Mesenchymal Stem Cell-Loaded Hydrogel Improves Surgical Treatment for Chronic Cerebral Ischemia.

Chronic cerebral ischemia (CCI) results in a prolonged insufficient blood supply to the brain tissue, leading to impaired neuronal function and subsequent impairment of cognitive and motor abilities. Our previous research showed that in mice with bilateral carotid artery stenosis, the collateral neovascularization post Encephalo-myo-synangiosis (EMS) treatment could be facilitated by bone marrow mesenchymal stem cells (MSCs) transplantation. Considering the advantages of biomaterials, we synthesized and modified a gelatin hydrogel for MSCs encapsulation. We then applied this hydrogel on the brain surface during EMS operation in rats with CCI, and evaluated its impact on cognitive performance and collateral circulation. Consequently, MSCs encapsulated in hydrogel significantly augment the therapeutic effects of EMS, potentially by promoting neovascularization, facilitating neuronal differentiation, and suppressing neuroinflammation. Furthermore, taking advantage of multi-RNA-sequencing and in silico analysis, we revealed that MSCs loaded in hydrogel regulate PDCD4 and CASP2 through the overexpression of miR-183-5p and miR-96-5p, thereby downregulating the expression of apoptosis-related proteins and inhibiting early apoptosis. In conclusion, a gelatin hydrogel to enhance the functionality of MSCs has been developed, and its combination with EMS treatment can improve the therapeutic effect in rats with CCI, suggesting its potential clinical benefit.

Biomaterials targeting the microenvironment for spinal cord injury repair: progression and perspectives.

Spinal cord injury (SCI) disrupts nerve pathways and affects sensory, motor, and autonomic function. There is currently no effective treatment for SCI. SCI occurs within three temporal periods: acute, subacute, and chronic. In each period there are different alterations in the cells, inflammatory factors, and signaling pathways within the spinal cord. Many biomaterials have been investigated in the treatment of SCI, including hydrogels and fiber scaffolds, and some progress has been made in the treatment of SCI using multiple materials. However, there are limitations when using individual biomaterials in SCI treatment, and these limitations can be significantly improved by combining treatments with stem cells. In order to better understand SCI and to investigate new strategies for its treatment, several combination therapies that include materials combined with cells, drugs, cytokines, etc. are summarized in the current review.

Exotic plantations differ in "nursing" an understory invader: A probe into invasional meltdown.

Forest plantations most likely promote exotic plant invasion. Using an in situ monitoring method, this study investigated the traits correlated with growth and reproduction of an understory invader, Phytolacca americana L., and ecological factors including understory irradiance, soil stoichiometry and microbial patterns associated with these traits in different exotic plantations of Robinia pseudoacacia L. and Pinus thunbergii Parl. at Mount Lao, Qingdao, China. We found that the traits of P. americana underneath the R. pseudoacacia stand might be situated at the fast side of the trait economic spectrum. The R. pseudoacacia stand appeared to "nurse" P. americana. Furthermore, we intended to explain the nurse effects of R. pseudoacacia stands by examining their ecological factors. First, the R. pseudoacacia stand created understory light attenuation, which matched the sciophilous feature of P. americana. Second, the soil beneath the R. pseudoacacia stand might benefit P. americana more since the soil has greater resource availability. Third, a higher microbial diversity was found in the soil derived from P. americana underneath the R. pseudoacacia stand. A greater abundance of plant pathogens was detected in the soil derived from P. americana in the R. pseudoacacia stand, while more abundant mycorrhizal fungi were detected in the P. thunbergii stand. We speculate that plant pathogens can defend P. americana from aggression from other understory competitors. The mycorrhizal fungi in the P. thunbergii stand might benefit P. americana while simultaneously benefiting other understory plants. Intensive competition from other plants might interfere with P. americana. The potential relationships between plant performance and ecological factors may explain the invasion mechanism of P. americana. The present study provides a novel insight on the facilitative effects of exotic tree plantation on an exotic herb through the modification of soil biota, with implications for the biocontrol of invasive species and forest management and conservation.

Recent advances in electrosynthesis of H2O2via two-electron oxygen reduction reaction.

The electrosynthesis of hydrogen peroxide (H2O2) via a selective two-electron oxygen reduction reaction (2e- ORR) presents a green and low-energy-consumption alternative to the traditional, energy-intensive anthraquinone process. This review encapsulates the principles of designing relational electrocatalysts for 2e- ORR and explores remaining setups for large-scale H2O2 production. Initially, the review delineates the fundamental reaction mechanisms of H2O2 production via 2e- ORR and assesses performance. Subsequently, it methodically explores the pivotal influence of microstructures, heteroatom doping, and metal hybridization along with setup configurations in achieving a high-performance catalyst and efficient reactor for H2O2 production. Thereafter, the review introduces a forward-looking methodology that leverages the synergistic integration of catalysts and reactors, aiming to harmonize the complementary characteristics of both components. Finally, it outlines the extant challenges and the promising avenues for the efficient electrochemical production of H2O2, setting the stage for future research endeavors.

Comparison of Drug-Coated Balloon and Drug-Eluting Stent for the Treatment of Small Vessel Disease (from the Dissolve SVD Randomized Trial).

The Dissolve drug-coated balloons (DCBs) is a new-generation DCB coated with paclitaxel of balloon surface, with midchain triglyceride excipient. Although the use of DCBs is a promising technique, little is known about the the clinical efficacy of the novel Dissolve DCB in coronary small vessel disease. This study was a prospective, randomized, multicenter, noninferiority trial comparing the Dissolve DCB with the Resolute drug-eluting stent (DES) in patients with a reference vessel diameter ≥2.25 and ≤2.75 mm. Patients with a reference vessel diameter ≥2.00 and <2.25 mm were enrolled in the very small vessel registry. The angiographic and clinical follow-up were planned at 9 months and 1 year in all patients, respectively. The primary end point was 9-month in-segment percentage diameter stenosis. A total of 247 patients with small vessel disease from 10 Chinese sites were included (Dissolve DCB, n = 118; Resolute DES, n = 129); 30 patients were treated with the DCB in the very small vessel cohort. The 9-month in-segment percentage diameter stenosis was 31.2 ± 2.0% with Dissolve DCB versus 26.1 ± 2.1% with Resolute DES; the 1-sided 97.5% upper confidence limit of the difference was 10.3% (p for noninferiority = 0.0002). At 12 months, the DCB and DES groups were associated with similar rates of target lesion failure (8.5% vs 6.1%, p = 0.28) and major adverse cardiac and cerebrovascular events (20.9% vs 13.6%, p = 0.12). In conclusion, the Dissolve DCB was noninferior to the Resolute DES for the primary end point of 9-month in-segment percentage diameter stenosis in this multicenter, head-to-head, randomized trial (a safety and efficacy study of Dissolve In Treatment Of Coronary Small Vessel Disease; NCT03376646).

Enlarged Perivascular Space and Index for Diffusivity Along the Perivascular Space as Emerging Neuroimaging Biomarkers of Neurological Diseases.

The existence of lymphatic vessels or similar clearance systems in the central nervous system (CNS) that transport nutrients and remove cellular waste is a neuroscientific question of great significance. As the brain is the most metabolically active organ in the body, there is likely to be a potential correlation between its clearance system and the pathological state of the CNS. Until recently the successive discoveries of the glymphatic system and the meningeal lymphatics solved this puzzle. This article reviews the basic anatomy and physiology of the glymphatic system. Imaging techniques to visualize the function of the glymphatic system mainly including post-contrast imaging techniques, indirect lymphatic assessment by detecting increased perivascular space, and diffusion tensor image analysis along the perivascular space (DTI-ALPS) are discussed. The pathological link between glymphatic system dysfunction and neurological disorders is the key point, focusing on the enlarged perivascular space (EPVS) and the index of diffusivity along the perivascular space (ALPS index), which may represent the activity of the glymphatic system as possible clinical neuroimaging biomarkers of neurological disorders. The pathological link between glymphatic system dysfunction and neurological disorders is the key point, focusing on the enlarged perivascular space (EPVS) and the index for of diffusivity along the perivascular space (ALPS index), which may represent the activity of the glymphatic system as possible clinical neuroimaging biomarkers of neurological disorders.

Mucin 1 promotes salivary gland cancer cell proliferation and metastasis by regulating the epidermal growth factor receptor signaling pathway.

Background/purpose: Salivary gland cancer (SGC) is the common malignant tumor of the head and neck region with poor prognosis. Mucin 1 (MUC1) has been reported to be associated with the development of cancer. However, whether MUC1 contributed to the progression of SGC remains to be explored. Materials and methods: Immunohistochemical analysis was used to explore the expression levels of MUC1 in SGC tissues. Cell proliferation, colony formation, wound healing, transwell, and xenograft assays were performed to examine the effects of MUC1 on SGC in vitro and in vivo. Results: We found that the expression level of MUC1 was significantly upregulated in SGC tissues, and the expression level of MUC1 was significantly correlated with lymph node metastasis and TNM stage of SGC. Further exploration demonstrated that MUC1 knockdown drastically inhibited, while its overexpression promoted, cell growth, colony formation, migration, and invasion abilities of SGC cells in vitro. MUC1 knockdown significantly inhibited tumor growth in vivo, and vice versa. More importantly, we found that MUC1 promotes malignant phenotypes of SGC cells by regulating the epidermal growth factor receptor (EGFR) signaling pathway. Conclusion: Our results revealed that MUC1 promotes the development of SGC by mediating the EGFR signaling pathway, which highlights the potential therapeutic target of MUC1/ EGFR in SGC.

Drug-eluting stent and drug-coated balloon for the treatment of de novo diffuse coronary artery disease lesions: A retrospective case series study.

BACKGROUND: The hybrid strategy of a combination of drug-eluting stent (DES) and drug-coated balloon (DCB) is promising for the treatment of de novo diffuse coronary artery disease (CAD). HYPOTHESIS: To investigate the efficacy and functional results of hybrid strategy. METHODS: This case series study included patients treated with a hybrid approach for de novo diffuse CAD between February 2017 and November 2021. Postprocedural quantitative flow ratio (QFR) was used to evaluate the functional results. The primary endpoint was procedural success rate. The secondary endpoints were major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction (MI) (including peri-procedural MI), and target vessel revascularization. RESULTS: A total of 109 patients with 114 lesions were treated. DES and DCB were commonly used in larger proximal segments and smaller distal segments, respectively. The mean QFR value was 0.9 ± 0.1 and 105 patients (96.3%) had values >0.8 in all the treated vessels. Procedural success was achieved in 106 (97.2%) patients. No cases of cardiac death were reported at a median follow-up of 19 months. Spontaneous MI occurred in three (2.8%) patients and target vessel revascularization in six (5.5%) patients. Estimated 2-year rate of MACE excluding peri-procedural MI was higher in the group with lower QFR value (12.1 ± 5.7% vs. 5.6 ± 4.4%, log-rank p = .035) (cut-off value 0.9). CONCLUSION: Hybrid strategy is a promising approach for the treatment of de novo diffuse CAD. Postprocedural QFR has some implications for prognosis and may be helpful in guiding this approach.

Pertinence of glioma and single nucleotide polymorphism of TERT, CCDC26, CDKN2A/B and RTEL1 genes in glioma: a meta-analysis.

Background: Previous genetic-epidemiological studies considered TERT (rs2736100), CCDC26 (rs4295627), CDKN2A/B (rs4977756) and RTEL1 (rs6010620) gene polymorphisms as the risk factors specific to glioma. However, the data samples of previous genetic-epidemiological studies are modest to determine whether they have definite association with glioma. Method: The study paid attention to systematically searching databases of PubMed, Embase, Web of Science (WoS), Scopus, Cochrane Library and Google Scholars. Meta-analysis under 5 genetic models, namely recessive model (RM), over-dominant model (O-DM), allele model (AM), co-dominant model (C-DM) and dominant model (DM) was conducted for generating odds ratios (ORs) and 95% confidence intervals (CIs). That was accompanied by subgroup analyses according to various racial groups. The software STATA 17.0 MP was implemented in the study. Result: 21 articles were collected. According to data analysis results, in four genetic models (AM, RM, DM and C-DM) TERT gene rs2736100 polymorphism, CCDC26 gene rs4295627 polymorphism, CDKN2A/B gene rs4977756 polymorphism and RTEL1 gene rs6010620 polymorphisms increased the risk of glioma in Caucasians to different degrees. In Asian populations, the CCDC26 gene rs4295627 polymorphism and CDKN2A/B gene rs4977756 polymorphism did not exhibit a relevance to the risk of glioma. It is suggested to cautiously explain these results as the sample size is small. Conclusion: The current meta-analysis suggested that the SNP of TERT (rs2736100), CCDC26 (rs4295627), CDKN2A/B (rs4977756) and RTEL1 (rs6010620) genes in glioma might increase risk of glioma, but there are ethnic differences. Further studies evaluating these polymorphisms and glioma risk are warranted.

Clinicopathological characteristics of pleomorphic adenoma from the labial gland: A 20-year experience with 173 cases in one single institution.

OBJECTIVE: Pleomorphic adenoma (PA) of the lip is not a common phenomenon, and existing literature provides limited information on the clinicopathological features of labial PA. STUDY DESIGN: Patients diagnosed with labial PA at our single institution over the past 20 years (2001-2020) was retrospectively screened and analyzed to investigate the epidemiologic and clinicopathological features of these tumors. RESULTS: A total of 173 cases were screened out, and the average age was 44.3 (range 7-82) years, with a peak incidence rate during the third decade. A slight predilection for men (52%) was observed, and PA occurs more frequently in the upper lip than in the lower lip, with a ratio of 14.7:1. On clinical examination, labial PAs usually present as painless masses that develop slowly with no systemic symptoms. Histologically, labial PAs contain myoepithelial and polygonal epithelial cells in myxoid, hyaline, fibrous, chondroid, and even osseous tissues, similar to those in other sites. Specifically, 15 of 173 patients with labial PA presented with cutaneous PA. CONCLUSION: Labial PA presents over a wide age range and dominantly occurs at the upper lip. Surgical resection is the major treatment strategy, and postoperative recurrence or malignant transformation of labial PA was extremely rare.

Hierarchically Porous Carbons with Highly Curved Surfaces for Hosting Single Metal FeN4 Sites as Outstanding Oxygen Reduction Catalysts.

Iron-nitrogen-carbon (FeNC) materials have emerged as a promising alternative to platinum-group metals for catalyzing the oxygen reduction reaction (ORR) in proton-exchange-membrane fuel cells. However, their low intrinsic activity and stability are major impediments. Herein, an FeN-C electrocatalyst with dense FeN4 sites on hierarchically porous carbons with highly curved surfaces (denoted as FeN4 -hcC) is reported. The FeN4 -hcC catalyst displays exceptional ORR activity in acidic media, with a high half-wave potential of 0.85 V (versus reversible hydrogen electrode) in 0.5 m H2 SO4 . When integrated into a membrane electrode assembly, the corresponding cathode displays a high maximum peak power density of 0.592 W cm-2 and demonstrates operating durability over 30 000 cycles under harsh H2 /air conditions, outperforming previously reported Fe-NC electrocatalysts. These experimental and theoretical studies suggest that the curved carbon support fine-tunes the local coordination environment, lowers the energies of the Fe d-band centers, and inhibits the adsorption of oxygenated species, which can enhance the ORR activity and stability. This work provides new insight into the carbon nanostructure-activity correlation for ORR catalysis. It also offers a new approach to designing advanced single-metal-site catalysts for energy-conversion applications.

A Randomized Comparison of 2 Different Drug-Coated Balloons for In-Stent Restenosis.

BACKGROUND: Although use of drug-coated balloons (DCB) is a promising technique, little is known about the clinical efficacy of the Dissolve DCB in drug-eluting stent (DES) in-stent restenosis (ISR). OBJECTIVES: This study sought to evaluate the efficacy and safety of the Dissolve DCB in patients with DES ISR. METHODS: This was a prospective, multicenter, randomized, noninferiority trial comparing Dissolve DCB with SeQuent Please DCB in patients with DES ISR. Angiographic and clinical follow-up was planned at 9 months in all patients. The primary endpoint was 9-month in-segment late loss. RESULTS: A total of 260 patients with ISR from 10 Chinese sites were included (Dissolve DCB, n = 128; SeQuent Please DCB, n = 132). Nine-month in-segment late loss was 0.50 ± 0.06 mm with Dissolve DCB vs 0.47 ± 0.07 mm with SeQuent Please DCB; the 1-sided 97.5% upper confidence limit of the difference was 0.18 mm (P for noninferiority = 0.03). Rates of target lesion failure and binary restenosis were numerical higher in the Dissolve DCB cohort compared with the SeQuent Please DCB cohort at 9 months (17.5% vs 10.7%; P = 0.12; 23.4% vs 16.4%; P = 0.19, respectively). At 9 months, major adverse cardiac and cerebrovascular events occurred in 36 patients (28.3%) vs 30 patients (22.9%) in the Dissolve DCB and SeQuent Please DCB groups, respectively. CONCLUSIONS: In this head-to-head randomized trial, the Dissolve DCB was noninferior to the SeQuent Please DCB for 9-month in-segment late loss. However, Dissolve DCB with its numerical increase in target lesion failure and binary restenosis warrants assessment in larger clinical trials (A Safety and Efficacy Study of Dissolve™ in Treatment of Coronary In-Stent Restenosis; NCT03373695).

Malignant sublingual gland tumors: A single-center retrospective analysis of 79 patients.

OBJECTIVES: To analyze and summarize the clinicopathological features, risk factors for cervical nodal metastasis, and prognostic factors of malignant sublingual gland tumors (MSLGT). METHODS: Patients diagnosed with MSLGT were retrospectively reviewed from January 2005 to December 2017 at Shanghai Ninth Hospital. The clinicopathological features were summarized, and the correlations between clinicopathological parameters, cervical nodal metastasis, and local-regional recurrence were evaluated using the Chi-square test. Kaplan-Meier method and Cox regression analysis were performed to assess the survival and independent prognostic factors. RESULTS: Seventy-nine patients were included, and the 5-year overall survival and disease-free survival rates was 85.7% and 71.7%, respectively. Gender and clinical tumor stage were risk factors for cervical nodal metastasis. Tumor size and pathological lymph node (LN) stage were independent prognostic factors for adenoid cystic carcinoma (ACC) of the sublingual gland; while age, pathological LN stage, and distant metastasis were prognostic factors for patients with non-ACC of the sublingual gland. Patients with higher clinical stage were more likely to undergo tumor recurrence. CONCLUSIONS: Malignant sublingual gland tumors are rare, and neck dissection should be performed in male MSLGT patients with higher clinical stage. Among patients with both ACC and non-ACC MSLGT patients, pN+ indicate a poor prognosis.

Association of Types of Sleep Apnea and Nocturnal Hypoxemia with Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy.

BACKGROUND: Data regarding the association between sleep apnea (SA) and atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) are still limited. We aim to investigate the association of both types of SA, obstructive sleep apnea (OSA) and central sleep apnea (CSA), and nocturnal hypoxemia with AF in HCM. METHODS: A total of 606 patients with HCM who underwent sleep evaluations were included. Logistic regression was used to assess the association between sleep disorder and AF. RESULTS: SA was presented in 363 (59.9%) patients, of whom 337 (55.6%) had OSA and 26 (4.3%) had CSA. Patients with SA were older, more often male, had a higher body mass index, and more clinical comorbidities. Prevalence of AF was higher in patients with CSA than patients with OSA and without SA (50.0% versus 24.9% and 12.8%, p < 0.001). After adjustment for age, sex, body mass index, hypertension, diabetes mellitus, cigarette use, New York Heart Association class and severity of mitral regurgitation, SA (OR, 1.79; 95% CI, 1.09-2.94) and nocturnal hypoxemia (higher tertile of percentage of total sleep time with oxygen saturation < 90% [OR, 1.81; 95% CI, 1.05-3.12] compared with lower tertile) were significantly associated with AF. The association was much stronger in the CSA group (OR, 3.98; 95% CI, 1.56-10.13) than in OSA group (OR, 1.66; 95% CI, 1.01-2.76). Similar associations were observed when analyses were restricted to persistent/permanent AF. CONCLUSION: Both types of SA and nocturnal hypoxemia were independently associated with AF. Attention should be paid to the screening of both types of SA in the management of AF in HCM.

Injectable hydrogel encapsulated with VEGF-mimetic peptide-loaded nanoliposomes promotes peripheral nerve repair in vivo.

Repair of peripheral nerve crush injury remains a major clinical challenge. Currently, oral or intravenous neurotrophic drugs are the main treatment for peripheral nerve crush injury; however, this repair process is slow, and the final effect may be uncertain. The current study aimed at developing an injectable hydrogel with vascular endothelial growth factor (VEGF)-mimetic peptide (QK)-encapsulated nanoliposomes (QK-NLs@Gel) for sustainable drug release that creates an appropriate microenvironment for nerve regeneration. The QK-encapsulated nanoliposomes (QK-NLs) could facilitate the proliferation, migration, and tube formation capacities of human umbilical vein endothelial cells through the VEGF signaling pathway. The QK-NLs@Gel hydrogel encapsulated with QK-NLs showed enhanced physical properties and appropriate biocompatibility in vitro. Thereafter, the QK-NLs@Gel hydrogel was directly injected into the site of peripheral nerve crush injury in a rat model, where it enhanced revascularization and promoted the M2-polarization of the macrophages, thus providing an optimized microenvironment for nerve regeneration. At four weeks post-surgery, the QK-NLs@Gel injected rats exhibited enhanced axon regeneration, remyelination, and better functional recovery in comparison with other groups in vivo. Overall, these findings demonstrate that the composite hydrogel could promote a multicellular pro-regenerative microenvironment at the peripheral nerve injury site, thus revealing great potential for peripheral nerve restoration. STATEMENT OF SIGNIFICANCE: Peripheral nerve injury (PNI) is a leading public health issue, and how to delivery beneficial drugs to injured sites efficiently is still a big challenge. In the current study, an injectable hydrogel with VEGF-mimetic peptide (QK)-encapsulated nanoliposomes (QK-NLs@Gel) was first developed and used to repair a rat crush injury model. Our results showed that QK-NLs promoted the proliferation, migration, and angiogenesis of HUVEC via VEGF signaling pathway in vitro. Furthermore, when injected to the crushed sites in vivo, the QK-NLs@Gel hydrogel could accelerate nerve repair through enhanced revascularization and M2-polarization of macrophages. These results collectively demonstrate that injection of QK-NLs@Gel hydrogel could create an appropriate microenvironment for peripheral nerve regeneration. This strategy is effective, economical, and convenient for clinical applications.

Prognostic factors and treatment considerations of submandibular gland carcinomas: A population-based study.

OBJECTIVES: The therapeutic regimen of submandibular gland carcinoma (SGC) has not reached consensus, especially for the neck treatment of patients with cN0. MATERIALS AND METHODS: Patients with SGC were identified from the medical database of Shanghai Ninth People's Hospital. Kaplan-Meier analysis, univariate and multivariate Cox regression were employed to evaluate the survival and independent prognostic factors. RESULTS: Two hundred and fifteen patients with SGC were retrospectively reviewed. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 71.5% and 77.8%, respectively. Multivariate analysis revealed that histological grade, cT classification, cN classification, and perineural invasion (PNI) were independent prognostic factors for DFS, while histological grade, cT classification, cN classification, and age were those for OS. The neck dissection showed no significant survival benefit for patients with cN0. Lung was the most common site of distant metastasis (16.7%). CONCLUSIONS: Histological grade, cT classification, cN classification, age, and PNI were independent prognostic factors of patient with SGC, which should be the main considerations for making therapeutic regimens. Our study also verifies the neck dissection of patient with cN0 is unnecessary, and postoperative radiotherapy (PORT) is vital for patients with pN+.

Carcinoma ex pleomorphic adenoma of the submandibular gland: A retrospective analysis of 86 patients.

OBJECTIVES: To evaluate the prognostic and locoregional metastatic features of carcinoma ex pleomorphic adenoma of submandibular gland (SMG-CXPA) and improve the understanding of this uncommon condition. PATIENTS AND METHODS: We retrospectively reviewed patients who were diagnosed with SMG-CXPA. The survival data of SMG-CXPA patients were statistically analyzed using Cox regression and Kaplan-Meier method. The associations between cervical metastasis and clinicopathological parameters were evaluated using chi-squared test. Additionally, two different histological categories (histological grade and invasiveness) and their combination were evaluated with the Kaplan-Meier method and receiver operating characteristic curves. RESULTS: In total, 86 patients were diagnosed: 38 clinically node-negative, 31 pathologically node-negative, and 17 node-positive patients. Clinical tumor stage and histological grade were two independent prognostic factors for SMG-CXPA. There were significant correlations between sex, tumor size, clinical tumor stage, clinical lymph node stage, histological grade, invasiveness, malignant components, perineural invasion, and no specific criteria exist for the clinical outcome. CONCLUSION: SMG-CXPA is a high-grade malignancy with an unfavorable prognosis. Elective neck dissection should be performed in SMG-CXPA patients with a risk of locoregional metastasis. Histological grade seems to be a more valuable predictor of lymph node involvement than invasiveness.

Recurrent pleomorphic adenoma of the parotid gland: A population-based study with emphasis on re-recurrence and malignant transformation.

BACKGROUND: This study aimed to analyze the prognostic determinants for re-recurrence and malignant transformation of parotid recurrent pleomorphic adenoma (RPA). METHODS: Between January 2011 and December 2020, all the cases of RPA of the parotid gland at our single institution were reviewed. RESULTS: A total of 168 patients were included in this study, with a median age of 41.5 years, and 20 (11.9%) patients developed re-recurrence during follow-up. It has been evidenced that recurrence times (single or multiple) was an independent prognostic factor for recurrence-free survival (p = 0.0264). A total of 26 (15.48%) patients experienced malignant transformation of parotid RPA, and older age (>45 year old), male sex, and higher clinical tumor staging (T3-T4) were significantly associated with malignant transformation of parotid RPA. CONCLUSIONS: Recurrence times was an independent prognostic factor for re-recurrence of parotid RPA, and older male with high T-stage may more easily develop malignant transformation.