Multifunctional Bagasse Foam with Improved Thermal Insulation and Flame Retardancy by a Borax-Induced Self-Assembly and Ambient Pressure Drying Technique.

Cellulose foams are considered an effective alternative to plastic foam, because of their advantages of low density, high porosity, low thermal conductivity, and renewable nature. However, they still suffer from complex processing, poor mechanical properties, and flammability. As an agricultural waste, bagasse is rich in cellulose, which has attracted much attention. Inspired by the fact that borate ions can effectively enhance the strength of plant tissue by their cross-linking with polysaccharides, the present work designs and fabricates a series of multifunctional bagasse foams with robust strength and improved thermal insulation and flame retardancy via a unique borax-induced self-assembly and atmospheric pressure drying route using bagasse as a raw material, borate as a cross-linking agent, and chitosan as an additive. As a result, the optimized foam exhibits a high porosity (93.5%), a high hydrophobic water contact angle (150.4°), a low thermal conductivity (63.4 mW/(m·K) at 25 °C), and an outstanding flame retardancy. The present study provides a novel and inspiring idea for large-scale production of cellulose foams through an environmentally friendly and cost-effective approach.

Structural basis for sugar perception by Drosophila gustatory receptors.

Insects rely on a family of seven transmembrane proteins called gustatory receptors (GRs) to encode different taste modalities, such as sweet and bitter. We report structures of Drosophila sweet taste receptors GR43a and GR64a in the apo and sugar-bound states. Both GRs form tetrameric sugar-gated cation channels composed of one central pore domain (PD) and four peripheral ligand-binding domains (LBDs). Whereas GR43a is specifically activated by the monosaccharide fructose that binds to a narrow pocket in LBDs, disaccharides sucrose and maltose selectively activate GR64a by binding to a larger and flatter pocket in LBDs. Sugar binding to LBDs induces local conformational changes, which are subsequently transferred to the PD to cause channel opening. Our studies reveal a structural basis for sugar recognition and activation of GRs.

Effects of plant-derived protein and rapeseed oil on growth performance and gut microbiomes in rainbow trout.

BACKGROUND: Rainbow trout (Oncorhynchus mykiss) is becoming popular with the increased demand for fish protein. However, the limited resources and expense of fish meal and oil have become restrictive factors for the development of the rainbow trout related industry. To solve this problem, plant-derived proteins and vegetable oils have been developed as alternative resources. The present study focuses on evaluating the effects of two experimental diets, FMR (fish meal replaced with plant-derived protein) and FOR (fish oil replaced with rapeseed oil), through the alteration of the gut microbiota in triploid rainbow trout. The commercial diet was used in the control group (FOM). RESULTS: Amplicon sequencing of the 16S and 18S rRNA genes was used to assess the changes in gut bacteria and fungi. Our analysis suggested that the α-diversity of both bacteria and fungi decreased significantly in the FMR and FOR groups, and ß-diversity was distinct between FOM/FMR and FOM/FOR based on principal coordinate analysis (PCoA). The abundance of the Planctomycetota phylum increased significantly in the FMR group, while that of Firmicutes and Bacteroidetes decreased. We also found that the fungal phylum Ascomycota was significantly increased in the FMR and FOR groups. At the genus level, we found that the abundance of Citrobacter was the lowest and that of pathogenic Schlesneria, Brevundimonas, and Mycoplasma was highest in the FMR and FOR groups. Meanwhile, the pathogenic fungal genera Verticillium and Aspergillus were highest in the FMR and FOR groups. Furthermore, canonical correspondence analysis (CCA) and network analysis suggested that the relatively low-abundance genera, including the beneficial bacteria Methylobacterium, Enterococcus, Clostridium, Exiguobacterium, Sphingomonas and Bacteroides and the fungi Papiliotrema, Preussia, and Stachybotrys, were positively correlated with plant protein or rapeseed oil. There were more modules that had the above beneficial genera as the hub nodes in the FMR and FOR groups. CONCLUSIONS: Our study suggested that the FMR and FOR diets could affect the gut microbiome in rainbow trout, which might offset the effects of the dominant and pathogenic microbial genera. This could be the underlying mechanism of explaining why no significant difference was observed in body weight between the different groups.

Debridement-Reconstruction-Docking Management System Versus Ilizarov Technique for Lower-Extremity Osteomyelitis.

BACKGROUND: Osteomyelitis causes marked disability and is one of the most challenging diseases for orthopaedists to treat because of the considerable rate of infection recurrence. In this study, we proposed and assessed the debridement-reconstruction-docking (DRD) system for the treatment of lower-extremity osteomyelitis. This procedure comprises 3 surgical stages and 2 preoperative assessments; namely, pre-debridement assessment, debridement, pre-reconstruction assessment, reconstruction, and docking-site management. We evaluated the use of the DRD system compared with the Ilizarov technique, which is defined as a 1-stage debridement, osteotomy, and bone transport. METHODS: This retrospective cohort included 289 patients who underwent either DRD or the Ilizarov technique for the treatment of lower-extremity osteomyelitis at a single institution between January 2013 and February 2021 and who met the eligibility criteria. The primary outcome was the rate of infection recurrence. Secondary outcomes included the external fixator index (EFI), refracture rate, and the Paley classification for osseous and functional results. An inverse-probability-weighted regression adjustment model was utilized to estimate the effect of the DRD system and Ilizarov technique on the treatment of lower-extremity osteomyelitis. RESULTS: A total of 131 and 158 patients underwent DRD or the Ilizarov technique, respectively. The inverse-probability-weighted regression adjustment model suggested that DRD was associated with a significant reduction in infection recurrence (risk ratio [RR], 0.26; 95% confidence interval [CI], 0.13 to 0.50; p < 0.001) and EFI (-6.9 days/cm, 95% CI; -8.3 to -5.5; p < 0.001). Patients in the DRD group had better Paley functional results than those in the Ilizarov group (ridit score, 0.55 versus 0.45; p < 0.001). There was no significant difference between the 2 groups in the rate of refracture (RR, 0.87; 95% CI, 0.42 to 1.79; p = 0.71) and Paley osseous results (ridit score, 0.51 versus 0.49; p = 0.39). CONCLUSIONS: In this balanced retrospective cohort of patients with lower-extremity osteomyelitis, the use of the DRD system was associated with a reduced rate of infection recurrence, a lower EFI, and better Paley functional results compared with the use of the Ilizarov technique. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Characterization of TIM-3 Expression and Its Correlation with TNF-α and IFN-γ in Patients with Surgically Resected Lung Adenocarcinoma.

Objective: T cell immunoglobulin and mucin-containing protein-3 (TIM-3) is an important immune checkpoint, but its role in lung cancer is still not clear. In this study, we investigated TIM-3 protein expression and its correlation with TNF-α and IFN-γ by examining the tissues of patients with lung adenocarcinoma. Methods: We detected the mRNA quantity of TIM-3, TNF-α, and IFN-γ in 40 surgically resected specimens from patients with lung adenocarcinoma by real-time quantitative polymerase chain reaction (qRT-PCR). The protein expression of TIM-3, TNF-α, and IFN-γ was assessed in normal tissues, paracarcinoma tissues, and tumor tissues by western blotting, respectively. The relevance between the expression and clinicopathological information of the patients was analyzed. Results: The results showed that the expression level of TIM-3 was higher in tumor tissues than normal tissues and paracancerous tissues (P < 0.05). On the contrary, the expression of TNF-α and IFN-γ in tumor tissues was lower than normal tissues and paracarcinoma tissues (P < 0.05). However, the expression levels of IFN-γ mRNA were not observed to be significantly different between cancerous tissues and adjacent tissues. While TIM-3 protein expression in cancer tissues of patients with lymph node metastasis was higher than in patients without metastasis, the expression of TNF-α and IFN-γ was lower (P < 0.05). Importantly, the expression of TIM-3 was negatively correlated with the expression of TNF-α and IFN-γ, and the expression of TNF-α was found to be positively correlated with IFN-γ in the patient. Conclusion: The high expression of TIM-3, the low expression of TNF-α and IFN-γ, and the synergistic effect of TNF-α and IFN-γ in patients with lung adenocarcinoma were closely related to poor clinicopathological characteristics. Overexpression of TIM-3 may play an important role in the relationship between TNF-α and IFN-γ secretion and poor clinicopathological characteristics.

Lysosomal Ion Channels and Lysosome-Organelle Interactions.

Intracellular organelles exchange their luminal contents with each other via both vesicular and non-vesicular mechanisms. By forming membrane contact sites (MCSs) with ER and mitochondria, lysosomes mediate bidirectional transport of metabolites and ions between lysosomes and organelles that regulate lysosomal physiology, movement, membrane remodeling, and membrane repair. In this chapter, we will first summarize the current knowledge of lysosomal ion channels and then discuss the molecular and physiological mechanisms that regulate lysosome-organelle MCS formation and dynamics. We will also discuss the roles of lysosome-ER and lysosome-mitochondria MCSs in signal transduction, lipid transport, Ca 2+ transfer, membrane trafficking, and membrane repair, as well as their roles in lysosome-related pathologies.

Correction: Zheng et al. Glycolysis-Related SLC2A1 Is a Potential Pan-Cancer Biomarker for Prognosis and Immunotherapy. Cancers 2022, 14, 5344.

The authors wish to make the following corrections to this paper [...].

A prion-like domain of TFEB mediates the co-aggregation of TFEB and mHTT.

The aggregation of mutant HTT (huntingtin; mHTT) is a hallmark of Huntington disease (HD). mHTT aggregates interact and sequester dozens of proteins and affect diverse key cellular functions. Here we report that TFEB (transcription factor EB), a master regulator of lysosome biogenesis and autophagy, is yet another protein that co-aggregates with mHTT. We also found the mHTT-TFEB co-aggregation is mediated by a prion-like domain (PrLD) near the N terminus of TFEB. Our findings point out a possible limitation for therapeutic strategies targeting TFEB to clear mHTT, and also provided a possible explanation for controversies that TFEB overexpression lowered soluble mHTT in some HD models but failed to reduce mHTT aggregates or HD pathology in others. Moreover, we found that TFE3, another MiT family transcription factor that shares overlapping functions with TFEB, lacks PrLD and does not co-aggregate with mHTT, and thus might serve as an alternative drug target for HD.

Addition of bevacizumab to EGFR tyrosine kinase inhibitors in advanced NSCLC: an updated systematic review and meta-analysis.

Background: The synergistic effects of antiangiogenic inhibitor bevacizumab and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) therapy were encouraging in patients with EGFR-mutant advanced NSCLC, though some controversy remains. The specific subgroup of patients who might benefit most from the EGFR-TKI and bevacizumab combination therapy is yet to be determined. Methods: Randomized clinical trials (RCTs) that had compared the clinical efficacy of EGFR-TKI and bevacizumab combination therapy with EGFR-TKI monotherapy in treating EGFR-mutant advanced NSCLC patients published before 23 December 2022 were searched in the Cochrane, PubMed and Embase. We performed a meta-analysis for the overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and treatment-related adverse events with a grade equal or more than 3 (grade≥3 TRAEs). Subgroup analyses of PFS and OS stratified by clinical characteristics and treatment were conducted. Results: We included 10 RCTs involving 1520 patients. Compared with EGFR-TKI monotherapy, addition of bevacizumab to EGFR-TKI resulted in a significantly higher PFS (hazard ratio (HR) = 0.74, 95% confidence interval (95% CI): 0.62-0.87)) and ORR (risk ratio (RR) = 1.07, 95% CI: 1.01-1.13). However, no significant difference in OS (HR = 0.96, 95% CI: 0.83-1.12) was noticed. Patients with EGFR-mutant advanced NSCLC receiving combination therapy showed PFS improvement regardless of gender (male or female), Eastern Cooperative Oncology Group performance status (0 or 1), baseline central nervous system (CNS) metastasis (presence or absence) and EGFR mutation type (19del or 21L858R). Subgroup analyses showed that, with the treatment of bevacizumab and EGFR-TKI, patients who ever smoked achieved significantly better OS and PFS benefits (HR = 0.68, 95% CI: 0.48-0.95; HR = 0.59, 95% CI: 0.46-0.74, respectively), and those aged <75 years and the Asian population had significantly prolonged PFS (HR = 0.69, 95% CI: 0.52-0.91; HR = 0.71, 95% CI: 0.58-0.87; respectively). The superiority of EGFR-TKI and bevacizumab combination therapy against EGFR-TKI monotherapy in improving PFS was more significant in the erlotinib regimen subgroup. The risk of grade≥3 TRAEs was remarkably higher in the combination therapy group (HR = 1.73, 95% CI: 1.39-2.16). Conclusion: Addition of bevacizumab to EGFR-TKI therapy provided significantly better PFS and ORR for EGFR-mutant advanced NSCLC patients, though with higher risk of grade≥3 TRAEs. Patients who ever smoked, aged <75 years, and Asian population might benefit more from the combination regimen. Systematic Review Registration: This systematic review and meta-analysis was registered in the PROSPERO database (CRD42023401926).

Glycolysis-Related SLC2A1 Is a Potential Pan-Cancer Biomarker for Prognosis and Immunotherapy.

SLC2A1 plays a pivotal role in cancer glycometabolism. SLC2A1 has been proposed as a putative driver gene in various cancers. However, a pan-cancer analysis of SLC2A1 has not yet been performed. In this study, we explored the expression and prognosis of SLC2A1 in pan-cancer across multiple databases. We conducted genetic alteration, epigenetic, and functional enrichment analyses of SLC2A. We calculated the correlation between SLC2A1 and tumor microenvironment using the TCGA pan-cancer dataset. We observed high expression levels of SLC2A1 with poor prognosis in most cancers. The overall genetic alteration frequency of SLC2A1 was 1.8% in pan-cancer, and the SLC2A1 promoter was hypomethylation in several cancers. Most m6A-methylation-related genes positively correlated with the expression of SLC2A1 in 33 TCGA cancers. Moreover, SLC2A1 was mainly related to the functions including epithelial-mesenchymal transition, glycolysis, hypoxia, cell-cycle regulation, and DNA repair. Finally, SLC2A1 positively associated with neutrophils and cancer-associated fibroblasts in the tumor microenvironment of most cancers and significantly correlated with TMB and MSI in various cancers. Notably, SLC2A1 was remarkably positively correlated with PD-L1 and CTLA4 in most cancers. SLC2A1 might serve as an attractive pan-cancer biomarker for providing new insights into cancer therapeutics.

The Role of Staphylococcal Biofilm on the Surface of Implants in Orthopedic Infection.

Despite advanced implant sterilization and aseptic surgical techniques, implant-associated infection remains a major challenge for orthopedic surgeries. The subject of bacterial biofilms is receiving increasing attention, probably as a result of the wide acknowledgement of the ubiquity of biofilms in the clinical environment, as well as the extreme difficulty in eradicating them. Biofilm can be defined as a structured microbial community of cells that are attached to a substratum and embedded in a matrix of extracellular polymeric substances (EPS) that they have produced. Biofilm development has been proposed as occurring in a multi-step process: (i) attachment and adherence, (ii) accumulation/maturation due to cellular aggregation and EPS production, and (iii) biofilm detachment (also called dispersal) of bacterial cells. In all these stages, characteristic proteinaceous and non-proteinaceous compounds are expressed, and their expression is strictly controlled. Bacterial biofilm formation around implants shelters the bacteria and encourages the persistence of infection, which could lead to implant failure and osteomyelitis. These complications need to be treated by major revision surgeries and extended antibiotic therapies, which could lead to high treatment costs and even increase mortality. Effective preventive and therapeutic measures to reduce risks for implant-associated infections are thus in urgent need.

High-purity magnesium screws modulate macrophage polarization during the tendon-bone healing process in the anterior cruciate ligament reconstruction rabbit model.

Magnesium (Mg) screws perform clinical potential in anterior cruciate ligament (ACL) reconstruction, and promote fibrocartilaginous entheses regeneration at the femoral entrance. We aim to prove that high-purity Magnesium (HP Mg) screws modulate macrophage polarization in fibrocartilage interface regeneration both in vitro and in vivo. HP Mg extracts performed good cytocompatibility and significantly promoted M2 macrophage polarization in the flow cytometry and ELISA assays. M2 macrophages stimulated fibrochondrocyte differentiation of co-cultured hBMSCs, and HP Mg extracts had synergistic effect on the process. Then we applied HP Mg screws, with Ti screws as control, in the ACL reconstruction rabbit model. In the histological and immunofluorescence analysis, HP Mg screws inhibited M1 polarization at 2 weeks and highly promoted M2 polarization at 2 and 4 weeks at the tendon-bone interface. Furthermore, regeneration of fibrocartilaginous entheses, rather than the fibrovascular scar interface, was detected in the HP Mg group at 12 weeks. For further mechanism study via RNA-seq detection and WB assays, we found that AKT1 was highly activated in M2 polarization, and HP Mg could stimulate AKT1 expression, rather than AKT2, in the early phase of tendon-bone healing. Our study elucidated macrophage polarization during tendon-bone healing process and emphasized HP Mg on M2 polarization and fibrocartilage interface regeneration via the selective activation of AKT1 and PI3K/AKT pathway.

Lysosomal solute and water transport.

Lysosomes mediate hydrolase-catalyzed macromolecule degradation to produce building block catabolites for reuse. Lysosome function requires an osmo-sensing machinery that regulates osmolytes (ions and organic solutes) and water flux. During hypoosmotic stress or when undigested materials accumulate, lysosomes become swollen and hypo-functional. As a membranous organelle filled with cargo macromolecules, catabolites, ions, and hydrolases, the lysosome must have mechanisms that regulate its shape and size while coordinating content exchange. In this review, we discussed the mechanisms that regulate lysosomal fusion and fission as well as swelling and condensation, with a focus on solute and water transport mechanisms across lysosomal membranes. Lysosomal H+, Na+, K+, Ca2+, and Cl- channels and transporters sense trafficking and osmotic cues to regulate both solute flux and membrane trafficking. We also provide perspectives on how lysosomes may adjust the volume of themselves, the cytosol, and the cytoplasm through the control of lysosomal solute and water transport.

Chiral Supramolecular Hydrogel Loaded with Dimethyloxalyglycine to Accelerate Chronic Diabetic Wound Healing by Promoting Cell Proliferation and Angiogenesis.

Chronic refractory wounds are one of the most serious complications of diabetes, and the effects of common treatments are limited. Chiral hydrogel combined with dimethyloxalyglycine (DMOG) as a dressing is a promising strategy for the treatment of chronic wounds. In this research, we have developed a DMOG-loaded supramolecular chiral amino-acid-derivative hydrogel for wound dressings for full-thickness skin regeneration of chronic wounds. The properties of the materials, the ability of sustained release drugs, and the ability to promote angiogenesis were tested in vitro, and the regeneration rate and repair ability of full-thickness skin were tested in vivo. The chiral hydrogel had the ability to release drugs slowly. It can effectively promote cell migration and angiogenesis in vitro, and promote full-thickness skin regeneration and angiogenesis in vivo. This work offers a new approach for repairing chronic wounds completely through a supramolecular chiral hydrogel loaded with DMOG.

The Three Two-Pore Channel Subtypes from Rabbit Exhibit Distinct Sensitivity to Phosphoinositides, Voltage, and Extracytosolic pH.

Two pore channels (TPCs) are implicated in vesicle trafficking, virus infection, and autophagy regulation. As Na+- or Ca2+-permeable channels, TPCs have been reported to be activated by NAADP, PI(3,5)P2, and/or high voltage. However, a comparative study on the function and regulation of the three mammalian TPC subtypes is currently lacking. Here, we used the electrophysiological recording of enlarged endolysosome vacuoles, inside-out and outside-out membrane patches to examine the three TPCs of rabbit (Oryctolagus cuniculus, or Oc) heterologously expressed in HEK293 cells. While PI(3,5)P2 evoked Na+ currents with a potency order of OcTPC1 > OcTPC3 > OcTPC2, only OcTPC2 displayed a strict dependence on PI(3,5)P2. Both OcTPC1 and OcTPC3 were activatable by PI3P and OcTPC3 was also activated by additional phosphoinositide species. While OcTPC2 was voltage-independent, OcTPC1 and OcTPC3 showed voltage dependence with OcTPC3 depending on high positive voltages. Finally, while OcTPC2 preferred a luminal pH of 4.6−6.0 in endolysosomes, OcTPC1 was strongly inhibited by extracytosolic pH 5.0 in both voltage-dependent and -independent manners, and OcTPC3 was inhibited by pH 6.0 but potentiated by pH 8.0. Thus, the three OcTPCs form phosphoinositide-activated Na+ channels with different ligand selectivity, voltage dependence, and extracytosolic pH sensitivity, which likely are optimally tuned for function in specific endolysosomal populations.

Mining the Prognostic Role of DNA Methylation Heterogeneity in Lung Adenocarcinoma.

Purpose: DNA methylation heterogeneity is a type of tumor heterogeneity in the tumor microenvironment, but studies on the identification of the molecular heterogeneity of the lung adenocarcinoma genome with respect to DNA methylation sites and their roles in lung cancer progression and prognosis are scarce. Methods: Prognosis-associated DNA methylation subtypes were filtered by the Cox proportional hazards model and then established by unsupervised cluster analysis. Association analysis of these subtypes with clinical features and functional analysis of annotated genes potentially affected by methylation sites were performed. The robustness of the model was further tested by a Bayesian network classifier. Results: Over 7 thousand methylation sites were associated with lung adenocarcinoma prognosis. We identified seven molecular methylation subtypes, including 630 methylation sites. The subtypes yielded the most stable results for differentiating methylation profiles, prognosis, and gene expression patterns. The annotated genes potentially affected by these methylation sites are enriched in biological processes such as morphogenesis and cell adhesion, but their individual impact on the tumor microenvironment and prognosis is multifaceted. Discussion. We revealed that DNA methylation heterogeneity could be clustered and associated with the clinical features and prognosis of lung adenocarcinoma, which could lead to the development of a novel molecular tool for clinical evaluation.

Establishing a TNM-like risk classification for metachronous second pulmonary adenocarcinoma in patients with previously resected pulmonary adenocarcinoma.

Background: For metachronous second pulmonary adenocarcinoma (msPAD) in patients with resected PAD, the method to distinguish tumour clonality has not yet been well established, which makes it difficult to determine accurate staging and predict prognosis. Methods: Patients received surgery for the primary and encountered msPAD were recruited into the Surveillance, Epidemiology, and End Results database. We extracted overall survival 1 (OS1) for the primary, overall survival 2 (OS2) for the msPAD, and defined interval survival as the interval time between the first and second PAD. Based on the nomogram and recursive partitioning analysis, a tumor, node, metastasis staging system (TNM)-like risk stratification system was established for OS2 on the premise of suspending the dispute of tumor clonality. Results: A total of 1,045 patients were identified. There is no significant association between interval survival and OS2. A TNM-like risk stratification system was established based on the independent pathological factors for prognosis, including tumor diameter (2nd), node metastasis (2nd), grade (2nd), and extrapulmonary metastasis (2nd). The proposed risk stratification system present well capacity in predicting and stratifying prognosis. Compared with the TNM stage system, the proposed risk stratification system presents a smaller Akaike information criterion (AIC) but larger c-index, and generates higher accuracy to predict prognosis at 160 months of follow-up according to the time-dependent receiver operating curve (ROC) curve. Conclusions: In conclusion, the TNM-like risk stratification appears to be suitable for prognostic prediction and risk stratification for msPAD patients with former PAD resection. This model validates and refines the known classification rules based on the easily collected variables, and highlights potentially clinical implications.

Preparation of the porous carbon-based solid acid from starch for efficient degradation of chitosan to D-glucosamine.

Effective degradation of chitosan to D-glucosamine is considered to make a great contribution for the development of the medical industry. To address this issue, a porous carbon-based solid acid catalyst (PCSA) functionalized with -OH, -COOH and -SO3H groups was successfully prepared. Typically, the physicochemical properties of PCSA were deeply determined by a series of characterization technique including FT-IR, TGA, RM, NH3-TPD, SEM and Element Analysis. Moreover, the catalytic performances of PCSA towards to D-glucosamine production from chitosan were evaluated. In particular, the effects of catalyst acid density, ratio of acidic groups, chitosan concentration, reaction temperature, reaction time and catalyst dosage on the yield of D-glucosamine were investigated in detail. Interestingly, the experimental results indicated that a yield of D-glucosamine as high as 90.5% was achieved, and no obvious deactivation occurred even after six consecutive cycles. In light of the advantages of superior activity/recyclability and low cost, the starch-derived solid acid developed in this work might possess the broad industrial application prospects.

Establishing a prognostic model for metachronous second squamous cell lung cancer in patients with resected squamous cell lung cancer.

BACKGROUND: For metachronous second pulmonary squamous cell carcinoma (msPSC) in patients with resected PSC, the method to distinguish tumour clonality has not yet been well established, which makes it difficult to determine accurate staging and predict prognosis. METHODS: Patients who underwent surgery for first PSC and encountered msPSC were recruited from the Surveillance, Epidemiology, and End Results (SEER) database. We extracted overall survival 1 (OS1) for the first PSC, overall survival 2 (OS2) for msPSC, and interval survival for the time interval between the first and second PSC. The nomogram was calibrated for OS2, and recursive partitioning analysis (RPA) was performed for risk stratification. RESULTS: A total of 617 patients were identified. Several independent prognostic factors were identified and integrated into the nomogram for OS2, including gender, age (2nd), nodal status (1st), node metastasis (2nd), and extrapulmonary metastasis (2nd). The calibration curves showed optimal agreement between the predictions and actual observations, and the c-index was 0.678. Surgery was associated with longer survival for msPSC patients. The prognosis of sublobectomy was comparable and inferior to that of lobectomy in the low- and moderate-risk groups, respectively. Radiotherapy was associated with better outcomes in patients who did not undergo surgery. CONCLUSIONS: The RPA-based clinical nomogram appears to be suitable for the prognostic prediction and risk stratification of OS2 in msPSC. This practical system may help clinicians make decisions and design clinical studies.