Prognostic factors in metastatic nasopharyngeal carcinoma

Machine learning explainability in nasopharyngeal cancer survival using LIME and SHAP

Nasopharyngeal cancer (NPC) has a unique histopathology compared with other head and neck cancers. Individual NPC patients may attain different outcomes. This study aims to build a prognostic system by combining a highly accurate machine learning model (ML) model with explainable artificial intelligence to stratify NPC patients into low and high chance of survival groups. Explainability is provided using Local Interpretable Model Agnostic Explanations (LIME) and SHapley Additive exPlanations (SHAP) techniques. A total of 1094 NPC patients were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database for model training and internal validation. We combined five different ML algorithms to form a uniquely stacked algorithm. The predictive performance of the stacked algorithm was compared with a state-of-the-art algorithm-extreme gradient boosting (XGBoost) to stratify the NPC patients into chance of survival groups. We validated our model with temporal validation (n = 547) and geographic external validation (Helsinki University Hospital NPC cohort, n = 60). The developed stacked predictive ML model showed an accuracy of 85.9% while the XGBoost had 84.5% after the training and testing phases. This demonstrated that both XGBoost and the stacked model showed comparable performance. External geographic validation of XGBoost model showed a c-index of 0.74, accuracy of 76.7%, and area under curve of 0.76. The SHAP technique revealed that age of the patient at diagnosis, T-stage, ethnicity, M-stage, marital status, and grade were among the prominent input variables in decreasing order of significance for the overall survival of NPC patients. LIME showed the degree of reliability of the prediction made by the model. In addition, both techniques showed how each feature contributed to the prediction made by the model. LIME and SHAP techniques provided personalized protective and risk factors for each NPC patient and unraveled some novel non-linear relationships between input features and survival chance. The examined ML approach showed the ability to predict the chance of overall survival of NPC patients. This is important for effective treatment planning care and informed clinical decisions. To enhance outcome results, including survival in NPC, ML may aid in planning individualized therapy for this patient population.

Local radiotherapy versus nonradiotherapy to distant lesions for metastatic nasopharyngeal carcinoma: A retrospective cohort study

BACKGROUND

To evaluate the efficiency of local radiotherapy to metastatic lesions in patients with metastatic nasopharyngeal carcinoma (mNPC).

METHODS

The overall survival was observed and compared for mNPC patients who received local radiotherapy versus nonradiotherapy to metastatic lesions by using the Kaplan-Meier method and Cox analysis.

RESULTS

One hundred and nine patients with NPC were involved in this study, with 61 (56.0%) received radiotherapy to metastatic sites and 48 (44.0%) did not receive radiotherapy to metastatic sites. The 2- and 5-year OS for patients who received local radiotherapy to metastatic lesions were 65.8% and 35.7%, and for patients who did not receive radiotherapy to metastatic lesions were 45.3% and 26.2%. The multivariable adjusted hazard radios for local radiotherapy versus nonradiotherapy to metastatic lesions were 0.482 (95% confidence interval is 0.278-0.834, p = 0.009).

CONCLUSIONS

Local radiotherapy to metastatic lesions might be a protective factor for patients with mNPC.

Metastatic characteristics associated with survival of synchronous metastatic nasopharyngeal carcinoma in non-epidemic areas

INTRODUCTION

The current metastatic category (M) of nasopharyngeal carcinoma (NPC) is a "catch-all" category, we previously successfully established a M1 subdivision system based on prognostic metastatic characteristics in epidemic areas. We aimed to figure out metastatic characteristics associated with survival outcomes of NPC in non-epidemic areas.

METHODS

A total of 428 newly diagnosed de novo metastatic NPC patients from 2010 to 2016 were analyzed from the population-based Surveillance, Epidemiology, and End Results program. Cox proportional hazard ratios (HRs) were used to identify independent prognostic factors for survival.

RESULTS

The most frequently involved metastatic locations were the bones (53.04%), the lungs (36.68%), the livers (29.21%) and the distant lymph nodes (24.07%). Univariate analysis indicated that bone involvement (HR = 1.39, 95% CI = 1.09-1.77), liver involvement (HR = 1.44, 95% CI = 1.12-1.85) and multiple metastatic locations (HR = 1.32, 95% CI = 1.04-1.67) were negative prognostic factors of overall survival (OS) for patients with synchronous metastasis. We established a new M1 subdivision system based on metastatic characteristics: M1a, without bone and liver involvement; M1b, single bone or liver involvement; M1c, multiple metastatic locations including bone and/or liver. Multivariate analysis confirmed that our new subcategories were associated with significantly different OS (M1b vs M1a: HR = 1.54, 95% CI = 1.11-2.16; M1c vs M1a: HR = 2.03, 95% CI = 1.47-2.78).

CONCLUSIONS

Synchronous metastatic NPC patients with multiple metastatic locations involved bone and/or liver were prone to suffer from dismal OS and might need more attentions for selection of treatment modality.

Prognostic model and optimal treatment for patients with stage IVc nasopharyngeal carcinoma at diagnosis

The treatment for patients with stage IVc nasopharyngeal carcinoma (NPC) at diagnosis was still controversial. In this study, we tried to build a prognostic score model and optimize the treatment for the patients. The prognostic model was based on the primary cohort involving 289 patients from 2002 to 2011 and the validation involving another 156 patients from 2012 to 2015.The prognostic model was built based on the hazard ratios of significant prognostic factors for overall survival (OS). By multivariate analysis, factors associated with poor OS were Karnofsky performance score ≤70, liver metastases, multiple-organ metastases, ≥2 metastatic lesions, lactate dehydrogenase >245 IU/I and poor response to chemotherapy (all P < 0.01). Based on these prognostic factors, patients were divided into the low-risk (0-2 points), intermediate-risk (3-6 points) and high-risk (≥7 points) groups. Five-year OS rates for the low-, intermediate- and high-risk groups were 49.3%, 9.7% and 0.0%, respectively (P < 0.01). Furthermore, loco-regional radiotherapy was associated with significantly better OS in low- and intermediate-risk patients, but not in high-risk patients. These results demonstrated that the prognostic score model based on six negative factors can effectively predict OS in patients with stage IVc NPC at diagnosis. Loco-regional radiotherapy may be beneficial for low- and intermediate-risk patients, but not for high-risk patients.

Glycyrrhiza glabra suppresses nasopharyngeal carcinoma cell proliferation through inhibiting the expression of lncRNA, AK027294

Glycyrrhiza glabra is considered as potential drug for nasopharyngeal carcinoma (NPC). However, whether the long noncoding RNAs' (lncRNAs) contributes to the anti-cancer function of this herb is unknown. In present study, we analyzed the differential expression of lncRNA between G. glabra-treated and untreated C666-1 cells. Out of those tumor-related lncRNAs, AK027294 had a strongest down-regulation upon G. glabra treatment. Knockdown of AK027294 suppresses the proliferation of C666-1 cells by inducing the apoptosis. Moreover, either G. glabra treatment or knockdown of AK027294 significantly increases the production of EZH1 (Enhancer of zeste 1 polycomb repressive complex 2 subunit). Collectively, we have identified a potential mechanism that the down-regulation of AK027294 contributes to the anti-cancer function of G. glabra and also provide the potential inter-relationship between AK027294 and EZH1.

A Nomogram for the Prediction of Prognosis in Patients With Distant Metastases of Nasopharyngeal Carcinoma

Background: Patients with metastatic nasopharyngeal carcinoma (NPC) have heterogeneous survival outcomes. This study aimed to establish an effective prognostic nomogram for patients with NPC with distant metastases using easily determined factors.

Methods: The nomogram was based on a retrospective study of 103 patients with metastatic NPC at the First Affiliated Hospital of Xiamen University during January 2009–March 2016. Nomogram performance was evaluated using a concordance index (C-index) and assessed using calibration plot. Bootstraps with 1,000 resamples were applied to these analyses.

Results: In univariate and multivariate Cox proportional hazards model analyses, chemotherapy, metastatic liver involvement, number of tumor metastases, N stage and derived neutrophil–lymphocyte ratio correlated with overall survival (OS). The recurrence probability calibration curve indicated good agreement between nomogram-based predictions and actual observations. For OS predictions, the nomogram had a C-index of 0.824 (95% confidence interval, 0.74–0.91). The stratification by nomogram score of patients into different subgroups showed significant distinction.

Conclusion: This novel nomogram comprises factors that are easily determined at most hospitals and can predict survival in patients with distant metastases of NPC. This model can precisely estimate the survival of individual patients and identify subgroups of patients requiring specific therapeutic strategies.

KAI1/CD82 Genetically Engineered Endothelial Progenitor Cells Inhibit Metastasis of Human Nasopharyngeal Carcinoma in a Mouse Model

Background

Endothelial progenitor cells (EPCs) are regarded as promising targeted vectors for delivering therapeutic genes or agents in cancer therapy. The purpose of this study was to investigate the role of intravenously administered KAI1/CD82 genetically transduced EPCs in the tumorigenesis and metastasis of nasopharyngeal carcinoma (NPC).

Material/Methods

EPCs were isolated from human umbilical cord blood, expanded in culture, and stably transduced with lentiviral vectors expressing KAI1/CD82. The KAI1/CD82 EPCs were injected intravenously into nude mice bearing human NPC xenografts. Tumor growth and the incidence of liver and lung metastases were observed. Expression of KAI1/CD82 was determined by immunofluorescent staining.

Results

The NPC model was successfully established. Tumor growth was not suppressed when mice were injected with KAI1/CD82 EPCs (KAI1/CD82 EPCs group) compared with when non-transduced EPCs was present (EPCs group) or the control (1.485±0.234, 1.388±0.204, and 1.487±0.223g, respectively; P>0.05). However, the incidence of lung metastasis was significantly reduced in the KAI1/CD82⁺ EPCs group compared with the EPCs group and the control group (10%, 55% and 45%, respectively; P=0.005), and there was a significant decrease in the number of metastatic foci on the lung surface (17.50±3.54, 34.27±5.35, and 38.44±9.63 respectively; P=0.007). Moreover, KAI1/CD82 was expressed in lung metastatic foci of the KAI1/CD82 EPCs group, but not in the EPCs group and control group.

Conclusions

EPCs can be used as a delivery vehicle for suppressor genes KAI1/CD82 to NPC, and the migration of KAI1/CD82 genetically engineered EPCs can inhibit NPC lung metastasis in a mouse model.

Improved overall survival in head and neck cancer patients after specific therapy of distant metastases

PURPOSE

While metastases directed therapy for oligometastatic disease is recommended in different cancer entities, the treatment of solitary metastases in head and neck squamous cell carcinoma (HNSCC) patients is not clearly defined.

METHODS

A retrospective analysis was performed on data from 143 HNSCC patients treated between 2001 and 2016 in a tertiary university hospital. Clinical factors and outcome were measured using the median survival of patients receiving metastases specific therapy in comparison with matched control patients.

RESULTS

In 37 patients, distant metastases were treated specifically with either surgery and/or stereotactic ablative radiotherapy and had with 23.97 months a more than three times higher median survival than 10 untreated matched controls with potentially treatable distant metastases (7.07 months).

CONCLUSIONS

Our retrospective analysis demonstrates a significant survival benefit for HNSCC patients who received a specific therapy regarding distant metastasis irrespective of localization as compared to a matched control cohort.

The combination of systemic therapy and locoregional radiotherapy prolongs survival in newly diagnosed metastatic nasopharyngeal carcinoma patients

Background

The purpose of this study is to assess the role of locoregional radiotherapy (RT) when used in combination with systemic chemotherapy, for patients with newly diagnosed metastatic nasopharyngeal carcinoma (NPC), in a non-endemic region of northern China.

Methods

In total, 611 patients with NPCs were newly diagnosed between June 2011 and June 2016 following visits to our hospital; of these, 32 patients presented with metastasis at initial diagnosis. Among these 32 patients, 29 had single-organ metastasis and 3 had multiple-organ metastasis. All patients were treated with RT for local and regional disease.

Results

The median follow-up for all patients was 20 months (range 9-59 months), and median survival was not achieved (some patients had succumbed) at the time of the last follow-up. The 2-year overall survival (OS) rate was 75.2%, and 3-year OS rate was 50.1%. There was a significant difference between patients with single- and multiple-organ metastasis: 2-year OS was 67.5% for single- vs 0% for multiple-organ metastasis (p=0.039). Patients treated with intensity-modulated RT had a better prognosis than patients treated by conventional RT: 2-year OS was 76.6% for single- vs 44.4% for multiple-organ metastasis (no significant difference was found between the 2 groups, p=0.297). For patients with progression (all were with distant disease progression), the median progression time was 8 months (6-22 months), and the median survival after disease progression was 6 months (2-14 months).

Conclusion

For patients with newly diagnosed metastatic NPCs, especially with single-organ metastasis, the addition of RT to systemic chemotherapy improved survival and disease control compared with historical cohort.

Prognostic stratification of patients with metastatic nasopharyngeal carcinoma using a clinical and biochemical scoring system

PURPOSE

Metastatic nasopharyngeal cancer (NPC) is known to have poor survival outcomes. Clinical and biochemical parameters may impact survival outcomes among patients with metastatic NPC and may be used for prognostication.

METHODS

One-hundred and fifty-eight patients with metastatic NPC treated at a single tertiary institution were analyzed retrospectively. Multivariate analysis was carried out on patients who were given disease control treatment (n = 135). A numerical score derived from the regression coefficients of each identified independent variable was used to create prognostic groups (PG). A p value of less than 0.05 was considered significant.

RESULTS

Independent negative prognostic factors included ECOG status >1, LDH level >580 U/L, hemoglobin level <12.0 g/dL and having more than one metastatic organ involvement. Three PGs were obtained: low risk (total score = 0), intermediate risk (1-2) and high risk (3-4). Median survivals of the 3 groups (low, intermediate and high risk) were 57.1, 18.1 and 8.0 months for the three different risk groups, respectively (p < 0.001).

CONCLUSION

Risk stratification of patients with metastatic nasopharyngeal cancer is possible using a prognostic scoring system based on clinical and biochemical parameters. Patients with low-risk score may achieve good metastatic survival and may benefit from additional therapy for disease control.

A nomogram for predicting survival of nasopharyngeal carcinoma patients with metachronous metastasis

Patients with metachronous metastatic nasopharyngeal carcinoma (NPC) differ significantly in survival outcomes. The aim of this study is to build a clinically practical nomogram incorporating known tumor prognostic factors to predict survival for metastatic NPC patients in epidemic areas.A total of 860 patients with metachronous metastatic nasopharyngeal carcinoma were analyzed retrospectively. Variables assessed were age, gender, body mass index, Karnofsky Performance Status (KPS), Union for International Cancer Control (UICC) T and N stages, World Health Organization (WHO) histology type, serum lactate dehydrogenase (sLDH) level, serum Epstein-Barr virus (EBV) level, treatment modality, specific metastatic location (lung/liver/bone), number of metastatic location(s) (isolated vs multiple), and number of metastatic lesion(s) in metastatic location(s) (single vs multiple). The independent prognostic factors for overall survival (OS) by Cox-regression model were utilized to build the nomogram.Independent prognostic factors for OS of metastatic NPC patients included age, UICC N stage, KPS, sLDH, number of metastatic locations, number of metastatic lesions, involvement of liver metastasis, and involvement of bone metastasis. Calibration of the final model suggested a c-index of 0.68 (95% confidence interval [CI], 0.65-0.69). Based on the total point (TP) by nomogram, we further subdivided the study cohort into 4 groups. Group 1 (TP < 320, 208 patients) had the lowest risk of dying. Discrimination was visualized by the differences in survival between these 4 groups (group 2/group 1: hazard ratio [HR] = 1.61, 95%CI: 1.24-2.09; group 3/group 1: HR = 2.20, 95%CI: 1.69-2.86; and group 4/group 1: HR = 3.66, 95%CI: 2.82-4.75).The developed nomogram can help guide the prognostication of patients with metachronous metastatic NPC in epidemic areas.

Overexpression of the PSAT1 Gene in Nasopharyngeal Carcinoma Is an Indicator of Poor Prognosis

Purpose: Nasopharyngeal carcinoma (NPC) is a common cancer in southern China and Southeast Asia, but risk stratification and treatment outcome in NPC patients remain suboptimal. Our study identified and validated metabolic drivers that are relevant to the pathogenesis of NPC using a published transcriptome. Phosphoserine aminotransferase 1 (PSAT1) is an enzyme that is involved in serine biosynthesis, and its overexpression is associated with colon cancer, non-small cell lung cancer and breast cancer. However, its expression has not been systemically evaluated in patients with NPC.

Materials and Methods: We evaluated two public transcriptomes of NPC tissues and benign nasopharyngeal mucosal epithelial tissues that deposited in the NIH Gene Expression Omnibus database under accession number GSE34574 and GSE12452. We also performed immunohistochemical staining and assessment of PSAT1 in a total of 124 NPC patients received radiotherapy and were regularly followed-up until death or loss. The endpoints analyzed were local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS).

Results: We retrospectively evaluated 124 patients with NPC and found that high PSAT1 expression was associated with poor prognosis of NPC and indicator of advanced tumor stage. High PSAT1 expression also correlated with an aggressive clinical course, with significantly shorter DSS (HR= 2.856, 95% CI 1.599 to 5.101), DMFS (HR= 3.305, 95% CI 1.720 to 6.347), LRFS (HR= 2.834, 95% CI 1.376 to 5.835), and OS HR= 2.935, 95% CI 1.646-5.234) in multivariate analyses.

Conclusions: Our study showed that PSAT1 is a potential prognostic biomarker and higher expression of PSAT1 is associated with a poor prognosis in NPC.

Multimodality Treatment May Improve the Survival Rate of Patients with Metastatic Nasopharyngeal Carcinoma with Good Performance Status

The aim of the present study was to evaluate the benefit of chemotherapy, combined with palliative radiotherapy (PRT) and other local treatments to the metastatic sites, for patients with metastatic nasopharyngeal carcinoma (NPC) who had a performance status 0-2. We conducted a retrospective review of available data from 197 biopsy-proven NPC patients who developed metastasis after their initial definitive treatment. These patients were grouped into three categories according to the different treatment paths that were followed: the best supportive care (64 patients), chemotherapy alone (55 patients), and multimodality treatment with chemotherapy combined with PRT and other local treatments to metastatic sites (78 patients). The 2-year metastatic survival rate of patients in the multimodality treatment group was 57.7%, which was significantly better than that of the patients in both the chemotherapy alone group and the best supportive care group (32.7% and 1.6%, respectively). The independent significant factors affecting survival were the disease-free interval prior to the detection of metastatic disease, the number of metastases, the number of chemotherapy cycles and the biological effective dose of PRT. In conclusion, multimodality treatment may improve survival of select patients with recurrent NPC with distant metastases.

miR-29a/b enhances cell migration and invasion in nasopharyngeal carcinoma progression by regulating SPARC and COL3A1 gene expression

Nasopharyngeal carcinoma (NPC) is a malignant tumor associated with a genetic predisposition, Epstein-Barr virus infection and chromosomal abnormalities. Recently, several miRNAs have been shown to target specific mRNAs to regulate NPC development and progression. However, the involvement of miRNAs in processes leading to NPC migration and invasion remains to be elucidated. We predicted that miR-29a/b are associated with dysregulated genes controlling NPC through an integrated interaction network of miRNAs and genes. miR-29a/b over-expression in NPC cell lines had no significant effect on proliferation, whereas miR-29b mildly increased the percentage of cells in the G1 phase with a concomitant decrease in the percentage of cells in S phase. Furthermore, we demonstrated that miR-29a/b might be responsible for increasing S18 cell migration and invasion, and only COL3A1 was identified as a direct target of miR-29b despite the fact that both SPARC and COL3A1 were inhibited by miR-29a/b over-expression. Meanwhile, SPARC proteins were increased in metastatic NPC tissue and are involved in NPC progression. Unexpectedly, we identified that miRNA-29b expression was elevated in the serum of NPC patients with a high risk of metastasis. The 5-year actuarial overall survival rates in NPC patients with high serum miR-29b expression was significantly shorter than those with low serum miR-29b expression; therefore, serum miR-29b expression could be a promising prognostic marker.

Fate of patients with nasopharyngeal cancer who developed distant metastasis as first failure after definitive radiation therapy

BACKGROUND

No consensus has been reached on the optimal treatment for patients with nasopharyngeal cancer (NPC) who develop distant metastasis after initial radiation therapy (RT).

METHODS

Two hundred eighty-two patients with NPC received curative RT (+/- chemotherapy). Forty-six patients (16.3%) who developed distant metastasis as first failure formed the study group for the current analysis.

RESULTS

The median interval from initial RT until distant metastasis was 11.6 months. With a median follow-up of 30 months among survivors, overall survival (OS) rates at 2 and 5 years were 53.7% and 30.5%, respectively. On multivariate analyses, 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT for initial staging, RT plus chemotherapy as initial treatment, metastatic lesion number <6, disease-free interval >9 months, distant metastasis only to lungs, and treatment with curative intent after distant metastasis were predictive of significantly better OS.

CONCLUSION

Combined with FDG-PET/CT, an aggressive treatment approach using locoregional modalities might be beneficial to patients with NPC with favorable prognostic factors, even after distant metastasis. © 2015 Wiley Periodicals, Inc. Head Neck 38: E293-E299, 2016.

Partial hepatectomy for liver metastases from nasopharyngeal carcinoma: a comparative study and review of the literature

BACKGROUND

The management of liver metastases from nasopharyngeal carcinoma (NPC) has not been extensively investigated. This study aimed to compare the long-term outcome of patients with liver metastases from NPC who were treated by a partial hepatectomy or transcatheter hepatic artery chemoembolization (TACE).

METHODS

Between January 1993 and December 2010, 830 patients were diagnosed with liver metastases from NPC and exhibited a complete response to the primary cancer of the nasopharynx and regional lymph nodes. Fifteen patients with intrahepatic metastasis underwent R0 partial hepatectomy. As a parallel control group, another 15 patients with a resectable liver metastasis who underwent TACE were selected. Prior to the resection and TACE that were performed on patients in these two groups, radical radiotherapy with or without adjuvant chemotherapy was administered. Clinicopathological data and treatment outcomes were compared retrospectively.

RESULTS

No significant differences were observed between the two groups in terms of the clinicopathological features, which include gender ratio, liver function, accompanying cirrhosis, rate of infection with the hepatitis B virus, tumor size, tumor number, pathological type and preoperative comorbidities. The 1-, 3- and 5-year overall survival rates from the time of hepatectomy were 85.7%, 64.2% and 40.2%, respectively, with a median survival of 45.2 months, whereas the 1-, 3- and 5-year overall survival rates were 53.3%, 26.6% and 20.0% for patients in the control group (P = 0.039), respectively, with a median survival of 14.1 months. The actuarial median progression-free survival (PFS) of the patients in the resection group was 21.2 months, and the 1-, 3- and 5-year PFS rates were 70%, 53% and 18%, respectively. In the control group, the 1-, 3- and 5-year PFS rates were 27%, 7% and 0.0% (P = 0.007), respectively, with a median survival of 4.2 months. Thus far, 5 patients have survived for more than 5 years, and the longest survival time is 168.1 months.

CONCLUSIONS

For patients with limited liver metastases from NPC, hepatectomy provides a survival advantage over TACE. Due to the limited treatment options for patients with liver metastasis from NPC, hepatectomy should be recommended as an optimal treatment. Moreover, perioperative chemotherapy may be associated with an improved prognosis.

Retrospective analysis of 234 nasopharyngeal carcinoma patients with distant metastasis at initial diagnosis: therapeutic approaches and prognostic factors

Purpose

The purpose of this retrospective study was to identify the independent prognostic factors and optimize the treatment for nasopharyngeal carcinoma (NPC) patients with distant metastasis at initial diagnosis.

Methods

A total of 234 patients referred between January 2001 and December 2010 were retrospectively analyzed. Among the 234 patients, 94 patients received chemotherapy alone (CT), and 140 patients received chemoradiotherapy (CRT). Clinical features, laboratory parameters and treatment modality were examined with univariate and multivariate analyses.

Results

The median overall survival (OS) time was 22 months (range, 2-125 months), and the 1-year, 2-year, 3-year overall survival rates were 82.2%, 51.3% and 34.1%. The overall response and disease control rates of metastatic lesions after chemotherapy were 56.0% and 89.8%. The factors associated with poor response were karnofsky performance score (KPS) <80, liver metastasis, lactate dehydrogenase (LDH)>245 IU/L, and number of chemotherapy cycles <4. The 3-year OS of patients receiving CRT was higher than those receiving CT alone (48.2% vs. 12.4%, p<0.001). Subgroup analysis showed that significantly improved survival was also achieved by radiotherapy of the primary tumor in patients who achieved complete remission (CR)/partial remission (PR) or stable disease (SD) of metastatic lesions after chemotherapy. Significant independent prognostic factors of OS were KPS, liver metastasis, levels of LDH, and multiple metastases. Treatment modality, response to chemotherapy and chemotherapy cycles were also associated with OS.

Conclusion

A combination of radiotherapy and chemotherapy seems to have survival benefits for selected patients with distant metastases at initial diagnosis. Clinical and laboratory characteristics can help to guide treatment selection. Prospective randomized studies are needed to confirm the result.

Staging of nasopharyngeal carcinoma--the past, the present and the future

This article reviews the evolution of the International Union Against Cancer/American Joint Committee on Cancer staging system for nasopharyngeal carcinoma. With the increasing availability of newer imaging methods, more sophisticated radiotherapy techniques and rapidly evolving molecular assays, we also examine newer clinical features that might have impact on staging. A new version of the staging system taking into account of some of these factors is also proposed.

Combined high-dose radiation therapy and systemic chemotherapy improves survival in patients with newly diagnosed metastatic nasopharyngeal cancer

OBJECTIVES

To investigate the efficacy of high-dose radiation therapy (RT) to the primary and regional disease in combination with systemic chemotherapy and local treatment to metastatic foci in patients with newly diagnosed metastatic nasopharyngeal carcinoma (NPC).

METHODS

One hundred and five consecutive patients with pathologically confirmed NPC with distant metastasis at diagnosis seen between 1995 and 2002 were reviewed. All were offered cisplatin-based chemotherapy, high-dose RT (>30 Gy) to the head and neck region, and active treatment to the metastatic foci.

RESULTS

Patients' median age was 46 years, and all had a Karnofsky Performance Score of ≥70. Eighty-nine patients (85%) had metastases confined to 1 organ. Ninety-six patients (91%) received at least 1 cycle of chemotherapy and 71 (68%) received greater than 65 Gy of radiation to the head and neck region. With a median follow-up time of 22 months (range: 2 to 142 mo), 90 patients had deceased, and the median survival time of the entire group was 25 months. The 2 and 5-year estimated overall survival rates were 50% and 17%, respectively. Radiation dose of greater than 65 Gy to the primary region (P = 0.05) and number of organs with metastases (single vs. multiple) (P = 0.002) were independent predictive factors for overall survival on log-rank tests. Only moderately severe acute toxicities, such as Radiation Therapy Oncology Group grade 3 mucositis, skin desquamation, and leukocytopenia were observed. No patient experienced grade 4 acute toxicities.

CONCLUSIONS

High-dose RT is indicated for local disease control in patients with metastatic NPC, and may improve survival when actively used with systemic chemotherapy and local treatment for metastatic foci. Patients with single-organ metastases have a better prognosis as compared with those with more widespread metastases.

An efficacy analysis for nasopharyngeal carcinoma screening of different screening intervals

OBJECTIVE

To evaluate the impact of different screening intervals on screening for nasopharyngeal carcinoma (NPC).

METHODS

A Markov model was constructed, based on the natural history of NPC. The 5-year mortality rate of NPC was the major measurement to evaluate the efficacies of 16 screening strategies. Parameters for the model were derived from published literature.

RESULTS

Screening reduced the 5-year mortality rate for NPC by 20.4 - 43.3%, compared with the equivalent rate without screening. The 5 year mortality rate and the NPC pick-up rate with strategy A1 (annual screening) were 23.6% and 83.9%, respectively. Compared with strategy A1, strategy B1 (annual screening for seropositive subjects; biennial screening for seronegative subjects) had a similar 5-year mortality rate (24.0%) and a slightly smaller NPC pick-up rate (81.7%), but led to a 39.3% reduction in total screenings. Compared with all other strategies excluding strategy A1, strategy B1 achieved the lowest 5-year mortality rate and the largest NPC pick-up rate.

CONCLUSIONS

Strategy B1 had the highest efficacy for NPC screening.

Challenges in the modification of the M1 stage of the TNM staging system for nasopharyngeal carcinoma: A study of 1027 cases and review of the literature

A series of modifications have been introduced to the TNM staging system over time for nasopharyngeal carcinoma (NPC), mainly focused on the T (primary tumor) and N (local node) components of the system. The M1 stage is a 'catch all' classification, covering a group of patients whose outlook ranges from potentially curable to incurable. Since the current M1 stage does not allow clinicians to stratify patients according to prognosis or guide therapeutic decision-making and allow comparison of results of radical and non-radical treatments, we aimed to subdivide the M1 stage according to a retrospective study of 1027 metastatic NPC patients and to review the relevant literature. Between 1995 and 2007, 1027 inpatients with distant metastasis from NPC were retrospectively analyzed. Various possible subdivisions of the M1 stage were considered, looking at different metastatic sites, the number of metastatic organs and the number of metastases. Survival rates were calculated using the Kaplan-Meier method and compared using the log-rank test. The most frequently involved metastatic sites were the bone, lung and liver. The incidence rates of solitary metastatic lesions and pulmonary metastasis were 16.2 and 41.3%. Despite the poor survival of these patients with a median survival of 30.8 months, patients in the metachronous metastatic group with metastases to the lung and/or solitary lesions, were defined as M1a, and were significantly associated with favorable median survival of 41.5 and 49.1 months in the univariate and multivariate analysis, respectively. Patients in the metachronous metastatic group with metastasis to the lung and/or solitary lesions (M1a) have a more favorable prognosis compared with those patients with multiple metastases located in other anatomic sites (M1b). These data, in one of the largest reported metastatic NPC cohorts, are the first to show the prognostic impact of metastatic status in NPC. As a powerful predictor, the potential clinical value of a modified M1 of the TNM system for NPC will facilitate patient counseling and individualize management.

Plasma Epstein-Barr virus DNA concentration and clearance rate as novel prognostic factors for metastatic nasopharyngeal carcinoma

BACKGROUND

To investigate the pretreatment copy number and the clearance rate of plasma Epstein-Barr virus (EBV) DNA as novel prognostic outcome markers for metastatic nasopharyngeal carcinoma (NPC).

METHODS

Seventy-three patients with metastatic NPC were treated at outpatient department. Plasma EBV DNA concentrations and half-life values of plasma viral clearance rates, were determined by real-time quantitative polymerase chain reaction.

RESULTS

Treatment response evaluated after 3 to 6 months of treatment showed that the overall response rate was 53.5%. The pretreatment plasma EBV DNA concentrations and the half-life of plasma EBV DNA clearance rates had significant effects on treatment response and overall survival prediction. In the chemotherapy regimen, gemcitabine plus cisplatin had a better treatment outcome than the cisplatin plus oral UFT and calcium folinate-based regimens.

CONCLUSIONS

The pretreatment plasma EBV DNA copy number and their clearance rates are significant predictors for NPC treatment outcome.

Prognosticators and risk grouping in patients with lung metastasis from nasopharyngeal carcinoma: a more accurate and appropriate assessment of prognosis

Background

Lung metastases arising from nasopharyngeal carcinomas (NPC) have a relatively favourable prognosis. The purpose of this study was to identify the prognostic factors and to establish a risk grouping in patients with lung metastases from NPC.

Methods

A total of 198 patients who developed lung metastases from NPC after primary therapy were retrospectively recruited from January 1982 to December 2000. Univariate and multivariate analyses of clinical variables were performed using Cox proportional hazards regression models. Actuarial survival rates were plotted against time using the Kaplan-Meier method, and log-rank testing was used to compare the differences between the curves.

Results

The median overall survival (OS) period and the lung metastasis survival (LMS) period were 51.5 and 20.9 months, respectively. After univariate and multivariate analyses of the clinical variables, age, T classification, N classification, site of metastases, secondary metastases and disease-free interval (DFI) correlated with OS, whereas age, VCA-IgA titre, number of metastases and secondary metastases were related to LMS. The prognoses of the low- (score 0-1), intermediate- (score 2-3) and high-risk (score 4-8) subsets based on these factors were significantly different. The 3-, 5- and 10-year survival rates of the low-, intermediate- and high-risk subsets, respectively (P < 0.001) were as follows: 77.3%, 60% and 59%; 52.3%, 30% and 27.8%; and 20.5%, 7% and 0%.

Conclusions

In this study, clinical variables provided prognostic indicators of survival in NPC patients with lung metastases. Risk subsets would help in a more accurate assessment of a patient's prognosis in the clinical setting and could facilitate the establishment of patient-tailored medical strategies and supports.

Factors determining the survival of nasopharyngeal carcinoma with lung metastasis alone: does combined modality treatment benefit?

Background

Nasopharyngeal carcinoma (NPC) with lung metastasis alone has been reported as a relatively favorable prognostic group, and combined modality treatment might be indicated for selected cases. However, the prognostic factors determining survival of this group and the indication of combined therapy have not been thoroughly studied.

Methods

We retrospectively reviewed 246 patients of NPC with lung metastasis(es) alone presented at diagnosis or as the first failure after primary treatment from 1993 to 2008 in an academic tertiary hospital. Univariate and multivariate survival analyses of post-metastasis survival (PMS) and overall survival (OS) were carried out to determine the prognostic factors.

Results

The 3-year, 5-year, and 10-year of PMS and OS for the whole cohort were 34.3%, 17.0%, 8.6% and 67.8%, 45.4%, 18.5%, respectively. The median PMS (45.6 months vs. 23.7 months) and OS (73.7 months vs. 46.2 months) of patients treated with combined therapy was significantly longer than that of those treated with chemotherapy alone (P < 0.001). Age, disease-free interval (DFI) and treatment modality were evaluated as independent prognostic factors of OS, while only age and treatment modality retain their independent significance in PMS analysis. In stratified survival analysis, compared to chemotherapy alone, combined therapy could benefit the patients with DFI > 1 year, but not those with DFI ≤ 1 year.

Conclusions

Age ≤ 45 years, DFI > 1 year, and the combined therapy were good prognostic factors for NPC patients with lung metastasis(es) alone. The combination of local therapy and the basic chemotherapy should be considered for these patients with DFI > 1 year.

Risk subset of the survival for nasopharyngeal carcinoma patients with bone metastases: who will benefit from combined treatment?

Bone metastasis from nasopharyngeal carcinoma (NPC) is the most frequent type of distant metastasis (DM). The purpose of this study was to elucidate survival, prognostic factors, and significant of treatment in NPC patients with bone metastasis. A total of 221 patients who developed single type of DM from NPC at the first failure after primary treatment were retrospectively recruited from January 1998 to October 2000. The correlation between disease-free interval (DFI) and clinicopathologic features was assessed by the Chi-square test. Univariate and multivariate analyses of clinicopathologic variables were performed using Cox proportional hazards regression models. Actuarial survival rates were plotted against time using the Kaplan-Meier method, and log-rank testing was used to compare the differences between the curves. The median overall survival (OS) of the whole cohort and bone metastatic NPC patients were 38.5 and 33.3months, respectively. After univariate and multivariate analyses of clinicopathologic variables, age, local recurrence, subsequent metastasis, DFI and treatment modality were independently significant prognostic factors. The outcomes of bone metastatic NPC patients in low- and high-risk subset were significantly different (49.5 vs. 19.4months, P<0.001). In stratified survival analysis, compared to chemotherapy alone, chemoradiotherapy (CRT) could benefit the patients in low-risk subset (P<0.001), but not those in high-risk subset (P=0.135). Our findings indicated that clinicopathologic variables could provide easily available prognostic factors for survival in NPC patients with bone metastasis. A subset of bone metastatic NPC patients would benefit from aggressive combined treatment and receive a long-term survival.

Plasma EBV DNA clearance rate as a novel prognostic marker for metastatic/recurrent nasopharyngeal carcinoma

PURPOSE

To investigate the prognostic effect of the concentrations and clearance rates of plasma EBV DNA in metastatic/recurrent nasopharyngeal carcinoma (NPC).

EXPERIMENTAL DESIGN

Thirty relapsed and four previously nontreated metastatic NPC patients were treated according to the consensus guidelines of the head and neck cancer team in our hospital (i.v. chemotherapy first, followed by local irradiation boost and oral maintenance chemotherapy where applicable). Multiple plasma samples were collected during the first month of chemotherapy. Circulating EBV DNA concentrations were measured by a real-time quantitative PCR. The half-life values (t(1/2)) of plasma EBV DNA clearance were calculated. The associations between clinical outcome and plasma EBV DNA assays were analyzed.

RESULTS

Tumor response evaluated after 12 weeks of treatment showed 14 complete responses (41.2%), 12 partial responses (35.3%), 7 stable diseases (20.6%), and 1 progression disease (2.9%). The plasma EBV DNA concentrations have no significant effects on outcome prediction. The t(1/2) of plasma EBV DNA clearance ranged from 1.85 to 28.29 days (median, 3.99). Patients with a short t(1/2) of plasma EBV DNA clearance have significantly higher complete response rate and overall survival than those with long t(1/2). Multivariate analysis revealed a significant effect of the t(1/2) of plasma EBV DNA clearance on survival.

CONCLUSIONS

The clearance rates of plasma EBV DNA during the first month of chemotherapy can predict tumor response and patient survival. Early change of chemotherapy regimen may be considered for patients with slow plasma EBV DNA clearance rate.