A novel endoscopic nasopharyngectomy by low-temperature plasma radiofrequency ablation in localized recurrent nasopharyngeal carcinoma

OBJECTIVE

Endoscopic nasopharyngectomy (ENPG) with en bloc resection has been well accepted in resectable localized recurrent nasopharyngeal carcinoma (rNPC), but it is a difficult technique to master for most otorhinolaryngology head and neck surgeons. Ablation surgery is a new and simplified method to remove tumors. We designed a novel method using low-temperature plasma radiofrequency ablation (LPRA) and evaluated the survival benefit.

METHODS

A total of 56 localized rNPC patients were explained in detail and retrospectively analyzed. The surgery method was ablated from the resection margin to the center of the tumor. The postmetastatic overall survival (OS), local relapse-free survival (LRFS) rate, progression-free survival (PFS) and distant metastasis-free survival (DMFS) were analyzed using the Kaplan-Meier method and compared by the log-rank test.

RESULTS

All surgeries were successfully performed without any severe postoperative complications or deaths. The median operation time of ablation and harvested NSFF respectively were 29 min (range, 15-100 min) and 101 min (range, 30-180 min). The average number of hospital days postoperation was 3 days (range, 2-5 days). All cases (100.0%) had radical ablation with negative resection margins. The nasopharyngeal defects were completely re-epithelialized in 54 (96.4%) patients. As of the data cutoff (September 3, 2023), the median follow-up time was 44.3 months (range, 17.1-52.7 months, 95% CI: 40.4-48.2). The 3-year OS, LRFS, PFS and DMFS of the entire cohort were 92.9% (95% CI: 0.862-0.996), 89.3% (95% CI: 0.813-0.973), 87.5% (95% CI: 0.789-0.961), and 92.9% (95% CI: 0.862-0.996), respectively. Cycles of radiotherapy were independent risk factors for OS (p = 0.003; HR, 32.041; 95% CI: 3.365-305.064), LRFS (p = 0.002; HR, 10.762; 95% CI: 2.440-47.459), PFS (p = 0.004; HR, 7.457; 95% CI: 1.925-28.877), and DMFS (p = 0.002; HR, 34.776; 95% CI: 3.806-317.799).

CONCLUSION

Radical endoscopic nasopharyngectomy by using low-temperature plasma radiofrequency ablation is a novel, safe and simplified method to master and disseminate for treating resectable rNPC. However, further data and longer follow-up time are needed to prove its efficacy.

Hyperfractionation compared with standard fractionation in intensity-modulated radiotherapy for patients with locally advanced recurrent nasopharyngeal carcinoma: a multicentre, randomised, open-label, phase 3 trial

BACKGROUND

Reirradiation in standard fractionation for locally advanced recurrent nasopharyngeal carcinoma after a previous course of high-dose radiotherapy is often associated with substantial late toxicity, negating its overall benefit. We therefore aimed to investigate the efficacy and safety of hyperfractionation compared with standard fractionation in intensity-modulated radiotherapy.

METHODS

This multicentre, randomised, open-label, phase 3 trial was done in three centres in Guangzhou, China. Eligible patients were aged 18-65 years with histopathologically confirmed undifferentiated or differentiated, non-keratinising, advanced locally recurrent nasopharyngeal carcinoma. Participants were randomly assigned (1:1) to either receive hyperfractionation (65 Gy in 54 fractions, given twice daily with an interfractional time interval of at least 6 h) or standard fractionation (60 Gy in 27 fractions, given once a day). Intensity-modulated radiotherapy was used in both groups. A computer program generated the assignment sequence and randomisation was stratified by treatment centre, recurrent tumour stage (T2-T3 vs T4), and recurrent nodal stage (N0 vs N1-N2), determined at the time of randomisation. The two primary endpoints were the incidence of severe late complications defined as the incidence of grade 3 or worse late radiation-induced complications occurring 3 months after the completion of radiotherapy until the latest follow-up in the safety population, and overall survival defined as the time interval from randomisation to death due to any cause in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02456506.

FINDINGS

Between July 10, 2015, and Dec 23, 2019, 178 patients were screened for eligibility, 144 of whom were enrolled and randomly assigned to hyperfractionation or standard fractionation (n=72 in each group). 35 (24%) participants were women and 109 (76%) were men. After a median follow-up of 45·0 months (IQR 37·3-53·3), there was a significantly lower incidence of grade 3 or worse late radiation-induced toxicity in the hyperfractionation group (23 [34%] of 68 patients) versus the standard fractionation group (39 [57%] of 68 patients; between-group difference -23% [95% CI -39 to -7]; p=0·023). Patients in the hyperfractionation group had better 3-year overall survival than those in the standard fractionation group (74·6% [95% CI 64·4 to 84·8] vs 55·0% [43·4 to 66·6]; hazard ratio for death 0·54 [95% CI 0·33 to 0·88]; p=0·014). There were fewer grade 5 late complications in the hyperfractionation group (five [7%] nasal haemorrhage) than in the standard fractionation group (16 [24%], including two [3%] nasopharyngeal necrosis, 11 [16%] nasal haemorrhage, and three [4%] temporal lobe necrosis).

INTERPRETATION

Hyperfractionated intensity-modulated radiotherapy could significantly decrease the rate of severe late complications and improve overall survival among patients with locally advanced recurrent nasopharyngeal carcinoma. Our findings suggest that hyperfractionated intensity-modulated radiotherapy could be used as the standard of care for these patients.

FUNDING

Key-Area Research and Development of Guangdong Province, the National Natural Science Foundation of China, the Special Support Program for High-level Talents in Sun Yat-sen University Cancer Center, the Guangzhou Science and Technology Plan Project, and the National Ten Thousand Talents Program Science and Technology Innovation Leading Talents, Sun Yat-Sen University Clinical Research 5010 Program.

Prognostic values of immune scores and immune microenvironment-related genes for hepatocellular carcinoma

It is crucial to grasp the characteristics of tumour immune microenvironment to improve effects of immunotherapy. In this study, the immune and stromal scores of 371 cases were calculated for quantitative analysis of immune and stromal cell infiltration in the tumour microenvironment of hepatocellular carcinoma (HCC). The weighted gene co-expression network analysis and protein–protein interaction network were analysed to identify immune microenvironment-related genes. The results showed that patients with high immune scores had a higher 4-year recurrence-free rate. TP53, CTNNB1, and AXIN1 mutations significantly varied with immune scores. In immune score-related modules analysis, Kyoto encyclopaedia of genes and genomes pathways and gene ontology terms were closely related to immune processes, tumorigenesis, and metastasis. Twelve new immune microenvironment-related genes were identified and had significantly positive correlations with seven immune checkpoint genes. In prognostic analysis, eleven immune microenvironment-related genes exhibited high expression, nine of which were validated in the GSE62232 dataset and were significantly associated with a good prognosis. Our findings suggest that calculating immune score and stromal score could help to determine tumour purity and immune cell infiltration in the tumour microenvironment. Nine immune microenvironment-related genes identified in this study had potential as prognostic markers for HCC.

[The efficacy and safety of linagliptin in elderly patients with type 2 diabetes: a pooled analysis of eight placebo-controlled clinical trials]

Objective: To evaluate the efficacy and safety of dipeptidyl peptidase-4 inhibitor, linagliptin, in subjects aged 60 years or older with type 2 diabetes mellitus (T2DM). Methods: Data from eight 24-week, multinational, multicenter, randomized, double-blind, placebo-controlled, parallel-group studies were analyzed. Patients aged 60 years or older with T2DM were received oral linagliptin (5 mg/d) or placebo in combination with metformin, or metformin plus sulfonylurea. Efficacy was assessed by the changes in glycosylated hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) from baseline to 24 weeks of treatment. Safety endpoint included the frequency and intensity of adverse events. Results: A total of 1 421 patients (placebo 429, linagliptin 992) were included in the full analysis set (FAS). Mean ages of the subjects were (67.4±5.6) years in the linagliptin group and (66.7±5.6) years in the placebo group. Baseline HbA1c was (8.0±0.8) % in the linagliptin group and (8.1±0.9) % in the placebo group. At the end of 24-week, placebo-adjusted reduction in HbA1c in subjects with linagliptin was (0.7±0.1)% (95%CI 0.6-0.8, P<0.000 1), and placebo-adjusted reduction in FPG in subjects with linagliptin was (0.88±0.12) mmol/L(95%CI 0.65-1.11, P<0.000 1). Overall safety and tolerability in the two groups were similar. Adverse events occurred in 57.1% of patients in the placebo group and 61.1% of patients in the linagliptin group, and the incidence of adverse events leading to discontinuation was 3.2% in the placebo group and 3.8% in the linagliptin group. Serious adverse events occurred in 1.6% of patients in the placebo group and 2.8% of patients in the linagliptin group. Investigator-defined hypoglycaemia occurred in 7.3% of patients in the placebo group and 11.9% of patients in the linagliptin group. Among them, most were mild or moderate hypoglycaemia, and severe hypoglycaemia only occurred in 0.2% of patients in the placebo and 0.5% in the linagliptin groups. Overall incidence of hypoglycaemia in linagliptin group was slightly higher than that in placebo group, which might be due to the fact that more patients were taking sulfonylureas in linagliptin group than in placebo group (26.8% linagliptin; 18.4% placebo). No difference could be viewed in hypoglycaemia between the two groups in patients without sulfonylureas (1.2% linagliptin, 1.1% placebo). Moreover, no severe hypoglycaemia was reported in subjects without sulfonylureas. The incidences of other adverse events were similar in both groups. Conclusion: Linagliptin was efficacious in lowering glucose with a safety profile similar to placebo in type 2 diabetic patients aged 60 years or older.

Optimum superimposition of protein structures: ambiguities and implications

BACKGROUND

Techniques for comparison and optimum superimposition of protein structures are indispensable tools, providing the basis for statistical analysis, modeling, prediction and classification of protein folds. Observed similarity of structures is frequently interpreted as an indication of evolutionary relatedness. A variety of advanced techniques are available, but so far the important issue of uniqueness of structural superimposition has been largely neglected. We set out to investigate this issue by implementing an efficient algorithm for structure superimposition enabling routine searches for alternative alignments.

RESULTS

The algorithm is based on optimum superimposition of structures and dynamic programming. The implementation is tested and validated using published results. In particular, an automatic classification of all protein folds in a recent release of the protein data bank is performed. The results obtained are closely related to published data. Surprisingly, for many protein pairs alternative alignments are obtained. These alignments are indistinguishable in terms of number of equivalent residues and root mean square error of superimposition, but the respective sets of equivalent residue pairs are completely distinct. Alternative alignments are observed for all protein architectures, including mixed alpha/beta folds.

CONCLUSIONS

Superimposition of protein folds is frequently ambiguous. This has several implications on the interpretation of structural similarity with respect to evolutionary relatedness and it restricts the range of applicability of superimposed structures in statistical analysis. In particular, studies based on the implicit assumption that optimum superimposition of structures is unique are bound to be misleading.

A differential geometric treatment of protein structure comparison

The technique of model-building a protein of known sequence but unknown tertiary structure from the structures of homologous proteins is probably so far the most reliable means of mapping from primary to tertiary structure. A key step towards the realization of the aim is to develop ways of aligning three-dimensional structures of homologous proteins, thereby deriving the rules useful for protein modelling. We have developed a generalized differential-geometric representation of protein local conformation for use in a protein comparison program which aligns protein sequences on the basis of their sequence and conformational knowledge. Because the differential-geometric distance measure between local conformations is independent of the coordinate frame and remains chirality information, the comparison program is easily implemented, relatively rational and reasonably fast. The utility of this program for aligning closely and distantly related homologous proteins is demonstrated by multiple alignment of globins, serine proteinases and aspartic proteinase domains. Particularly, the method has reached the rational alignment between the mammalian and microbial serine proteinases as compared with many published alignment programs.

Relationship between naturally occurring human antibodies to casein and autologous antiidiotypic antibodies: implications for the network theory

Previous studies on human autologous antiidiotypes have been based largely upon analyses of autoimmune disease. We have previously described polyclonal, naturally occurring human autoantibodies directed against antibodies with specificity toward bovine casein in the sera of IgA-deficient humans. In order to define this system more exactly we have not produced two murine monoclonal antibodies directed against bovine milk kappa-casein to use as clonal tools to identify specific antiidiotypes in these human sera. Kappa-casein is an important part of the casein micelle in milk and cheese; in addition to being an important immunogen for man, kappa-casein is known to have conserved amino acid sequence and two antigenic epitopes. Data presented here show that the serum of up to 74% of IgA-deficient and 10% of normal humans have specific autologous antiidiotypes in their serum which bind to monoclonal antibodies directed to bovine kappa-casein. These human antibodies [intact or F(ab)'2] can be blocked from binding to the monoclonal anti-kappa-caseins by pure bovine kappa-casein or the kappa-casein peptide fragment. In contrast to previous studies in autoimmune disease, serum levels of the autoantiidiotypes were directly proportional to the level of IgG antibody to bovine kappa-casein. These observations suggest that continual exposure to a ubiquitous dietary antigen may produce an antigen driven system in which stimulation of both Ab1 and Ab2 occurs in concert.

[Anti-inflammatory effect of cyproheptadine]

Cyproheptadine, an anti-5-hydroxytryptamine drug, 20 mg/kg ip or 20-40 mg/kg ig markedly inhibited hind paw edema induced by injection of fresh egg white 0.1 ml or 2.5% formaldehyde 0.1 ml in rats. Cyproheptadine 20 mg/kg ip or 40-60 mg/kg ig inhibited hind paw edema produced by local injection of 0.15 ml 1% carrageenin in normal or adrenalectomized rats. It inhibited the proliferation of granuloma induced by cotton pellet after sc 20 mg/kg qd x 7d, the swelling of mouse ear induced by xylene, and the increased vascular permeability induced by 0.7% HAc in mice. Cyproheptadine did not prolong the survival time in adrenalectomized rats and there were no marked effects on adrenal weight or the plasma concentration of cortisol in rats. It decreased the weight of the thymus and the content of prostaglandin E in the inflammatory tissue of rats. These results suggest that the anti-inflammatory activity of cyproheptadine is presumably due to its anti-5-hydroxytryptamine effect and the inhibition of synthesis or release of prostaglandin E.

Production of a monoclonal antibody to bovine kappa-casein

Caseins (including alpha s1, alpha s2, beta, kappa and gamma casein), a family of phosphoproteins which binds to calcium, are the major proteins in mammalian milk. Kappa-casein, in addition to its calcium binding capacities has an important role in the stabilization of the micelle structure of milk. In the course of studies to investigate the immunologic effects of ingested bovine kappa-casein in IgA deficiency, a hybridoma has been produced that secretes a monoclonal antibody, (IgG1 kappa isotype), which is specific for bovine kappa -casein. The antibody has been characterized by ELISA and it has been shown to bind specifically to bovine kappa -casein. In a sandwich radioimmunoassay, as little as 0.3 x 10(-4) nM/ml of kappa-casein. could be detected. This antibody does not bind to other bovine milk proteins, nor to human casein.

[Anti-inflammatory effect of diethylcarbamazine citrate]

Diethylcarbamazine citrate (DEC) at 180-300 mg/kg ip or 560 mg/kg ig inhibited hind paw swelling induced by sc 0.15 ml of carrageenan in normal and adrenalectomized rats. DEC ip 300 mg/kg also inhibited the same swelling induced by sc 2.5% formaldehyde in rats. The proliferation of granuloma induced by cotton-pellets tended to be inhibited by DEC, although not significantly. It inhibited the swelling of mouse ear induced by xylene and the increased vascular permeability induced by ip 0.7% HAC. DEC neither prolonged the survival time in adrenalectomized rats nor increased the weight of the adrenal or plasma cortisol levels in normal rats. DEC decreased the prostaglandin E content in inflammatory tissue, although less than the extent in the indomethacin group. These results indicate that the anti-inflammatory action of DEC is presumably due to the inhibition of synthesis or the release of prostaglandin E, in addition to a possible action mediated by its leukotriene synthesis inhibitor action.

Analysis of a common inheritable idiotype in IgA-deficient sera using monoclonal antibodies

In these studies we describe the production of three mAb raised to an idiotype on an IgG anticasein antibody isolated from the serum of one IgA-deficient blood donor. These are IgM kappa and block the binding of casein Ag to anticasein antibody. Sera of unrelated IgA-deficient donors were tested for the presence of the idiotype; 15 of 56 IgA-deficient sera (25%) contain the anticasein idiotype, whereas 1 of 45 normal sera was positive. Anticasein antibodies as a whole were predominantly of the IgG1 and IgG3 subclass; idiotype-positive anticaseins are predominantly of the IgG1 subclass. For IgA-deficient donors, the relative amount of idiotype-positive anticasein antibody was correlated with the level of anticasein present in the serum. Studies were done to investigate the potential inheritance of the idiotype in families; in three of four families the idiotype was inherited in an apparent autosomal dominant pattern. Our data show that a common cross-reactive idiotype can be detected in the sera of IgA-deficient individuals and their family members. This suggests that V region markers may be conserved in this humoral immunodeficiency disease.

Analysis of a common inheritable idiotype in IgA-deficient sera using monoclonal antibodies

In these studies we describe the production of three mAb raised to an idiotype on an IgG anticasein antibody isolated from the serum of one IgA-deficient blood donor. These are IgM kappa and block the binding of casein Ag to anticasein antibody. Sera of unrelated IgA-deficient donors were tested for the presence of the idiotype; 15 of 56 IgA-deficient sera (25%) contain the anticasein idiotype, whereas 1 of 45 normal sera was positive. Anticasein antibodies as a whole were predominantly of the IgG1 and IgG3 subclass; idiotype-positive anticaseins are predominantly of the IgG1 subclass. For IgA-deficient donors, the relative amount of idiotype-positive anticasein antibody was correlated with the level of anticasein present in the serum. Studies were done to investigate the potential inheritance of the idiotype in families; in three of four families the idiotype was inherited in an apparent autosomal dominant pattern. Our data show that a common cross-reactive idiotype can be detected in the sera of IgA-deficient individuals and their family members. This suggests that V region markers may be conserved in this humoral immunodeficiency disease.