No abstract

IMRT for NPC patients achieved excellent long-term locoregional control (LRC) and OS, with acceptable acute and late toxicities. After the treatment, xerostomia was improved over time. Distant metastasis remained the main cause of failure. More effective systemic therapy is demanding for reducing the risk of distant metastasis.

PurposeTo establish a new clinical staging standard for nasopharyngeal carcinoma (NPC), based on intensity-modulated radiotherapy (IMRT), through a prospective multicenter clinical trial.Experiment Design492 NPC patients were selected from six hospitals in the Guangxi Zhuang Autonomous Region, China from January 2006 to December 2009. Kaplan-Meier method was adopted to calculate survival rates. Log-rank test was used to compare survival differences.ResultsAccording to the seventh edition of the UICC/AJCC staging system, the differences between T1, T2 and T3 are not statistically significant, suggesting that T1, T2 and T3 could be combined as new T1. There were significant differences between all N stages except those of N3a and N3b, suggesting that N3a and N3b could be combined as new N3. Additionally, the overall survival (OS) curves of stages I, II, III and IVa were not significantly different. Therefore, we propose a new clinical NPC staging standard based on magnetic resonance imaging (MRI) and IMRT as T stage (including T1 and T2), N stage (including N0, N1, N2 and N3) and clinical staging includes I (T1N0M0), II (T1N1-2M0, T2N0M0), III (T2N1-2M0), IVa (TxN3M0) and IVb (TxNxM1). Recommended staging system performs better in risk difference and distribution balance. Furthermore, the differences in the 5-year curves of local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and OS were all statistically more significant than the seventh edition of the UICC/AJCC staging system.ConclusionsProposed staging system is more adaptable to IMRT and predicts the prognosis of NPC patients more accurately.

BackgroundChemoresistance is one of the leading causes that severely limits the success of osteosarcoma treatment. Evaluating chemoresistance before chemotherapy poses a new challenge for researchers. We established an effective chemoresistance risk scoring model for prechemotherapy osteosarcoma using single-cell sequencing.MethodsWe comprehensively analyzed osteosarcoma data from the bulk mRNA sequencing dataset TARGET-OS and the single-cell RNA sequencing (scRNA-seq) dataset GSE162454. Chemoresistant tumor clusters were identified using enrichment analysis and AUCell scoring. Its differentiated trajectory was achieved with inferCNV and pseudotime analysis. Ligand–receptor interactions were annotated with iTALK. Furthermore, we established a chemoresistance risk scoring model using LASSO regression based on scRNA-seq-based markers of chemoresistant tumor clusters. The TARGET-OS dataset was used as the training group, and the bulk mRNA array dataset GSE33382 was used as the validation group. Finally, the performance was verified for its discriminatory ability and calibration.ResultsUsing bulk RNA data, we found that osteogenic expression was upregulated in chemoresistant osteosarcoma as compared to chemosensitive osteosarcoma. Then, we transferred the bulk RNA findings to scRNA-seq and noticed osteosarcoma tumor clusters C14 and C25 showing osteogenic cancer stem cell expression patterns, which fit chemoresistant characteristics. C14 and C25 possessed bridge roles in interactions with other clusters. On the one hand, they received various growth factor stimulators and could potentially transform into a proliferative state. On the other hand, they promote local tumor angiogenesis, bone remodeling and immunosuppression. Next, we identified a ten-gene signature from the C14 and C25 markers and constructed a chemoresistant risk scoring model using LASSO regression model. Finally, we found that chemoresistant osteosarcoma had higher chemoresistance risk score and that the model showed good discriminatory ability and calibration in both the training and validation groups (AUCtrain = 0.82; AUCvalid = 0.84). Compared with that of the classic bulk RNA-based model, it showed more robust performance in validation environment (AUCvalid-scRNA = 0.84; AUCvalid-bulk DEGs = 0.54).ConclusionsOur work provides insights into understanding chemoresistant osteosarcoma tumor cells and using single-cell sequencing to establish a chemoresistance risk scoring model. The model showed good discriminatory ability and calibration and provided us with a feasible way to evaluate chemoresistance in prechemotherapy osteosarcoma.

The present study aimed to investigate the cervical lymph node metastasis of nasopharyngeal carcinoma (NPC) and to establish a novel N staging standard for NPC, based on intensity modulated radiation therapy (IMRT) via a prospective multicenter clinical trial. Between January 2006 and December 2009, a total of 492 patients with NPC without distant metastasis were included in the present study. All patients were treated with IMRT. According to Radiation Therapy Oncology Group division standards, the present study proposed a novel N staging system following the review of magnetic resonance images in comparison with the 7th edition of Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system. Retropharyngeal lymph nodes, cervical lymph node level and cervical lymph node laterality were independent prognostic factors used in multivariate analyses. According to the results of the risk variety, the present study suggested that the novel N staging system included: N0 (no lymph node metastasis), N1 [retropharyngeal or/and unilateral upper cervical (I, II, III, Va, VIIb, VIII, IX and X regions) lymph node metastasis], N2 [bilateral upper cervical (I, II, III, Va, VIIb, VIII, IX and X regions) lymph node metastasis] and N3 (lymph node metastasis in IVa and Vb regions and their lower regions). The novel N staging system proposed in the present study performs better in risk difference and distribution balance. Furthermore, the differences of 5-year curves of distant metastasis-free survival and overall survival had greater statistically significant differences compared with the 7th edition of the UICC/AJCC staging system. The present study suggested a novel N staging system for cervical lymph node metastasis of NPC, which may predict the prognosis of patients with NPC in a more objective and accurate way.