Characteristic And Novel Therapeutic Strategies Of Nasopharyngeal Carcinoma With Synchronous Metastasis

Regulatory role of miRNAs in nasopharyngeal cancer involving PTEN/PI3K/AKT, TGFβ/SMAD, RAS/MAPK, Wnt/β-catenin and pRB-E2F signaling pathways: A review

MicroRNAs (miRNA) are small and conserved noncoding RNA molecules that regulate gene expression at the posttranscriptional level. These groups of RNAs are crucial in various cellular processes, especially in mediating disease pathogenesis, particularly cancer. The dysregulation of miRNAs was reported in many cancer types, including nasopharyngeal cancer (NPC), which is a malignant tumor of the nasopharynx. In this review, miRNAs involvement in crucial signaling pathways associated with NPC such as PTEN/PI3K/AKT, TGFβ/SMAD, RAS/MAPK, Wnt/β-catenin and pRB-E2F was investigated. miRNAs could function as tumor suppressor-miR or onco-miR in NPC profoundly influenced cell cycle, apoptosis, proliferation, migration, and metastasis. This comprehensive review of current literature provided a thorough profile of miRNAs and their interplay with the aforementioned signaling pathways in NPC. Understanding these molecular interactions could remarkably impact the diagnosis, prognosis, and therapeutic strategies for NPC.

IGF-1R mediates crosstalk between nasopharyngeal carcinoma cells and osteoclasts and promotes tumor bone metastasis

BACKGROUND

Nasopharyngeal carcinoma (NPC) poses a significant health burden in specific regions of Asia, and some of NPC patients have bone metastases at the time of initial diagnosis. Bone metastasis can cause pathologic fractures and pain, reducing patients' quality of life, and is associated with worse survival. This study aims to unravel the complex role of insulin-like growth factor 1 receptor (IGF-1R) in NPC bone metastasis, offering insights into potential therapeutic targets.

METHODS

We assessed IGF-1R expression in NPC cells and explored its correlation with bone metastasis. Experiments investigated the impact of osteoclast-secreted IGF-1 on the IGF-1R/AKT/S6 pathway in promoting NPC cell proliferation within the bone marrow. Additionally, the reciprocal influence of tumor-secreted Granulocyte-macrophage colony-stimulating factor (GM-CSF) on osteoclast differentiation and bone resorption was examined. The effects of IGF-1 neutralizing antibody, IGF-1R specific inhibitor (NVP-AEW541) and mTORC inhibitor (rapamycin) on nasopharyngeal carcinoma bone metastasis were also explored in animal experiments.

RESULTS

Elevated IGF-1R expression in NPC cells correlated with an increased tendency for bone metastasis. IGF-1, secreted by osteoclasts, activated the IGF-1R/AKT/S6 pathway, promoting NPC cell proliferation in the bone marrow. Tumor-secreted GM-CSF further stimulated osteoclast differentiation, exacerbating bone resorption. The IGF-1 neutralizing antibody, NVP-AEW541 and rapamycin were respectively effective in slowing down the rate of bone metastasis and reducing bone destruction.

CONCLUSION

The intricate interplay among IGF-1R, IGF-1, and GM-CSF highlights potential therapeutic targets for precise control of NPC bone metastasis, providing valuable insights for developing targeted interventions.

Nasopharyngeal carcinoma with synchronous breast metastasis: A case report

BACKGROUND

Recent reports have described cases of metachronous breast metastasis in patients with nasopharyngeal carcinoma. However, no similar cases of synchronous breast metastasis have been reported, and evidence that can be used to support the clinical diagnosis of stage IV nasopharyngeal carcinoma in patients with concurrent breast metastasis remains lacking. Therefore, additional evidence is required to elucidate the clinical characteristics of this condition and aid in the development of optimal management strategies.

CASE SUMMARY

We report the case of a 46-year-old woman who visited our hospital with a right breast mass as the first symptom. The first pathological biopsy report suggested triple-negative breast invasive carcinoma. Subsequent imaging revealed a nasopharyngeal mass. Further puncture biopsy of the nasopharyngeal mass, molecular pathological Epstein-Barr virus in situ hybridization, and immunohistochemistry confirmed the diagnosis of nasopharyngeal carcinoma with breast metastasis. The patient did not undergo a mastectomy and achieved complete remission after chemotherapy and radiotherapy. She continued to receive oral chemotherapy as maintenance therapy and experienced no recurrence or metastasis during the 6-month follow-up period.

CONCLUSION

This case report suggests that breast specialists should carefully rule out secondary breast cancers when diagnosing and treating breast masses. Furthermore, clinicians should aim to identify the pathological type of the tumor to obtain the most accurate diagnosis and prevent excessive diagnosis and treatment.

Construction of a fecal immune-related protein-based biomarker panel for colorectal cancer diagnosis: a multicenter study

Purpose

To explore fecal immune-related proteins that can be used for colorectal cancer (CRC) diagnosis.

Patients and methods

Three independent cohorts were used in present study. In the discovery cohort, which included 14 CRC patients and 6 healthy controls (HCs), label-free proteomics was applied to identify immune-related proteins in stool that could be used for CRC diagnosis. Exploring potential links between gut microbes and immune-related proteins by 16S rRNA sequencing. The abundance of fecal immune-associated proteins was verified by ELISA in two independent validation cohorts and a biomarker panel was constructed that could be used for CRC diagnosis. The validation cohort I included 192 CRC patients and 151 HCs from 6 different hospitals. The validation cohort II included 141 CRC patients, 82 colorectal adenoma (CRA) patients, and 87 HCs from another hospital. Finally, the expression of biomarkers in cancer tissues was verified by immunohistochemistry (IHC).

Results

In the discovery study, 436 plausible fecal proteins were identified. And among 67 differential fecal proteins (|log2 fold change| > 1, P< 0.01) that could be used for CRC diagnosis, 16 immune-related proteins with diagnostic value were identified. The 16S rRNA sequencing results showed a positive correlation between immune-related proteins and the abundance of oncogenic bacteria. In the validation cohort I, a biomarker panel consisting of five fecal immune-related proteins (CAT, LTF, MMP9, RBP4, and SERPINA3) was constructed based on the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression. The biomarker panel was found to be superior to hemoglobin in the diagnosis of CRC in both validation cohort I and validation cohort II. The IHC result showed that protein expression levels of these five immune-related proteins were significantly higher in CRC tissue than in normal colorectal tissue.

Conclusion

A novel biomarker panel consisting of fecal immune-related proteins can be used for the diagnosis of CRC.

Platelet-derived extracellular vesicles inhibit ferroptosis and promote distant metastasis of nasopharyngeal carcinoma by upregulating ITGB3

Nasopharyngeal carcinoma (NPC) is a malignancy with high metastatic and invasive nature. Distant metastasis contributes substantially to treatment failure and mortality in NPC. Platelets are versatile blood cells and the number of platelets is positively associated with the distant metastasis of tumor cells. However, the role and underlying mechanism of platelets responsible for the metastasis of NPC cells remain unclear. Here we found that the distant metastasis of NPC patients was positively correlated with the expression levels of integrin β3 (ITGB3) in platelet-derived extracellular vesicles (EVs) from NPC patients (P-EVs). We further revealed that EVs transfer occurred from platelets to NPC cells, mediating cell-cell communication and inducing the metastasis of NPC cells by upregulating ITGB3 expression. Mechanistically, P-EVs-upregulated ITGB3 increased SLC7A11 expression by enhancing protein stability and activating the MAPK/ERK/ATF4/Nrf2 axis, which suppressed ferroptosis, thereby facilitating the metastasis of NPC cells. NPC xenografts in mouse models further confirmed that P-EVs inhibited the ferroptosis of circulating NPC cells and promoted the distant metastasis of NPC cells. Thus, these findings elucidate a novel role of platelet-derived EVs in NPC metastasis, which not only improves our understanding of platelet-mediated tumor distant metastasis, but also has important implications in diagnosis and treatment of NPC.

Nasopharyngeal carcinoma: A new synthesis of literature data (Review)

Nasopharyngeal carcinoma (NPC) is an epithelial tumor, which develops most frequently from the lateral pharyngeal recess and holds some complex epidemiological characteristics. Its unusual race and geographic distribution suggests that not only the environmental factors are a contributing factor to the development of this rare cancer type, but also the genetic traits play an important role, along with nitrosamine-containing food consumption and Epstein-Barr virus infection. The signs and symptoms which a patient can present and suffer from are various and include nasal, otic, neurological as well as general ones; the way this tumor manifests being dependent on the stage of the tumor. The therapeutic management applicable in NPC needs to be established according to the case of the patient and include radiotherapy, chemotherapy, surgery, immune therapy, targeted therapy or combined treatment. The main objective of the treatment is local and regional tumor control; relapse is an important factor for future development of distant metastases. New therapeutic concepts are always sought of, current research focusing on precision medicine, meaning systemic treatment with a personalized radiotherapy approach according to the characteristics of the tumor.

Addition of chemoradiotherapy to palliative chemotherapy in de novo metastatic nasopharyngeal carcinoma: a real-world study

Background

To determine whether concurrent chemotherapy is necessary during locoregional radiotherapy (RT) after palliative chemotherapy (PCT) in patients with de novo metastatic nasopharyngeal carcinoma (mNPC).

Methods

A total of 746 patients with mNPC from 2000 to 2017 at our hospital were retrospectively reviewed. Among them, 355 patients received PCT followed by RT. Overall survival (OS) and progression-free survival (PFS), including locoregional progression-free survival (LRPFS) and distant progression-free survival (DPFS) were estimated with the Kaplan–Meier method and log-rank test. Cox proportional-hazards models, landmark analyses, propensity score matching, and subgroup analyses were used to address confounding.

Results

Of the patients included in our study, 192 received radiotherapy alone after PCT (PCT + RT), and 163 received concurrent chemoradiotherapy after PCT (PCT + CCRT). The prognosis of PCT + CCRT was significantly better than that of PCT + RT (5 year OS, 53.0 vs 36.2%; P = 0.004). After matching, the 5 year OS rates of the two groups were 55.7 and 39.0%, respectively (P = 0.034) and the median DPFS were 29.4 and 18.7 months, respectively (P = 0.052). Multivariate Cox regression analysis indicated that PCT + CCRT was an independent favorable prognostic factor (P = 0.009). In addition, conducting concurrent chemoradiotherapy after 4–6 cycles of PCT or conducting concurrent chemotherapy with single-agent platinum was associated with significant survival benefit in the matched cohort (5 year OS rate, 60.4 or 57.4%, respectively). The survival difference between groups remained significant when evaluating patients who survived for ≥ 1 year (P = 0.028).

Conclusions

The optimal treatment strategy of mNPC is the combination of PCT followed by concurrent chemoradiotherapy. More specifically, concurrent chemoradiotherapy with single-agent platinum after 4–6 cycles of PCT is suggested.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02464-7.

Prognostic value of EGFR and p-EGFR in nasopharyngeal carcinoma: A systematic review and meta-analysis

PURPOSE

To evaluate the prognostic effect and clinical significance of epidermal growth factor receptor and its phosphorlated form (EGFR/p-EGFR) in nasopharyngeal carcinoma.

METHODS

A systematic review and meta-analysis was designed. We visited PubMed, Embase, China National Knowledge Infrastructure Database, Database of Chinese sci-tech periodicals, WanFang Database, and China Biology Medicine disc to search for Chinese and English publications of prospective studies and retrospective studies investigating the association of EGFR/p-EGFR and nasopharyngeal carcinoma prognosis from inception to April 2021. The inclusion criteria were that the samples should be pathologically confirmed as nasopharyngeal carcinoma and the expression of EGFR/p-EGFR should be detected via immunohistochemistry; the study should analyze the prognostic significance of EGFR/p-EGFR in nasopharyngeal carcinoma; hazard ratio (HR) and 95% confidence interval (CI) should be reported in the study or could be derived from survival curves; and the outcomes of the study should include overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS).

RESULTS

A total of 18 studies evaluating 1451 samples were included. For studies that reported OS as an outcome, EGFR overexpression indicated worse OS of nasopharyngeal carcinoma patients. The heterogeneity between studies was high (I2 = 91%, P < .01), and a random-effect model was used to combine the effect size (HR = 1.71, 95% CI [1.21, 2.41], P < .01). Further sensitivity analysis and prespecified subgroup analysis were performed to detect the source of heterogeneity, and the results showed that the heterogeneity could not be eliminated. Publication bias assessed by funnel plots and Begg test and Egger test was low (Begg test: P = .846 and Egger test: P = .074). p-EGFR was not correlated with the OS of nasopharyngeal carcinoma patients (HR = 1.01, 95% CI [0.88, 1.15], P = .92). For studies that reported DFS, EGFR overexpression was associated with worse DFS in patients with nasopharyngeal carcinoma (HR = 2.53, 95% CI [1.84, 3.47], P < .01). For studies that reported PFS, EGFR overexpression was not correlated with the PFS of nasopharyngeal carcinoma patients (HR = 1.86, 95% CI [0.90, 3.82], P = .09). For studies that reported DMFS, EGFR overexpression was not correlated with the DMFS of nasopharyngeal carcinoma patients, and high heterogeneity between studies was detected (I2 = 97%, P < .01). A random-effect model was used to combine the effect size (HR = 1.80, 95% CI [0.56, 5.76], P = .32). A sensitivity analysis was conducted. Publication bias was detected to be low (Begg test: P = .817 and Egger test: P = .954). There was no correlation between p-EGFR overexpression and DMFS in patients with nasopharyngeal carcinoma (HR = 1.20, 95% CI [0.95, 1.52], P = .12).

CONCLUSION

In nasopharyngeal carcinoma patients, EGFR overexpression could be used as a biomarker that predicts poor OS and DFS, but not a prognostic biomarker for PFS and DMFS. The overexpression of p-EGFR was not shown to be associated with the prognosis of nasopharyngeal carcinoma patients and could not be used as a prognostic biomarker.

ETHICS AND DISSEMINATION

This study was registered on the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY), and reported as stated by the Preferred Reporting Items for Systematic reviews and Meta-Analyses. Neither ethical approval nor informed consent was required since this study was conducted based on previous publications.

INPLASY REGISTRATION NUMBER

INPLASY 202150010.

The Role of Genetic Pathways in the Development of Chemoradiation Resistance in Nasopharyngeal Carcinoma (NPC) Patients

Management of nasopharyngeal carcinoma (NPC) remains elusive despite new developments and advancement that has been made in the current management approaches. A patient’s survival and prognosis remain dismal especially for a late-stage disease. This is highly attribute to the chemoradiation resistance. Arrays of genes and molecular mechanisms underlie the development of chemoradiation resistance in NPC. Imperatively, unravelling the true pathogenesis of chemoradiation resistance is crucial as these significant proteins and genes can be modulated to produce an effective therapeutic target. It is pivotal to identify the chemoradiation resistance at the very beginning in order to combat the chemoradiation resistance efficiently. Intense research in the genetic ecosphere is critical, as the discovery and development of novel therapeutic targets can be used for screening, diagnosis, and treating the chemoradiation resistance aggressively. This will escalate the management trajectory of NPC patients. This article highlights the significance of genetic and molecular factors that play critical roles in the chemoradiation resistance and how these factors may be modified for next-generation targeted therapy products.

High-throughput chromosome conformation capture-based analysis of higher-order chromatin structure in nasopharyngeal carcinoma

Background

Firstly, we aimed to compare the differences of higher-order chromatin structure between nasopharyngeal carcinoma (NPC) and normal nasopharyngeal tissues. The second objective was to analyze the specific chromatin interaction site of NPC and the NPC-related genes regulated by this interaction site.

Methods

We included 6 NPC patients and 6 healthy controls to obtain the sequencing results of highest-throughput chromosome conformation capture (Hi-C) technique, followed by further analysis of the specific chromatin interaction sites in NPC.

Results

We found an abnormal ultra-long distance interaction site on the chromosome 7p in the CNE210 sample, which was caused by a fusion gene SEPT7P2-PSPH. Additionally, a significant interaction site between chromosome 8q and 3p was revealed in the samples CNE25, CNE29, and CNE211, which was the interaction between 1.5 kb downstream of ASAP1 and 0.8 kb upstream of CTNNB1 gene. Further quantitative polymerase chain reaction (qPCR) revealed that ASAP1 and CTNNB1 genes were more highly expressed in CNE25, CNE29, and CNE211 than in the Np group, preliminarily indicating that this interaction site was likely related to the high expression of ASAP1 and CTNNB1 in NPC.

Conclusions

Through Hi-C analysis, we analyzed the specific chromatin interaction sites associated with NPC, and found the chromosomal translocation and chromatin interaction sites associated with NPC based on statistical analysis. This study has certain guiding significance for in-depth study of the mechanism of NPC occurrence and development.

Optimal management of oligometastatic nasopharyngeal carcinoma

PURPOSE

Oligometastatic nasopharyngeal carcinoma (NPC) is a distinctive subset of metastatic NPC. Imaging examinations and biomarkers can screen out NPC patients with limited number of sites showing metastasis. Past studies have demonstrated the survival advantages of oligometastatic NPC over multiple metastatic NPC. The treatment strategies of de-novo oligometastatic NPC differ owing to the heterogeneity of this disease. This study aims to systematically review the characteristics and treatments of oligometastatic NPC.

METHODS

PubMed, EMBASE, the Web of Science, and the Cochrane Library were used to search for publications with an emphasis on oligometastatic NPC.

RESULTS

We have presented the current advances on the management of oligometastatic NPC, including the definition, diagnosis, biomarkers, classification, prognosis, subtype, especially systematic therapy, locoregional radiotherapy to the primary tumor, and treatments of the metastatic lesions.

CONCLUSIONS

More well-designed prospective clinical trials that are exclusive for oligometastatic NPC are warranted to determine the best treatment paradigm.

Induction Chemotherapy Combined With Intensity-Modulated Radiotherapy for 129 Nasopharyngeal Carcinoma Patients With Synchronous Metastases: A Retrospective Study

Objective

To analyze the therapeutic effect and prognostic factors of nasopharyngeal carcinoma (NPC) patients with distant metastases at initial diagnosis receiving induction chemotherapy with intensity-modulated radiotherapy (IMRT).

Methods

A total of 129 patients who underwent platinum-based induction chemotherapy followed by definitive IMRT with or without concurrent or adjuvant chemotherapy for newly diagnosed distant metastatic NPC in our center between March 2008 and November 2018 were retrospectively analyzed. 41 patients underwent local therapy for metastatic sites. Kaplan-Meier method was used to estimate survival rates, Log-rank test and Cox proportional hazards model were used to figure out independent prognostic factors of overall survival (OS).

Results

A total of 66 patients had been dead (median follow-up time, 51.5 months). The median overall survival (OS) time was 54.2 months (range, 7-136 months), and the 1-year, 2-year, 3-year, 5-year overall survival rates were 88.0%,71.0%,58.0%, and 47.0%. Multivariate analysis found that the factors correlated with poor overall survival were pre-treatment serum lactate dehydrogenase (SLDH) >180U/L, chemotherapy cycles<4, and M1 stage subdivision (M1b, single hepatic metastasis and/or multiple metastases excluding the liver; and M1c, multiple hepatic metastases). The 5-year OS rates for M1a, M1b and M1c were 62.6%,40.4% and 0%, respectively.

Conclusion

Platinum-containing induction chemotherapy combined with IMRT seemed to be advantageous to prolong survival for some NPC patients with synchronous metastases at initial diagnosis. The independent factors to prognosticate OS were pre-treatment SLDH, number of chemotherapy cycles, and M1 subcategories. Prospective clinical trials are needed to confirm the result.

Lactate dehydrogenase kinetics predict chemotherapy response in recurrent metastatic nasopharyngeal carcinoma

Background:

Lactate dehydrogenase (LDH) is a known prognostic biomarker for the endemic variant of nasopharyngeal carcinoma (NPC). Here, we investigate whether serial changes in LDH level between chemotherapy (CT) cycles are associated with tumour response to CT.

Methods:

Patients with biopsy-proven, recurrent or treatment-naïve metastatic NPC (mNPC) were recruited. All patients had received at least two cycles of platinum-based doublet or triplet CT, with serial assessment of LDH prior to every cycle of chemotherapy (CT1–6). Patients harbouring conditions that affect LDH levels (IU/L) were excluded. Tumour response was assessed after every two cycles of CT by RECIST v1.1.

Results:

A total of 158 patients were analysed, including 77 with recurrent and 81 with treatment-naïve mNPC. High pre-CT LDH was associated with an inferior overall survival [hazard ratio 1.93 for ⩾240 versus <240 (1.34–2.77), p < 0.001], which is consistent with published literature. We found that both absolute LDH levels and LDH ratios (LDH_CTn: LDH_CTn–1) were associated with tumour response [partial response versus progressive disease: median value across CT1–6 = 168–190 versus 222–398 (absolute); 0.738–0.988 versus 1.039–1.406 (ratio)], albeit LDH ratio had a tighter variance between patients. Finally, we showed that an LDH ratio cut-off of 1.0 at CT1, CT3 and CT5 was predictive of progressive disease at CT2, CT4, CT6 [area under the curve of 0.73 (0.65–0.80)].

Conclusion:

Herein, we characterised the longitudinal variation of LDH in response to CT in mNPC. Our findings suggest the potential utility of interval LDH ratio to predict subsequent tumour response to CT.

Synchronous Metastatic Nasopharyngeal Carcinoma: Characteristics and Survival of Patients Adding Definitive Nasopharyngeal-Neck Radiotherapy to Systematic Chemotherapy

Purpose

To determine the M1 sub-staging in synchronous metastatic nasopharyngeal carcinoma (smNPC) and to examine the effect of nasopharyngeal-neck radiotherapy (RT) and local treatment of metastases on overall survival (OS) of smNPC patients.

Patients and Methods

A total of 150 patients with smNPC were included. Metastatic characteristics associated with their potential prognostic significance were analyzed. Then, a stratification system of the M1 sub-staging in smNPC was provided according to metastatic features. Moreover, the OS of patients with or without nasopharyngeal-neck RT was compared by Log rank test. The OS of patients who received or did not receive local treatment of metastases was also analyzed.

Results

We successfully divided the M1 stage into three sub-staging: M1a (a single site with a single lesion), M1b (a single site with multiple lesions), and M1c (multiple sites with multiple lesions). The median OS was 53.2, 25.8, and 18.9 months for M1a, M1b, and M1c, respectively (p < 0.001). Nasopharyngeal-neck RT plus systematic chemotherapy (CT) significantly improved OS compared to systematic CT (median OS, 34.0 vs 15.2 months, p = 0.002). However, incorporation of local treatment of metastases did not bring survival benefit to smNPC patients who received nasopharyngeal-neck RT plus systematic CT (median OS, 25.8 vs 35.1 months, p = 0.374).

Conclusion

The sub-staging of the M1 stage in smNPC had promising prognostic value. Adding nasopharyngeal-neck RT on the basis of systematic CT markedly improved the survival of smNPC patients, while addition of local treatment of metastases to nasopharyngeal-neck RT plus systematic CT for smNPC needed further exploration.

Epstein-Barr Virus Mediated Signaling in Nasopharyngeal Carcinoma Carcinogenesis

Simple Summary

Epstein-Barr virus (EBV) infection is known to contribute in nasopharyngeal carcinoma (NPC) carcinogenesis. The oncogenic roles of the EBV proteins and non-coding RNAs in NPC are becoming evident with the aid of current advances in genome-wide and in-depth molecular analyses. This current work provides a comprehensive overview, which covers recent understandings of the pathogenic role of EBV infection in NPC. Perspectives on molecular mechanisms, which are involved in the pathogenesis of NPC, focusing on the connection between EBV and NPC cells and the corresponding signaling pathways are highlighted. Cancer hallmarks associated with EBV in NPC development are also discussed herein.

Abstract

Nasopharyngeal carcinoma (NPC) is one of the most common tumors occurring in China and Southeast Asia. Etiology of NPC seems to be complex and involves many determinants, one of which is Epstein-Barr virus (EBV) infection. Although evidence demonstrates that EBV infection plays a key role in NPC carcinogenesis, the exact relationship between EBV and dysregulation of signaling pathways in NPC needs to be clarified. This review focuses on the interplay between EBV and NPC cells and the corresponding signaling pathways, which are modulated by EBV oncoproteins and non-coding RNAs. These altered signaling pathways could be critical for the initiation and progression of NPC.

Pattern and prognosis of distant metastases in nasopharyngeal carcinoma: A large-population retrospective analysis

Currently, the features and prognosis of nasopharyngeal carcinoma (NPC) with distant metastases are still rarely reported. Thus, the main purpose of our study was to investigate the metastasis patterns of different histological types of NPC and to clarify the prognostic characteristics of metastases at different sites. Patients were enrolled from the SEER program from 2010 to 2016. Chi‐squared tests were used to compare features between groups. The tendency to develop combined metastases was assessed with the odds ratio. The Kaplan‐Meier method was used for the survival analysis. Univariate and multivariate Cox analyses were used to select the independent prognostic risk factors for inclusion in the nomogram. In the present study, we found the following: (1) tumors are highly likely to metastasize if they have a larger volume, the regional lymph nodes are relatively large, or the regional lymph nodes are biopsied but not removed; (2) the bone and the brain were the most and least common metastatic sites among all histological types and N stages. Metastasis at two sites was the most common pattern, and bone metastasis was generally associated with metastasis to the liver or brain; (3) the prognostic analyses in metastatic patients showed that cancer‐specific survival (CSS) was relatively worse in patients with multiple metastases, and in those with liver metastasis regardless of the number of other metastatic sites; (4) A nomogram was constructed for clinical use based on four independent prognostic risk indicators, including histology, radiation therapy, chemotherapy, and metastatic status. Our findings provide a reference for clinical decision‐making and future diagnostic screening tests for NPC with distant metastases.

Raman profile alterations of irradiated human nasopharyngeal cancer cells detected with laser tweezer Raman spectroscopy

Radiotherapy has been widely used for nasopharyngeal carcinoma (NPC) treatment, which causes DNA damage and alterations of macromolecules of cancer cells. However, the Raman profile alterations of irradiated NPC cells remain unclear. In the present study, we used laser tweezers Raman spectroscopy (LTRS) to monitor internal structural changes and chemical modifications in NPC cells after exposure at a clinical dose (2.3 Gy) to X-ray irradiation (IR) at a single-cell level. Two types of NPC cell lines, CNE2 (EBV-negative cell line) and C666-1 (EBV-positive cell line), were used. The Raman spectra of cells before and after radiation treatment were recorded by LTRS. The analysis of spectral differences indicated that the IR caused Raman profile alterations of intracellular proteins, DNA base and lipids. Moreover, by using the multivariate statistical analysis including principal component analysis (PCA) and linear discriminant analysis (LDA) algorithm, an accuracy of 90.0% for classification between CNE2 cells before and after IR could be achieved, which was 10% better than that of C666-1 cells. The results demonstrated that CNE2 cells were more sensitive to IR in comparison to C666-1 cells, providing useful information for creating a treatment strategy in clinical practice. This exploratory study suggested that LTRS combined with multivariate statistical analysis would be a novel and effective tool for evaluating the radiotherapeutic effect on tumor cells, and for detection of the corresponding alterations at the molecular level.

Laser tweezer Raman spectroscopy combined with multivariate statistical analysis was used for evaluating the radiotherapeutic effect on a single tumor cell.