354 research outputs found
Células Germinativas E Espermatogênese Do Lagarto Tropidurus Torquatus (tropiduridae) De Uma área Urbana No Bioma Cerrado Do Centro-oeste Brasileiro
Tropidurus comprises a Neotropical genus of lizard that currently has about 30 species widely distributed in the South American. Among these species, Tropidurus torquatus, which has the characteristic of great physiological plasticity, occupying a variety of habitats in open areas and urbanized environments. Considering this, the aim of the study was to investigate the germinative cells and spermatogenesis of a population of T. torquatus in an urban area under Cerrado Biome influences to understand how to establish the temporal development of germinative cells and spermatogenesis during a period of one year. Individuals were obtained in the Zoological Collection of Vertebrates at the Universidade Federal de Mato Grosso (UFMT), and the germinative cells and full spermatogenesis were described with light microscopy. Tropidurus torquatus presented germ cells with similar characteristics already documented for the other species of lizards and reptiles. Spermatogonia type A and B, primary and secondary spermatocytes, and spermatids were present in almost all months evaluated. The gonadosomatic ratio presented its highest value in October, moment in which spermatogenesis presented all the germinative cells and spermatozoa in the lumen, of the seminiferous tubules. In the seasonal climate of the Cerrado Biome, we observe discontinuous spermatogenesis in T. torquatus with the production of spermatozoa in almost every month of the year, however with sperm storage in the epididymis during the phase of testicular regression. © 2016, Universidade Federal de Uberlandia. All rights reserved.3261595160
Laryngeal Dysplasia and narrow band imaging: secondary analysis of published data supports the role in patient follow up
Background: Clinicians have recognised the role of narrow band imaging (NBI) in the management of head and neck cancer in several studies. However, a recent systematic review was unable to pool the data on diagnostic efficacy in this setting owing to the heterogeneity in the published data.
Methods: Secondary analysis of data, utilising Bayes’ theorem, from meta‐analyses and randomised trials
Results: In patients with a histological diagnosis of mild dysplasia who show no abnormalities on NBI, the post‐test probability of malignancy is 2.3%, compared to 10.3% with conventional white light imaging (WLI). For severe dysplasia, similar post‐test probabilities after NBI and WLI are 8.0% and 29.7% respectively. Post‐test probabilities in this setting indicate the chance of missing malignancy following a negative NBI or WLI in patients who undergo no further intervention. This paper also provides a nomogram designed for use in this setting.
Conclusions: This paper identifies the evidence base for use of NBI in the follow up for laryngeal dysplasia
Xevinapant plus radiotherapy in resected, high-risk, cisplatin-ineligible LA SCCHN:the phase III XRay Vision study design
There is a significant unmet need and lack of treatment options for patients with resected, high-risk, cisplatin-ineligible locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). Xevinapant, a first-in-class, potent, oral, small-molecule IAP inhibitor, is thought to restore cancer cell sensitivity to chemotherapy and radiotherapy in clinical and preclinical studies. We describe the design of XRay Vision (NCT05386550), an international, randomized, double-blind, phase III study. Approximately 700 patients with resected, high-risk, cisplatin-ineligible LA SCCHN will be randomized 1:1 to receive 6 cycles of xevinapant or placebo, in combination with radiotherapy for the first 3 cycles. The primary end point is disease-free survival, and secondary end points include overall survival, health-related quality of life, and safety.</p
Circulating tumour DNA detects somatic variants contributing to spatial and temporal intratumural heterogeneity in head and neck squamous cell carcinoma
Background: As circulating tumour DNA (ctDNA) liquid biopsy analysis is increasingly incorporated into modern oncological practice, establishing the impact of genomic intra-tumoural heterogeneity (ITH) upon data output is paramount. Despite advances in other cancer types the evidence base in head and neck squamous cell carcinoma (HNSCC) remains poor. We sought to investigate the utility of ctDNA to detect ITH in HNSCC.Methods: In a pilot cohort of 9 treatment-naïve HNSCC patients, DNA from two intra-tumoural sites (core and margin) was whole-exome sequenced. A 9-gene panel was designed to perform targeted sequencing on pre-treatment plasma cell-free DNA and selected post-treatment samples.Results: Rates of genomic ITH among the 9 patients was high. COSMIC variants from 19 TCGA HNSCC genes demonstrated an 86.9% heterogeneity rate (present in one tumour sub-site only). Across all patients, cell-free DNA (ctDNA) identified 12.9% (range 7.5-19.8%) of tumour-specific variants, of which 55.6% were specific to a single tumour sub-site only. CtDNA identified 79.0% (range: 55.6-90.9%) of high-frequency variants (tumour VAF>5%). Analysis of ctDNA in serial post-treatment blood samples in patients who suffered recurrence demonstrated dynamic changes in both tumour-specific and acquired variants that predicted recurrence ahead of clinical detection.Conclusion: We demonstrate that a ctDNA liquid biopsy identified spatial genomic ITH in HNSCC and reliably detected high-frequency driver mutations. Serial sampling allowed post-treatment surveillance and early identification of treatment failure
Recommendations for head and neck surgical oncology practice in a setting of acute severe resource constraint during the COVID-19 pandemic: an international consensus.
Results and lessons learnt from the WISTERIA phase I trial combining AZD1775 with cisplatin pre- or post-operatively in head and neck cancer
Background: Pre-clinical studies suggest AZD1775, a WEE1 kinase inhibitor, potentiates the activity of various chemotherapeutic agents. Methods: WISTERIA was a prospective, parallel two-group, open-label, dose-finding, phase I clinical trial. Eligible patients had histologically confirmed oral, laryngeal, or hypopharyngeal squamous cell carcinoma, ECOG performance status 0/1, and aged ≥18-to-≤70 years. Primary outcomes were adverse events and defining recommended dose and schedule of AZD1775 in combination with cisplatin in pre-operative (Group A), or with cisplatin/radiotherapy in post-operative (Group B) patients. Dose determination was guided by a modified time-to-event continual reassessment method (mTITE-CRM). Results: Between 30-Oct-2017 and 15-Jul-2019, nine patients were registered: Three into Group A and six into Group B. WISTERIA was closed early due to poor recruitment. Five dose-limiting toxicities (DLTs) were reported in four Group B patients. Seven serious adverse events were reported in four patients: One in Group A, and three in Group B. Three were related to treatment. No treatment-related deaths were reported. Conclusions: WISTERIA did not complete its primary objectives due to poor recruitment and toxicities reported in Group B. However, use of the novel mTITE-CRM improved flexibility in reducing accrual suspension periods and should be considered for future trials in complex patient populations. Clinical Trial Registration: ISRCTN7629195
Second-look PET-CT following an initial incomplete PET-CT response to (chemo)radiotherapy for head and neck squamous cell carcinoma
OBJECTIVES:
The limited positive predictive value of an incomplete response on PET-CT following (chemo)radiotherapy for head and neck squamous cell carcinoma (HNSCC) means that the optimal management strategy remains uncertain. The aim of the study is to assess the utility of a 'second-look' interval PET-CT.
METHODS:
Patients with HNSCC who were treated with (chemo)radiotherapy between 2008 and 2017 and underwent (i) baseline and (ii) response assessment PET-CT and (iii) second-look PET-CT following incomplete (positive or equivocal scan) response were included. Endpoints were conversion rate to complete response (CR) and test characteristics of the second-look PET-CT.
RESULTS:
Five hundred sixty-two patients with HNSCC underwent response assessment PET-CT at a median of 17 weeks post-radiotherapy. Following an incomplete response on PET-CT, 40 patients underwent a second-look PET-CT at a median of 13 weeks (range 6-25) from the first response PET-CT. Thirty-four out of 40 (85%) patients had oropharyngeal carcinoma. Twenty-four out of 40 (60%) second-look PET-CT scans converted to a complete locoregional response. The primary tumour conversion rate was 15/27 (56%) and the lymph node conversion rate was 14/19 (74%). The sensitivity, specificity, positive predictive value and negative predictive value (NPV) of the second-look PET-CT were 75%, 75%, 25% and 96% for the primary tumour and 100%, 92%, 40% and 100% for lymph nodes. There were no cases of progression following conversion to CR in the primary site or lymph nodes.
CONCLUSIONS:
The majority of patients who undergo a second-look PET-CT convert to a CR. The NPV of a second-look PET-CT is high, suggesting the potential to avoid surgical intervention.
KEY POINTS:
• PET-CT is a useful tool for response assessment following (chemo)radiotherapy for head and neck squamous cell carcinoma. • An incomplete response on PET-CT has a limited positive predictive value and optimal management is uncertain.
• These data show that with a 'second-look' interval PET-CT, the majority of patients convert to a complete metabolic response. When there is doubt about clinical and radiological response, a 'second-look' PET-CT can be used to spare patients unnecessary surgical intervention
Malignancy risk analysis in patients with inadequate fine needle aspiration cytology (FNAC) of the thyroid
Background
Thyroid fine needle aspiration cytology (FNAC) is the standard diagnostic modality for thyroid nodules. However, it has limitations among which is the incidence of non-diagnostic results (Thy1). Management of cases with repeatedly non-diagnostic FNAC ranges from simple observation to surgical intervention. We aim to evaluate the incidence of malignancy in non-diagnostic FNAC, and the success rate of repeated FNAC. We also aim to evaluate risk factors for malignancy in patients with non-diagnostic FNAC.
Materials and Methods
Retrospective analyses of consecutive cases with thyroid non diagnostic FNAC results were included.
Results
Out of total 1657 thyroid FNAC done during the study period, there were 264 (15.9%) non-diagnostic FNAC on the first attempt. On repeating those, the rate of a non-diagnostic result on second FNAC was 61.8% and on third FNAC was 47.2%. The overall malignancy rate in Thy1 FNAC was 4.5% (42% papillary, 42% follicular and 8% anaplastic), and the yield of malignancy decreased considerably with successive non-diagnostic FNAC. Ultrasound guidance by an experienced head neck radiologist produced the lowest non-diagnostic rate (38%) on repetition compared to US guidance by a generalist radiologist (65%) and by non US guidance (90%).
Conclusions
There is a low risk of malignancy in patients with a non-diagnostic FNAC result, commensurate to the risk of any nodule. The yield of malignancy decreased considerably with successive non-diagnostic FNAC
A Fully Automated and Explainable Algorithm for the Prediction of Malignant Transformation in Oral Epithelial Dysplasia
Oral epithelial dysplasia (OED) is a premalignant histopathological diagnosis
given to lesions of the oral cavity. Its grading suffers from significant
inter-/intra- observer variability, and does not reliably predict malignancy
progression, potentially leading to suboptimal treatment decisions. To address
this, we developed a novel artificial intelligence algorithm that can assign an
Oral Malignant Transformation (OMT) risk score, based on histological patterns
in the in Haematoxylin and Eosin stained whole slide images, to quantify the
risk of OED progression. The algorithm is based on the detection and
segmentation of nuclei within (and around) the epithelium using an in-house
segmentation model. We then employed a shallow neural network fed with
interpretable morphological/spatial features, emulating histological markers.
We conducted internal cross-validation on our development cohort (Sheffield; n
= 193 cases) followed by independent validation on two external cohorts
(Birmingham and Belfast; n = 92 cases). The proposed OMTscore yields an AUROC =
0.74 in predicting whether an OED progresses to malignancy or not. Survival
analyses showed the prognostic value of our OMTscore for predicting malignancy
transformation, when compared to the manually-assigned WHO and binary grades.
Analysis of the correctly predicted cases elucidated the presence of
peri-epithelial and epithelium-infiltrating lymphocytes in the most predictive
patches of cases that transformed (p < 0.0001). This is the first study to
propose a completely automated algorithm for predicting OED transformation
based on interpretable nuclear features, whilst being validated on external
datasets. The algorithm shows better-than-human-level performance for
prediction of OED malignant transformation and offers a promising solution to
the challenges of grading OED in routine clinical practice
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