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BACKGROUND: Despite zinc finger and BTB domain-containing 7A (ZBTB7A) documented importance in multiple tumors, the function and clinical value in Colorectal cancer (CRC) remain elusive. The aim of this study was to evaluate the functional roles and the clinical value of ZBTB7A in CRC progression. METHODS: The level of ZBTB7A was detected in a large cohort of CRC patients (n = 189) by immunohistochemistry (IHC), and we analyzed the diagnostic and prognostic value of the protein. In addition, the functional roles of ZBTB7A on CRC were explored in vitro and in vivo. RESULTS: Survival analyses indicated that patients with high ZBTB7A expression made the prognosis worse (P = 0.024). Functionally, knockdown of ZBTB7A could markedly inhibit tumor proliferation in vitro and in vivo, whereas ZBTB7A overexpression displayed the opposite results. CONCLUSIONS: ZBTB7A was associated with poor survival outcomes and functioned as an oncogene in CRC patients, indicating that it is a potential prognostic biomarker and therapeutic target for CRC patients.
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Neoplasias Colorrectales , Proteínas de Unión al ADN , Factores de Transcripción , Línea Celular Tumoral , Neoplasias Colorrectales/genética , Proteínas de Unión al ADN/genética , Humanos , Oncogenes/genética , Pronóstico , Factores de Transcripción/genéticaRESUMEN
Background: Treatment options for patients with recurrent/metastatic nasopharyngeal carcinoma (RM-NPC) are not clear after progression on previous treatment with PD-(L)1 inhibitor; critical gaps in evidence remain for such cases. Immunotherapy combined with antiangiogenic therapy has been reported to have synergistic antitumor activity. Therefore, we evaluated the efficacy and safety of camrelizumab plus famitinib in patients with RM-NPC who failed treatment with PD-1 inhibitor-containing regimens. Methods: This multicenter, adaptive Simon minimax two-stage, phase II study enrolled patients with RM-NPC refractory to at least one line of systemic platinum-containing chemotherapy and anti-PD-(L)1 immunotherapy. The patient received camrelizumab 200 mg every 3 weeks and famitinib 20 mg once per day. The primary endpoint was objective response rate (ORR), and the study could be stopped early as criterion for efficacy was met (>5 responses). Key secondary endpoints included time to response (TTR), disease control rate (DCR), progression-free survival (PFS), duration of response (DoR), overall survival (OS), and safety. This trial was registered with ClinicalTrials.gov, NCT04346381. Findings: Between October 12, 2020, and December 6, 2021, a total of 18 patients were enrolled since six responses were observed. The ORR was 33.3% (90% CI, 15.6-55.4) and the DCR was 77.8% (90% CI, 56.1-92.0). The median TTR was 2.1 months, the median DoR was 4.2 months (90% CI, 3.0-not reach), and the median PFS was 7.2 months (90% CI, 4.4-13.3), with a median follow-up duration of 16.7 months. Treatment-related adverse events (TRAEs) of grade ≥3 were reported in eight (44.4%) patients, with the most common being decreased platelet count and/or neutropenia (n = 4, 22.2%). Treatment-related serious AEs occurred in six (33.3%) patients, and no deaths occurred due to TRAEs. Four patients developed grade ≥3 nasopharyngeal necrosis; two of them developed grade 3-4 major epistaxis, and they were cured by nasal packing and vascular embolization. Interpretation: Camrelizumab plus famitinib exhibited encouraging efficacy and tolerable safety profiles in patients with RM-NPC who failed frontline immunotherapy. Further studies are needed to confirm and expand these findings. Funding: Jiangsu Hengrui Pharmaceutical Co., Ltd.
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Early diagnosis and treatment is known to improve prognosis for nasopharyngeal carcinoma (NPC). The study determined the specific peptide profiles by comparing the serum differences between NPC patients and healthy controls, and provided the basis for the diagnostic model and identification of specific biomarkers of NPC. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) can be used to detect the molecular mass of peptides. Mass spectra of peptides were generated after extracting and purification of 40 NPC samples in the training set, 21 in the single center validation set and 99 in the multicenter validation set using weak cationic-exchanger magnetic beads. The spectra were analyzed statistically using FlexAnalysis™ and ClinProt™ bioinformatics software. The four most significant peaks were selected out to train a genetic algorithm model to diagnose NPC. The diagnostic sensitivity and specificity were 100% and 100% in the training set, 90.5% and 88.9% in the single center validation set, 91.9% and 83.3% in the multicenter validation set, and the false positive rate (FPR) and false negative rate (FNR) were obviously lower in the NPC group (FPR, 16.7%; FNR, 8.1%) than in the other cancer group (FPR, 39%; FNR, 61%), respectively. So, the diagnostic model including four peptides can be suitable for NPC but not for other cancers. FGA peptide fragments identified may serve as tumor-associated biomarkers for NPC.
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Biomarcadores de Tumor/sangre , Fibrinógeno/análisis , Neoplasias Nasofaríngeas/diagnóstico , Péptidos/sangre , Adulto , Secuencia de Aminoácidos , Carcinoma , Femenino , Humanos , Fenómenos Magnéticos , Nanopartículas de Magnetita , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Proteómica/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
Serum enzymes that play potential roles in tumor growth have recently been reported to have prognostic relevance in a diverse array of tumors. However, prognosis-related serum enzymes are rarely reported for nasopharyngeal carcinoma(NPC). To clarify whether the level of serum enzymes is linked to the prognosis of NPC, we reviewed the pretreatment data of lactate dehydrogenase(LDH), alkaline phosphatase (ALP), and glutamyl transferase (GGT) in 533 newly diagnosed NPC patients who underwent radical radiotherapy between May 2002 and October 2003 at Sun Yat-sen University Cancer Center. Patients were grouped according to the upper limit of normal values of LDH, ALP, and GGT. The Kaplan-Meier method and log-rank test were used for selecting prognostic factors from clinical characteristics and serum enzymes, and the chi-square test was applied to analyze the relationships of clinical characteristics and serum enzymes. Finally, a Cox proportional hazards model was used to identify the independent prognostic factors. We found that increased levels of LDH had poor effects on both overall survival and distant metastasis-free survival (P = 0.009 and 0.035, respectively), and increased pretreatment level of serum ALP had poor effects on both overall survival and local recurrence-free survival (P = 0.037 and 0.039, respectively). In multivariate analysis, increased LDH level was identified as an independent prognostic factor for overall survival. Therefore, we conclude that increased pretreatment serum LDH and ALP levels are poor prognostic factors for NPC.
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Fosfatasa Alcalina/sangre , L-Lactato Deshidrogenasa/sangre , Neoplasias Nasofaríngeas/sangre , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Niño , Cisplatino/administración & dosificación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/tratamiento farmacológico , Neoplasias Nasofaríngeas/patología , Neoplasias Nasofaríngeas/radioterapia , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia , Pronóstico , Modelos de Riesgos Proporcionales , Radioterapia Asistida por Computador , Radioterapia Conformacional , Radioterapia de Intensidad Modulada , Tasa de Supervivencia , Adulto Joven , gamma-Glutamiltransferasa/sangreRESUMEN
PURPOSE: To study the prevalence of nodal metastases in sinonasal adenoid cystic carcinoma (SNACC) and to evaluate whether prophylactic neck irradiation (PNI) should be performed in patients with clinical N0 (cN0) disease. PATIENTS AND METHODS: Between April 1992 and November 2020, 166 patients with SNACC who had undergone radiotherapy at our department were retrospectively analyzed. The median follow-up time was 71.3 months. RESULTS: Among 166 cases of SNACC, a total of 13 (7.8%) had retropharyngeal or cervical nodal metastasis and 93% (12/13) cases occurred in patients with advanced T stage (T3-T4). Levels VIIa, Ib, and IIa were the most common sites of initial nodal involvement. Only 1.2% (2/166) of patients presented late neck recurrence. Lymph node metastasis independently predicted a poor progression-free survival (PFS) (P = 0.017) but had no impact on overall survival (OS) (P = 0.38). PNI was performed on 36% (55/153) of cN0 patients. The OS (P = 0.42), PFS (P = 0.59), nodal recurrence-free survival (NRFS) (P = 0.46) and distant metastasis-free survival (DMFS) (P = 0.63) rates showed no significant difference between cases with and without PNI. Furthermore, cN0 patients with T4b (P = 0.53; P = 0.61), tumor origin from maxillary sinus (P = 0.55; P = 0.53) or nasopharynx involvement (P = 0.56; P = 0.60) showed no extended OS or PFS associated with PNI. CONCLUSIONS: Regardless of the T stage or the site of origin, prophylactic neck irradiation (PNI) for cN0 patients did not provide any benefit on OS and PFS, suggesting that its application on such patients is not warranted unless there is clinical suspicion.
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Carcinoma Adenoide Quístico , Carcinoma , Senos Paranasales , Carcinoma/patología , Carcinoma Adenoide Quístico/radioterapia , Humanos , Metástasis Linfática , Estadificación de Neoplasias , Senos Paranasales/patología , Estudios RetrospectivosRESUMEN
OBJECTIVE: The aim of the study was to investigate clinical evidence for defining the indications of prophylactic level IB radiotherapy (RT) in nasopharyngeal carcinoma (NPC). METHODS: We conducted a phase 2 prospective study in 116 newly diagnosed patients with NPC treated by intensity-modulated RT. Whether level IB was irradiated is based on the risk score model (RSM). Two groups based on RSM were obtained: low risk and high risk. Omission of level IB irradiation was conducted in the low-risk group, otherwise level IB was contoured as part of the treatment target. Grade 2 or worse xerostomia at 12 months was assessed by the European Organization for Research and Treatment of Cancer (EORTC) QLQ-H&N35 questionnaire. RESULTS: At a median follow-up of 16 months (range, 1-26 months), none of the patients developed failures at level IB. The 1-year overall survival, locoregional recurrence-free survival, and distant metastasis-free survival rates were 98.3%, 97.2%, and 95.8%, respectively. At 12 months xerostomia side-effects were reported in 90 of 116 alive patients; grade 2 or worse xerostomia at 12 months was significantly lower in the low-risk group than in the high-risk group. CONCLUSION: Omission of level IB irradiation was feasible for patients with low-risk IB lymph nodes metastasis.
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Carcinoma , Neoplasias Nasofaríngeas , Radioterapia de Intensidad Modulada , Xerostomía , Carcinoma/patología , Carcinoma/radioterapia , Humanos , Ganglios Linfáticos/patología , Carcinoma Nasofaríngeo/etiología , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/tratamiento farmacológico , Neoplasias Nasofaríngeas/radioterapia , Estudios Prospectivos , Radioterapia de Intensidad Modulada/efectos adversos , Factores de Riesgo , Xerostomía/etiología , Xerostomía/prevención & controlRESUMEN
[This corrects the article DOI: 10.3389/fonc.2020.605777.].
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Background: Radioresistance-induced local failure, which can result in residual or recurrent tumors, remains one of the major causes of treatment failure in nasopharyngeal carcinoma (NPC). Lipocalin 2 (LCN2) is known to play important roles in cancer initiation, progression, and treatment responses. However, its role in the radioresistance of NPC remains unclear. Methods: Microarray data from the Gene Expression Omnibus (GEO) was screened for candidate biomarkers relating to the radioresistance of NPC. The expression of LCN2 in NPC cell lines was verified by quantitative real-time PCR (RT-qPCR) and western blotting. The effects of knockdown or overexpression of LCN2 on NPC radiosensitivity were examined using a soft agar colony formation assay and a γH2AX assay. LCN2 expression in NPC specimens was evaluated by immunohistochemistry. Survival outcomes were analyzed. A possible correlation between LCN2 and hypoxia-inducible factor 1-alpha (HIF-1A) was examined by western blotting and a tissue microarray. Results: LCN2 was highly expressed in the radioresistant NPC cell line CNE2R. Knocking down LCN2 enhanced the radiosensitivity of NPC cells by impairing their ability to repair DNA damage or proliferate, while ectopic expression of LCN2 conferred additional radioresistance to NPC cells. Immunohistochemical analysis of 100 NPC specimens revealed that LCN2 expression was significantly upregulated in radioresistant NPC tissues and was associated with NPC recurrence. Furthermore, a significant correlation between the expression of LCN2 and HIF-1A was detected. Conclusion: LCN2 is associated with radioresistance and recurrence in NPC and may facilitate the development of a radioresistant phenotype through interacting with HIF-1A. Our data indicate that LCN2 is a promising target for predicting and overcoming radioresistance in NPC.
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OBJECTIVE: Postradiation nasopharyngeal necrosis (PRNN) is a notorious complication after radiotherapy that affects prognosis in patients with nasopharyngeal carcinoma (NPC). It is important for clinical doctors to realize this problem in order to cope with this severe clinical situation. The aim of our study was to assess the bacteriology of PRNN and to demonstrate the antimicrobial susceptibility pattern that should guide the clinicians towards more appropriate antibiotic use. METHODS: Sixty-nine NPC patients with PRNN in our department between March 2013 and December 2017 were retrospectively enrolled. Pathogenic culture and drug sensitivity test were performed in these 69 NPC patients with PRNN. The infection rate of Pathogens and the sensitivity of the drugs were analyzed based on these results. RESULTS: Sixty-nine NPC patients with PRNN were enrolled in our study. Pathogens were identified in 58 (84%) patients. Of the 58 patients, Staphylococcus aureus was isolated in 34 (58.6%) patients. And the second most common group of bacterial isolates was Pseudomonas aeruginosa. Antibiotic sensitivity showed that Levofloxacin was the highest (88.5%), followed by Ciprofloxacin (85.2%) and Gentamicin (80.3%). The only pathologic fungus was Candidaalbicans, about 6.8%. The positive rates of bacterial and fungal culture in PRNN patients were not significantly different from the patients' gender, age, stage, number of radiotherapy courses (P>0.05), but the cure rate was statistically higher in culture-negative patients in comparison with culture-positive patients (63.6% vs 20.7%, P=0.011). CONCLUSION: Our results provide an overall picture of the microbiology and drug susceptibility patterns for NPC patients with PRNN and could help implement guidelines for more rational treatment and improve therapeutic outcome.
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Antibacterianos/uso terapéutico , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Nasofaringe/efectos de la radiación , Traumatismos por Radiación/microbiología , Adulto , Anciano , Candida albicans/efectos de los fármacos , Ciprofloxacina/uso terapéutico , Femenino , Gentamicinas/uso terapéutico , Humanos , Levofloxacino/uso terapéutico , Masculino , Persona de Mediana Edad , Nasofaringe/diagnóstico por imagen , Nasofaringe/patología , Necrosis/diagnóstico por imagen , Necrosis/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Traumatismos por Radiación/diagnóstico por imagen , Traumatismos por Radiación/patología , Estudios Retrospectivos , Staphylococcus aureus/efectos de los fármacos , Resultado del TratamientoRESUMEN
PURPOSE: To analyze the outcomes and toxicities of induction chemotherapy (ICT) followed by concurrent chemoradiotherapy (CCRT) plus adjuvant chemotherapy (ACT) in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC). METHODS: Retrospective analysis of 163 patients with LA-NPC referred from August 2015 to December 2018 was carried out. All patients underwent platinum-based ICT followed by CCRT plus ACT. RESULTS: The median follow-up time was 40 months, ranging from 5 to 69 months. The 3-year disease-free survival (DFS), overall survival (OS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates were 80.8, 90.0, 91.6, and 87.4%, respectively. The most frequent acute grade 3/4 adverse events were leukopenia (66.8%), neutropenia (55.8%), mucositis (41.1%), thrombocytopenia (27.0%), and anemia (14.7%). CONCLUSION: ICT followed by CCRT plus ACT did not seemingly enhance DFS and OS in LA-NPC patients compared to the addition of ICT to CCRT (historical controls). In contrast, ICT followed by CCRT plus ACT had more acute adverse events than ICT followed by CCRT. Longer-term clinical studies are required to examine the treatment outcomes and late toxicities.
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Bone metastasis is the most frequent type of distant metastasis in nasopharyngeal carcinoma (NPC). In this study, we investigated the correlation between the skull base bone destruction and the distant bone metastasis in patients with NPC. A total of 449 cases with NPC who were diagnosed and had definitive radiotherapy from 2001 to 2006 were enrolled in this study. The skull base bone destruction was diagnosed by computed tomography (CT) in all cases, and 191 patients also underwent magnetic resonance imaging scan. Kaplan-Meier method was adopted to perform the univariate analysis; Cox regression model was used to perform multivariate analysis to determine whether the skull base bone destruction when diagnosed by CT was an independent impact factor of the distant bone metastases. The group with skull base bone destruction had a distant bone metastases rate of 9.0% (14/155), whereas the group without skull base bone destruction had rate of 4.1% (12/294). The multivariate analysis showed that the skull base bone destruction, when diagnosed by CT, was an independent impact factor of the distant bone metastases-free survival in the early N-staging cases, but was not an independent impact factor when diagnosed by MRI. The skull base bone destruction diagnosed by CT in patients with NPC had predictive value for the distant bone metastases, especially for the early N-staging cases.
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BACKGROUND: With the improved overall survival (OS) of nasopharyngeal carcinoma (NPC) patients, the importance of quality of life (QoL) is increasingly being recognized. For some radiosensitive NPC patients, whether low-dose radiotherapy can improve the QoL without affecting clinical efficacy is unknown. This study aimed to assess the survival rates and QoL of NPC patients treated with 50 Gy radiotherapy plus hematoporphyrin derivative (HPD). METHODS: Forty-six newly diagnosed NPC patients treated with 50 Gy radiotherapy plus HPD between June 1988 and July 1992 were analyzed. All patients were restaged according to the 7th edition of the American Joint Committee on Cancer staging system. The radiotherapy plan was designed on the basis of pretreatment computed tomography. The OS, local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) rates were estimated using the Kaplan-Meier method. QoL was assessed using the Late Radiation Morbidity Scoring Criteria of the Radiation Therapy Oncology Group. RESULTS: The 5-year OS, LRFS, DMFS, and DFS rates were 74.3%, 72.6%, 82.1%, and 61.2%, respectively. The corresponding 10-year rates were 38.4%, 62.9%, 78.5%, and 49.8%, respectively, and the 20-year rates were 27.7%, 51.4%, 78.5%, and 40.7%, respectively. None of the patients developed severe radiation-related complications, such as radiation-induced temporal lobe necrosis, hearing loss, trismus, and dysphagia. CONCLUSION: Some NPC patients were sensitive to 50 Gy radiotherapy plus HPD, and this sensitivity was characterized by long-term survival without significant late treatment morbidities.
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Hematoporfirinas/uso terapéutico , Neoplasias Nasofaríngeas/tratamiento farmacológico , Neoplasias Nasofaríngeas/radioterapia , Adulto , Anciano , Carcinoma , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Calidad de Vida , Dosificación Radioterapéutica , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
Abnormal interaction between non-coding RNAs has been demonstrated to be a common molecular event in various human cancers, but its significance and underlying mechanisms have not been well documented. RNA-binding proteins (RBPs) are key regulators of RNA transcription and post-transcriptional processing. In this study, we found that RNA-binding protein 24 (RBM24) was frequently downregulated in nasopharyngeal carcinoma (NPC). The restoration of RBM24 expression suppressed NPC cellular proliferation, migration and invasion and impeded metastatic colonization in mouse models. Microarray analyses revealed that miR-25 expression was upregulated by RBM24 expression in NPC cells. Similarly, ectopic miR-25 expression suppressed NPC cellular growth and motility by targeting the pro-oncogenic lncRNA MALAT1, and the knockdown of MALAT1 expression exhibited similar effects as RBM24 restoration in NPC cells. Overall, these findings suggest a novel role of RBM24 as a tumor suppressor. Mechanistically, RBM24 acts at least in part through upregulating the expression of miR-25, which in turn targets MALAT1 for degradation.
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Carcinoma/genética , Carcinoma/patología , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , MicroARNs/metabolismo , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patología , ARN Largo no Codificante/genética , Proteínas de Unión al ARN/metabolismo , Regulación hacia Arriba/genética , Animales , Secuencia de Bases , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Regulación hacia Abajo/genética , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Ratones Endogámicos BALB C , Ratones Desnudos , MicroARNs/genética , Carcinoma Nasofaríngeo , Invasividad Neoplásica , Metástasis de la NeoplasiaRESUMEN
BACKGROUND: The purpose of this study was to investigate the relationship between pretreatment nutritional status and prognosis of nasopharyngeal carcinoma (NPC). METHODS: Pretreatment nutritional status was evaluated by ideal body weight percentile (IBW%) and serum albumin for 512 patients with NPC who underwent radical radiotherapy. Kaplan-Meier methods, log-rank test, and a Cox model were applied for survival analysis. RESULTS: Before radiotherapy, IBW% <90% was related to poorer overall survival (OS) and distant metastasis-free survival (DMFS; p = .031 and p = .012, respectively); albumin ≤43.0 g/L was related to poorer OS and DMFS (p < .001 and p = .042, respectively); both IBW% and albumin were independent prognostic factors for OS; those patients with IBW% <90% and albumin ≤43.0 g/L simultaneously had the worst OS and DMFS. CONCLUSION: Decrease of pretreatment IBW% and albumin was related to poorer survival of NPC.
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Peso Corporal Ideal/fisiología , Neoplasias Nasofaríngeas/mortalidad , Neoplasias Nasofaríngeas/radioterapia , Albúmina Sérica/análisis , Adulto , Carcinoma , Estudios de Cohortes , Intervalos de Confianza , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patología , Invasividad Neoplásica/patología , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Estado Nutricional , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Curva ROC , Medición de Riesgo , Estadísticas no Paramétricas , Tasa de Supervivencia , Factores de Tiempo , Resultado del TratamientoRESUMEN
The purpose of the present study was to investigate alternative endpoints to the 5-year overall survival (OS) and locoregional control (LRC) for nasopharyngeal carcinoma (NPC). A total of 2,450 NPC patients were enrolled in this study, including 1,842 patients treated with two-dimensional (2D) radiotherapy (RT), 451 treated with 3D conformal RT (CRT) and 157 treated with intensity-modulated RT (IMRT). We sequentially calculated the 1-, 2-, 3- and 4-year survival rates using a life table and compared these with the 5-year survival rate using the McNemar method, with the survival rate of the last indifferent comparison being considered as the alternative endpoint. For 2D RT, stage I patients exhibited similar survival rates at 1 and 5 years (98.9 vs. 94.4%, respectively; P=0.125 for both OS and LRC); stage N3 patients exhibited similar 4-year OS (55.2 vs. 53.5%; P=1.000) and 2-year LRC (78.3 vs. 71.2%; P=0.125) to the 5-year OS and LRC. For IMRT, the 1-, 2-, 3-, 4- and 5-year OS and LRC rates in stage I/II NPC patients were 100, 98, 96, 94 and 94% for OS and 100, 98, 96, 96 and 96% for LRC, respectively. No significant differences were observed for all the comparisons. For stage III/IV NPC patients treated with IMRT, the 1-, 2-, 3-, 4- and 5-year rates were 99.1, 96.3, 92.5, 88.8 and 85.0% for OS and 98.1, 97.2, 95.3, 90.7 and 89.7% for LRC, respectively. Only the 4-year OS and LRC rates were indifferent from those at 5 years (P=0.125 for OS and P=1.00 for LRC). In conclusion, the 1-year OS and LRC for stage I NPC patients treated with 2D RT or stage I/II NPC patients treated with IMRT, the 4-year OS and 2-year LRC for stage N3 NPC patients treated with 2D RT and the 4-year OS and LRC for stage III/IV NPC patients treated with IMRT were determined as the alternative endpoints to the 5-year OS and LRC for NPC patients.
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Bmi-1, a member of the polycomb family, it is involved in self renewal of stem cells and functions as an oncogene in many malignant human cancer types. Recent studies have demonstrated that Bmi-1 is a predictive factor for poor patient prognosis. However, the underlying mechanisms of radioresistance mediated by Bmi-1 are poorly understood. In this study, the dose-survival relationship was analyzed using a clonogenic survival assay and combined radiation treatment with Bmi-1 overexpression or silencing. DNA double-strand break (DSB) and repair was assessed by immunofluorescence staining of γH2AX foci. In addition, mitochondrial membrane potential was detected between Bmi-1 knockdown and control MCF-7 cells after irradiation. Apoptosis and cell cycle were evaluated by flow cytometry. We found that exposure of MCF-7 cells overexpressing Bmi-1 to ionizing radiation resulted in dramatically enhanced survival relative to control cells, whereas cells with silenced Bmi-1 showed markedly reduced survival. Bmi-1 inhibition significantly increased DSBs and decreased DSB repair. Furthermore, Bmi-1 knockdown induced loss of mitochondrial membrane potential and enhanced apoptosis by up-regulating p53, p21, Bax expression and down-regulating p-AKT and Bcl-2 expression. These results indicate that Bmi-1 may play an important role in radiosensitivity, and the suppression of its expression might be a potential therapeutic target for breast cancer.