Liquid biopsy posttreatment surveillance in endemic nasopharyngeal carcinoma: a cost-effective strategy to integrate circulating cell-free Epstein-Barr virus DNA.

BACKGROUND: The optimal posttreatment surveillance strategy for nasopharyngeal carcinoma (NPC) remains unclear. Circulating cell-free Epstein-Barr virus (cfEBV) DNA has been recognized as a promising biomarker to facilitate early detection of NPC recurrence. Therefore, we aim to determine whether integrating circulating cfEBV DNA into NPC follow-up is cost-effective. METHODS: For each stage of asymptomatic nonmetastatic NPC patients after complete remission to primary NPC treatment, we developed a Markov model to compare the cost-effectiveness of the following surveillance strategies: routine follow-up strategy, i.e., (1) routine clinical physical examination; routine imaging strategies, including (2) routine magnetic resonance imaging plus computed tomography plus bone scintigraphy (MRI + CT + BS); and (3) routine 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT); cfEBV DNA-guided imaging strategies, including (4) cfEBV DNA-guided MRI + CT + BS and (5) cfEBV DNA-guided PET/CT. Clinical probabilities, utilities, and costs were derived from published studies or databases. Sensitivity analyses were performed. RESULTS: For all disease stages, cfEBV DNA-guided imaging strategies demonstrated similar survival benefits but were considerably more economical than routine imaging strategies. They only required approximately one quarter of the number of imaging studies compared with routine imaging strategies to detect one recurrence. Specifically, cfEBV DNA-guided MRI + CT + BS was most cost-effective for stage II (incremental cost-effectiveness ratio [ICER] $57,308/quality-adjusted life-year [QALY]) and stage III ($46,860/QALY) patients, while cfEBV DNA-guided PET/CT was most cost-effective for stage IV patients ($62,269/QALY). However, routine follow-up was adequate for stage I patients due to their low recurrence risk. CONCLUSIONS: The cfEBV DNA-guided imaging strategies are effective and cost-effective follow-up methods in NPC. These liquid biopsy-based strategies offer evidence-based, stage-specific surveillance modalities for clinicians and reduce disease burden for patients.

Prognostic potential of liquid biopsy tracking in the posttreatment surveillance of patients with nonmetastatic nasopharyngeal carcinoma.

BACKGROUND: The current study was performed to investigate whether circulating cell-free Epstein-Barr virus DNA (cfEBV DNA) would be useful for posttreatment surveillance in patients with nasopharyngeal carcinoma (NPC). METHODS: The authors identified a total of 1984 nondisseminated NPC patients from an institutional big-data research platform. Blood samples were collected within 3 months of the completion of radiotherapy and every 3 to 12 months thereafter for cfEBV DNA analysis. Patients were followed until disease recurrence was detected or for a median of 60 months. Diagnostic performance was assessed by calculating the sensitivity, specificity, and accuracy based on the clinical detection of disease recurrence by conventional surveillance modalities (imaging scans and pathological examination). RESULTS: During follow-up, a total of 767 patients (38.7%) had detectable cfEBV DNA. The recurrence rate among these patients was 63.8% (489 of 767 patients), which was significantly higher than that in patients with undetectable cfEBV DNA (8.6%; 105 of 1217 patients). cfEBV DNA sensitivity, specificity, and accuracy were 68.8%, 80.0%, and 78.2%, respectively, for local recurrence; 80.2%, 80.0%, and 85.9%, respectively, for regional recurrence; and 91.1%, 80.0%, and 92.8%, respectively, for distant metastasis. cfEBV DNA was found to have higher sensitivity for the detection of extrapulmonary metastases (94.9%-96.5%) compared with pulmonary metastases (78.4%). It is interesting to note that among the patients with disease recurrence with detectable cfEBV DNA, positive cfEBV DNA results preceded radiological and/or clinical evidence of disease recurrence by a median of 2.3 months (interquartile range, 0.1-9.5 months). In addition, of the 278 cfEBV DNA-positive patients who did not develop disease recurrence, 227 (81.7%) had transiently positive cfEBV DNA that fell to undetectable levels during long-term monitoring. CONCLUSIONS: Plasma cfEBV DNA in patients with NPC appears to be an early sign of tumor recurrence, especially extrapulmonary metastases.

Development of a Nomogram Model for Treatment of Elderly Patients with Locoregionally Advanced Nasopharyngeal Carcinoma.

(1) Purpose: This study aims to explore risk-adapted treatment for elderly patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC) according to their pretreatment risk stratification and the degree of comorbidity. (2) Methods: A total of 583 elderly LA-NPC patients diagnosed from January 2011 to January 2018 are retrospectively studied. A nomogram for disease-free survival (DFS) is constructed based on multivariate Cox regression analysis. The performance of the model is evaluated by using the area under the curve (AUC) of the receiver operating characteristic curve and Harrell concordance index (C-index). Then, the entire cohort is divided into different risk groups according to the nomogram cutoff value determined by X-tile analysis. The degree of comorbidities is assessed by the Charlson Comorbidity Index (CCI). Finally, survival rates are estimated and compared by the Kaplan-Meier method and the log-rank test. (3) Results: A nomogram for DFS is constructed with T/N classification, Epstein-Barr virus DNA and albumin. The nomogram shows well prognostic performance and significantly outperformed the tumor-node-metastasis staging system for estimating DFS (AUC, 0.710 vs. 0.607; C-index, 0.668 vs. 0.585; both p < 0.001). The high-risk group generated by nomogram has significantly poorer survival compared with the low-risk group (3-year DFS, 76.7% vs. 44.6%, p < 0.001). For high-risk patients with fewer comorbidities (CCI = 2), chemotherapy combined with radiotherapy is associated with significantly better survival (p < 0.05) than radiotherapy alone. (4) Conclusion: A prognostic nomogram for DFS is constructed with generating two risk groups. Combining risk stratification and the degree of comorbidities can guide risk-adapted treatment for elderly LA-NPC patients.

Prognostic value of radiation interruption in different periods for nasopharyngeal carcinoma patients in the intensity-modulated radiation therapy era.

We aimed to investigate the prognostic value of radiation interruptions at different times on the overall survival (OS) and disease-free survival (DFS) of patients with nasopharyngeal carcinoma receiving intensity-modulated radiation therapy. Totally, 4510 patients were identified from a well-established big-data intelligence platform. Optimal interruption thresholds were identified using Recursive partitioning analyses. Actuarial rates were plotted using the Kaplan-Meier method and were compared using the log-rank test. Patients with preceding interruptions ≥1 d (5-year OS, 89.6% vs. 85.7%, p < 0.001; 5-year DFS, 81.4% vs. 76.4%, p < 0.001), or latter interruptions ≥4 d (88.4% vs. 82.3%, p < 0.001; 79.2% vs. 75.1%, p = 0.006) showed significant detrimental effects on OS and DFS than patients without those interruptions. However, no significant lower survival was identified in latter interruptions ≥1 d (5-year OS: 89.0% vs. 86.7%, p = 0.053; 5-year DFS, 80.2% vs. 77.8%, p = 0.080). Latter interruptions ≥4 d was an independent unfavorable prognostic factor for OS (HR, 1.404; 95% CI, 1.143-1.723, p = 0.001) and DFS (HR, 1.351; 95% CI, 1.105-1.652, p = 0.003) in multivariate analysis. Radiation interruptions longer than 3 days that occurred in the latter period of treatment with IMRT were independent factors in poorer survival. Efforts are needed to minimize radiation interruptions and improve the timely provision of treatment.

Normal tissue complication probability (NTCP) models for predicting temporal lobe injury after intensity-modulated radiotherapy in nasopharyngeal carcinoma: A large registry-based retrospective study from China.

PURPOSE: To develop predictive models with dosimetric and clinical variables for temporal lobe injury (TLI) in nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Data of 8194 NPC patients who received IMRT-based treatment were retrospectively reviewed. TLI was diagnosed by magnetic resonance imaging. Dosimetric factors were selected by penalized regression and machine learning, with area under the receiver operating curve (AUC) calculated. Cox proportional hazards models containing the most predictive dosimetric factor with/without clinical variables were performed. A nomogram was generated as a visualization of Cox regression for predicting TLI-free survival. RESULTS: During median follow-up of 66.8 months (interquartile range [IQR] 54.2-82.2 months), 12.1% of patients (989/8194) developed TLI. Median latency from IMRT to TLI was 36 months (IQR 28-47 months). D0.5cc (dose delivered to 0.5-cm3 temporal-lobe volume) was the most predictive dosimetric factor (AUC: 0.799). Tolerance dose for 5% and 50% probabilities to develop TLI in 5 years were 65.06 Gy (95% confidence interval [CI]: 64.19-65.92) and 89.75 Gy (95% CI: 87.39-92.11), respectively. A nomogram comprising age, T stage, and D0.5cc significantly outperformed the model with only D0.5cc in predicting TLI (C-index: 0.78 vs. 0.737 in train set; 0.775 vs. 0.73 in test set; both P < 0.001). The nomogram-defined high-risk group had worse 5-year TLI-free survival. CONCLUSIONS: D0.5cc of 65.06 Gy was the tolerance dose of the temporal lobe. Reducing D0.5cc decreased risk of TLI, especially in older patients with advanced T stage. The nomogram could predict TLI precisely and allow individualized follow-up management.

Development and validation of a web-based calculator to predict individualized conditional risk of site-specific recurrence in nasopharyngeal carcinoma: Analysis of 10,058 endemic cases.

BACKGROUND: Conditional survival (CS) provides dynamic prognostic estimates by considering the patients existing survival time. Since CS for endemic nasopharyngeal carcinoma (NPC) is lacking, we aimed to assess the CS of endemic NPC and establish a web-based calculator to predict individualized, conditional site-specific recurrence risk. METHODS: Using an NPC-specific database with a big-data intelligence platform, 10,058 endemic patients with non-metastatic stage I-IVA NPC receiving intensity-modulated radiotherapy with or without chemotherapy between April 2009 and December 2015 were investigated. Crude CS estimates of conditional overall survival (COS), conditional disease-free survival (CDFS), conditional locoregional relapse-free survival (CLRRFS), conditional distant metastasis-free survival (CDMFS), and conditional NPC-specific survival (CNPC-SS) were calculated. Covariate-adjusted CS estimates were generated using inverse probability weighting. A prediction model was established using competing risk models and was externally validated with an independent, non-metastatic stage I-IVA NPC cohort undergoing intensity-modulated radiotherapy with or without chemotherapy (n = 601) at another institution. RESULTS: The median follow-up of the primary cohort was 67.2 months. The 5-year COS, CDFS, CLRRFS, CDMFS, and CNPC-SS increased from 86.2%, 78.1%, 89.8%, 87.3%, and 87.6% at diagnosis to 87.3%, 87.7%, 94.4%, 96.0%, and 90.1%, respectively, for an existing survival time of 3 years since diagnosis. Differences in CS estimates between prognostic factor subgroups of each endpoint were noticeable at diagnosis but diminished with time, whereas an ever-increasing disparity in CS between different age subgroups was observed over time. Notably, the prognoses of patients that were poor at diagnosis improved greatly as patients survived longer. For individualized CS predictions, we developed a web-based model to estimate the conditional risk of local (C-index, 0.656), regional (0.667), bone (0.742), lung (0.681), and liver (0.711) recurrence, which significantly outperformed the current staging system (P < 0.001). The performance of this web-based model was further validated using an external validation cohort (median follow-up, 61.3 months), with C-indices of 0.672, 0.736, 0.754, 0.663, and 0.721, respectively. CONCLUSIONS: We characterized the CS of endemic NPC in the largest cohort to date. Moreover, we established a web-based calculator to predict the CS of site-specific recurrence, which may help to tailor individualized, risk-based, time-adapted follow-up strategies.

Assessment of Modifiable Factors for the Association of Marital Status With Cancer-Specific Survival.

Importance: Married patients with cancer have better cancer-specific survival than unmarried patients. Increasing the early diagnosis and definitive treatment of cancer among unmarried patients may reduce the survival gap. Objectives: To evaluate the extent to which marriage is associated with cancer-specific survival, stage at diagnosis, and treatment among patients with 9 common solid cancers and to recommend methods for reducing the survival gap. Design, Setting, and Participants: This retrospective, population-based cohort study included patients older than 18 years who were diagnosed with 1 of 9 common cancers between January 1, 2007, and December 31, 2016. Patient data were retrieved from the Surveillance, Epidemiology, and End Results Program. Statistical analyses were performed from August 1 to October 1, 2020. Exposures: Marital status, classified as married and unmarried (including single, separated, divorced, widowed, and unmarried patients or domestic partners). Main Outcomes and Measures: The primary outcome was the time ratio (TR) of cancer-specific survival (married vs unmarried). Mediation analyses were conducted to determine the extent to which the association of marriage with cancer-specific survival was mediated by stage at diagnosis and treatment. Results: This study included 1 733 906 patients (894 379 [51.6%] women; 1 067 726 [61.6%] married; mean [SD] age, 63.76 [12.60] years). Multivariate analyses found that those who were married were associated with better cancer-specific survival than unmarried patients (TR, 1.36; 95% CI, 1.35-1.37). Early diagnosis in breast cancer, colorectal cancer, endometrial cancer, and melanoma mediated the association between marital status and cancer-specific survival (breast cancer: proportion mediated [PM], 11.4%; 95% CI, 11.2%-11.6%; colorectal cancer: PM, 10.9%; 95% CI, 10.7%-11.2%; endometrial cancer: PM, 12.9%; 95% CI, 12.5%-13.3%; melanoma: PM, 12.0%; 95% CI, 11.7-12.4%). Surgery mediated the association between marital status and cancer-specific survival in lung (PM, 52.2%; 95% CI, 51.9%-52.4%), pancreatic (PM, 28.9%; 95% CI, 28.6%-29.3%), and prostate (PM, 39.3%; 95% CI, 39.0%-39.6%) cancers. Chemotherapy mediated the association of marital status with cancer-specific survival in lung (PM, 37.7%; 95% CI, 37.6%-37.9%) and pancreatic (PM, 28.6%; 95% CI, 28.4%-28.9%) cancers. Improved cancer-specific survival associated with marriage was greater among men than women (men: TR, 1.27; 95% CI, 1.25-1.28; women: TR, 1.20; 95% CI, 1.19-1.21). The contribution of receiving an early diagnosis and treatment with surgery or chemotherapy to the association between marital status and cancer-specific survival was greater among men than women (early diagnosis: PM, 21.7% [95% CI, 21.5%-21.9%] vs PM, 20.3% [95% CI, 20.2%-20.4%]; surgery: PM, 26.6% [95% CI, 26.4%-26.7%] vs PM, 11.1% [95% CI, 11.0%-11.2%]; chemotherapy: PM, 6.8% [95% CI, 6.7%-6.8%] vs PM, 5.1% [95% CI, 5.0%-5.2%]). Conclusions and Relevance: In this study, survival disparities associated with marital status were attributable to early diagnosis in breast, colorectal, and endometrial cancers as well as melanoma and to treatment-related variables in lung, pancreatic, and prostate cancers. The findings also suggest that marriage may play a greater protective role in the cancer-specific survival of men than of women.

Individualized cumulative cisplatin dose for locoregionally-advanced nasopharyngeal carcinoma patients receiving induction chemotherapy and concurrent chemoradiotherapy.

OBJECTIVES: To screen subgroup potentially benefiting from cumulative cisplatin dose (CCD) ≥ 200 mg/m2 during concurrent chemoradiotherapy (CCRT) of patients with locoregionally-advanced nasopharyngeal carcinoma (LA-NPC) receiving induction chemotherapy (IC) and CCRT. MATERIALS AND METHODS: In total, 2 063 patients with non-disseminated LA-NPC diagnosed from 2009 to 2015 receiving IC plus CCRT were enrolled. Patients were restaged based on proposed stage groupings and risk groupings was established. After propensity score matching, survival outcomes were compared within different risk groupings with 200 mg/m2 CCD. Post-IC gross primary tumor (GTVp) and lymph node (GTVnd) volumes were calculated from planning computed tomography. The role of risk groupings and post-IC tumor volume to CCD was explored. RESULTS: Compared with the low-risk group, the high-risk group showed poor survival outcomes in terms of 5-year progression-free survival (PFS), overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS). CCD ≥ 200 mg/m2 improved survival in terms of 5-year PFS, OS and DMFS in the high-risk group but not in the low-risk group. High-risk patients with unfavorable response to IC benefited from CCD ≥ 200 mg/m2 with respect to PFS and DMFS; while those in low-risk group or with favorable response to IC didn't. CONCLUSIONS: Risk groupings was effective for risk stratification. Combining risk groupings and post-IC tumor volume is a simple and useful method to guide individualized CCD treatment of CCRT for patients with LA-NPC receiving IC and CCRT. CCD ≥ 200 mg/m2 may be indicated for high-risk patients with unfavorable response to IC.

The Role of Post-Neoadjuvant Chemotherapy Tumor Volume for Prognostication and Treatment Guidance in Loco-Regionally Advanced Nasopharyngeal Carcinoma.

The value of post-neoadjuvant chemotherapy (NACT) tumor volume for prognostication in loco-regionally advanced nasopharyngeal carcinoma (LA-NPC) is unascertained. Here, we recruited 4109 histologically proven LA-NPC (stage III-IVA) that were treated with radical chemo-intensive-modulated radiotherapy (IMRT). Post-NACT gross primary tumor (GTVp) and lymph node (GTVnd) volumes of each patient were calculated from planning computed tomography (CT). We observed similar linear association between GTVp/GTVnd and overall survival (OS); thresholds of 52 cm3 for GTVp and 12 cm3 for GTVnd were consistent for risk discretization for OS, disease-free survival (DFS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS). Recursive partitioning analysis (RPA) modelling incorporating T-/N-categories and GTVp/GTVnd yielded four T-N-volume (TNV) risk groupings with disparate OS (p < 0.001). TNV risk stratification outperformed GTVp/GTVnd and eighth edition TNM for predicting OS (AUC 0.643 vs. 0.541-0.591; p < 0.001), DFS (0.629 vs. 0.545-0.580; p < 0.001), and DMFS (0.652 vs. 0.522-0.621; p < 0.001). NACT + concurrent chemoradiotherapy (CCRT) over NACT + IMRT was not superior for low- and low-intermediate-risk groupings (p > 0.05 for both), but superior for intermediate- and high-risk groupings in terms of OS (HR 0.68 (95% CI 0.47-0.99) for intermediate risk, 0.73 (0.55-0.97) for high risk; both p < 0.05). Overall, GTVp/GTVnd represent effective indicators for prognostication and decision-making in LA-NPC after NACT.