metastases. This study aims to subdivide the M1 stage of NPC patients with bone-only metastases and to identify the patients who may benefit from combined chemoradiotherapy (CRT).

METHODS

Between 1998 and 2007, 312 patients diagnosed with bone-only metastasis at Sun Yat-sen University Cancer Center were enrolled. Various possible subdivisions of M1 stage were considered, including by the time order of metastasis (synchronous vs. metachronous), involvement of specific bone metastatic site, the number of metastatic sites, and the number of metastases. The correlation of the subdivisions of M1 stage with overall survival (OS) was determined by Cox regression.

RESULTS

The median OS was 23.4 months. Patients with more than three metastatic sites had significantly poorer OS than patients with three or fewer metastatic sites (16.2 vs. 32.4 months; p < .001). Metastasis to the spine was significantly associated with unfavorable OS (20.4 vs. 37.9 months; p < .001). Multivariate analysis showed that number of metastatic sites (more than three vs. three or fewer), spine involvement (present vs. absent), and treatment modality (CRT vs. chemotherapy or radiotherapy only) were independent prognostic factors for OS. In stratified analysis, compared with chemotherapy or radiotherapy alone, combined chemoradiotherapy could significantly benefit the patients with single bone metastasis (hazard ratio: 0.21; 95% confidence interval: 0.09-0.50).

CONCLUSION

Metastasis to the spine and having more than three bone metastatic sites are independent unfavorable predictors for OS in NPC patients with bone-only metastasis. Combined chemoradiotherapy should be considered for patients with single bone metastasis.