Therapy-Related Transcriptional Subtypes in Matched Primary and Recurrent Head and Neck Cancer.

PURPOSE: The genetic relatedness between primary and recurrent head and neck squamous cell carcinomas (HNSCC) reflects the extent of heterogeneity and therapy-driven selection of tumor subpopulations. Yet, current treatment of recurrent HNSCC ignores the molecular characteristics of therapy-resistant tumor populations. EXPERIMENTAL DESIGN: From 150 tumors, 74 primary HNSCCs were RNA sequenced and 38 matched primary/recurrent tumor pairs were both whole-exome and RNA sequenced. Transcriptome analysis determined the predominant classical (CL), basal (BA), and inflamed-mesenchymal (IMS) transcriptional subtypes according to an established classification. Genomic alterations and clonal compositions of tumors were evaluated from whole-exome data. RESULTS: Although CL and IMS subtypes were more common in primary HNSCC with low recurrence rates, the BA subtype was more prevalent and stable in recurrent tumors. The BA subtype was associated with a transcriptional signature of partial epithelial-to-mesenchymal transition (p-EMT) and early recurrence. In 44% of matched cases, the dominant subtype changed from primary to recurrent tumors, preferably from IMS to BA or CL. Expression analysis of prognostic gene sets identified upregulation of hypoxia, p-emt, and radiotherapy resistance signatures and downregulation of tumor inflammation in recurrences compared with index tumors. A relevant subset of primary/recurrent tumor pairs presented no evidence for a common clonal origin. CONCLUSIONS: Our study showed a high degree of genetic and transcriptional heterogeneity between primary/recurrent tumors, suggesting therapy-related selection of a transcriptional subtype with characteristics unfavorable for therapy. We conclude that therapy decisions should be based on genetic and transcriptional characteristics of recurrences rather than primary tumors to enable optimally tailored treatment strategies.

MRI-based delta-radiomics predicts pathologic complete response in high-grade soft-tissue sarcoma patients treated with neoadjuvant therapy.

PURPOSE: In high-grade soft-tissue sarcomas (STS) the standard of care encompasses multimodal therapy regimens. While there is a growing body of evidence for prognostic pretreatment radiomic models, we hypothesized that temporal changes in radiomic features following neoadjuvant treatment ("delta-radiomics") may be able to predict the pathological complete response (pCR). METHODS: MRI scans (T1-weighted with fat-saturation and contrast-enhancement (T1FSGd) and T2-weighted with fat-saturation (T2FS)) of patients with STS of the extremities and trunk treated with neoadjuvant therapy were gathered from two independent institutions (training: 103, external testing: 53 patients). pCR was defined as <5% viable cells. After segmentation and preprocessing, 105 radiomic features were extracted. Delta-radiomic features were calculated by subtraction of features derived from MRI scans obtained before and after neoadjuvant therapy. After feature reduction, machine learning modeling was performed in 100 iterations of 3-fold nested cross-validation. Delta-radiomic models were compared with single timepoint models in the testing cohort. RESULTS: The combined delta-radiomic models achieved the best area under the receiver operating characteristic curve (AUC) of 0.75. Pre-therapeutic tumor volume was the best conventional predictor (AUC 0.70). The T2FS-based delta-radiomic model had the most balanced classification performance with a balanced accuracy of 0.69. Delta-radiomic models achieved better reproducibility than single timepoint radiomic models, RECIST or the peri-therapeutic volume change. Delta-radiomic models were significantly associated with survival in multivariate Cox regression. CONCLUSION: This exploratory analysis demonstrated that MRI-based delta-radiomics improves prediction of pCR over tumor volume and RECIST. Delta-radiomics may one day function as a biomarker for personalized treatment adaptations.

Radiooncological View on Therapy Outcome after Multidisciplinary Treatment of Sinonasal Tumors.

PURPOSE: We report the outcome of a mono-institutional retrospective study of sinonasal carcinoma with the primary focus on GTV (gross tumor volume) and the effect of radiotherapy. METHODS: 53 patients with sinonasal carcinoma and that of the nasal cavity, paranasal sinus or both except lymphoma were included. All patients were treated between 1999 and 2017. For tumor volume delineation, all pre-therapeutic images were fused to the planning CT (computed tomography). RESULTS: The median follow-up was 17 months [0.3-60], the median age 60 years, 35 males and 18 females were included. Squamous cell carcinoma (SCC) (60.4%) was the predominant histology, followed by adenocarcinoma (15.1%). The mean composite OS (overall survival) time was 33.3 ± 3.5 months. There was no significant difference in the 5 y composite OS between tumor localization or radiotherapy setting. The simultaneous integrated boost concept showed a trend towards improving five-year composite OS compared to the sequential boost concept. The only factor with a significant impact on the 5 y composite OS rate was the pre-therapeutic GTV (cutoff 75 cm3; p = 0.033). The GTV ≥ 100 cm3 has no effect on the 5 y composite OS rate for SCC. CONCLUSIONS: The pre-therapeutic GTV is a prognostic factor for five-year composite OS for the entire group of patients with sinonasal tumors, influencing the outcome after completion of all treatment strategies. The GTV seems to not influence five-year composite OS in SCC. For this rare tumor entity, an intensive, multidisciplinary discussion is essential to finding the best treatment option for the patient.

Correlational analysis of the regulatory interplay between molecules and cellular components mediating angiogenesis in wound healing under normal and hyperglycemic conditions.

AIM: The aim of this study was to correlate the content of cells with regulatory molecules associated with angiogenesis in wound healing in a rat model of hyperglycemia. We hypothesize that blood neutrophils are the main VEGF source and can stimulate FLT-1 receptor expression, which is the perquisite for efficient neoangiogenesis. MATERIALS AND METHODS: Kinetic studies of the healing dynamics (3, 7, 14, 21 days) of burn wounds on the skin were conducted in white adult male rats. The content of nuclear factor kappa B (NF-κB), vascular endothelial growth factor (VEGF), its receptor (Flt-1) in the regenerated tissue was analyzed by western blot. Numbers of cells associated with the regenerative process and from peripheral blood (PB) were determined. Additionally a bone marrow (BM) myelogram was conducted. RESULTS: The relative number of peripheral blood (PB) neutrophils was found to be associated with the level of VEGF (R = 0.708) and Flt-1 (R = 0.472). The relative number of fibroblasts was also associated with VEGF (R = 0.562), but not with Flt-1. A negative association was found between the number of neutrophils in the regenerated tissue with VEGF (R = -0.454) and FLT-1 (R = -0.665). This confirms our hypothesis, that blood neutrophils are the main VEGF producer that stimulate the expression of the FLT-1 receptor subsequently inducing neoangiogenesis.Furthermore, that under hyperglycemic conditions fibroblasts were highly associated with VEGF (R = 0.800), while negatively associated with FLT-1 (R = -0.506). There was a high association between PB neutrophils and newly generated tissue cells: neutrophils (R = 0.717) and macrophages (R = 0.622), as well as the association between neutrophils and macrophages (R = 0.798). This is an indication of chronic inflammation and increased transmigration of blood cells to the burned tissue. CONCLUSION: Blood neutrophils are the main producer of VEGF and stimulate the expression of the FLT-1 receptor. In the context of hyperglycemia the imbalance of receptor and ligand associated with angiogenesis indicates for chronic inflammation: VEGF and FLT-1, which facilitates hypoxia, prevents the physiological course of burn wound healing and may be an important factor in impaired tissue regeneration in diabetes.

Prognostic Assessment in High-Grade Soft-Tissue Sarcoma Patients: A Comparison of Semantic Image Analysis and Radiomics.

BACKGROUND: In patients with soft-tissue sarcomas of the extremities, the treatment decision is currently regularly based on tumor grading and size. The imaging-based analysis may pose an alternative way to stratify patients' risk. In this work, we compared the value of MRI-based radiomics with expert-derived semantic imaging features for the prediction of overall survival (OS). METHODS: Fat-saturated T2-weighted sequences (T2FS) and contrast-enhanced T1-weighted fat-saturated (T1FSGd) sequences were collected from two independent retrospective cohorts (training: 108 patients; testing: 71 patients). After preprocessing, 105 radiomic features were extracted. Semantic imaging features were determined by three independent radiologists. Three machine learning techniques (elastic net regression (ENR), least absolute shrinkage and selection operator, and random survival forest) were compared to predict OS. RESULTS: ENR models achieved the best predictive performance. Histologies and clinical staging differed significantly between both cohorts. The semantic prognostic model achieved a predictive performance with a C-index of 0.58 within the test set. This was worse compared to a clinical staging system (C-index: 0.61) and the radiomic models (C-indices: T1FSGd: 0.64, T2FS: 0.63). Both radiomic models achieved significant patient stratification. CONCLUSIONS: T2FS and T1FSGd-based radiomic models outperformed semantic imaging features for prognostic assessment.

The rights of surgeons while working with hiv-infected patients in Ukraine.

OBJECTIVE: Introduction: Surgeons that are working with HIV-infected patients in Ukraine are in a vulnerable state due to the lack of special regulation of this issue in labor, medical law and labor contract, as well as the spread of HIV among the population of the country. The aim of this article is to determine and uncover the content of the rights of surgeons while working with HIV-infected patients in Ukraine. PATIENTS AND METHODS: Materials and Methods: The research materials of the rights of the surgeons that are working with HIV-infected patients consist of national legislation, official explanations of the Social Insurance Fund of Ukraine, statistics on HIV infection. The research methods that have been used are cross-sectoral, complex statistical, analysis and synthesis. In order to obtain the results of the research the norms of medical, labor and civil law have been analyzed. RESULTS: Review: The authors of the article have emphasized and described the rights of surgeons that are working with HIV-infected patients. CONCLUSION: Conclusions: It has been proved that the current system of surgeons' rights needs to be improved. It has been offered: to establish, at the legislative level, the responsibility of the patient with HIV infection to warn a medical employee about his infection in case of surgery or other medical manipulation that leads to contact with blood or other biological materials; to revise and significantly increase the payment of obligatory insurance of surgeons, if they are infected by a patient with HIV infection.

Short and long-term phototoxicity in cells expressing genetic reporters under nanosecond laser exposure.

Nanosecond-duration laser pulses are exploited in a plethora of therapeutic and diagnostic applications, such as optoacoustic imaging. However, phototoxicity effects of pulsed radiation in living cells, in particular those expressing genetic reporters, are not well understood. We established a three-dimensional fluorescent protein expressing cellular model in order to reliably investigate the extent and major exposure parameters responsible for both photobleaching and phototoxicity under pulsed laser exposure, unveiling a variety of possible effects on living cells, from reversible photobleaching to cytotoxicity and cell death. Significant losses of fluorescence levels were identified when exposing the cells to illumination conditions considered safe under common standards for skin exposure in diagnostic imaging applications. Thus, the use of photolabile fluorescent proteins and their in vivo exposure parameters have to be designed carefully for all applications using pulsed nanosecond radiation. In particular, loss of signal due to bleaching may significantly alter signals in longitudinal measurements, making data quantification challenging.

Rb1 haploinsufficiency promotes telomere attrition and radiation-induced genomic instability.

Germline mutations of the retinoblastoma gene (RB1) predispose to both sporadic and radiation-induced osteosarcoma, tumors characterized by high levels of genomic instability, and activation of alternative lengthening of telomeres. Mice with haploinsufficiency of the Rb1 gene in the osteoblastic lineage reiterate the radiation susceptibility to osteosarcoma seen in patients with germline RB1 mutations. We show that the susceptibility is accompanied by an increase in genomic instability, resulting from Rb1-dependent telomere erosion. Radiation exposure did not accelerate the rate of telomere loss but amplified the genomic instability resulting from the dysfunctional telomeres. These findings suggest that telomere maintenance is a noncanonical caretaker function of the retinoblastoma protein, such that its deficiency in cancer may potentiate DNA damage-induced carcinogenesis by promoting formation of chromosomal aberrations, rather than simply by affecting cell-cycle control.

Are mouse lens epithelial cells more sensitive to γ-irradiation than lymphocytes?

In this pilot study we compared for the first time the radiation sensitivity of mouse lens epithelial cells (LECs) and mouse lymphocytes. We freshly prepared LECs and lymphocytes and irradiated them with γ-rays ((137)Cs; doses ranging from 0.25 to 2 Gy). DNA damage and repair were evaluated by alkaline comet assay and γH2AX foci assay. Using the comet assay, we observed a dose-dependent increase in DNA damage in both cell types. The faster formation of single- and double-strand breaks in LECs of C57BL/6 mice at doses below 1 Gy needs to be confirmed in other mouse strains. Immunofluorescence for γH2AX foci showed a higher degree of lesions in LECs from C57BL/6J mice compared to those of JF1 mice and to lymphocytes of both strains. Correspondingly, repair of DNA damage proceeded faster in LECs of C57BL/6J mice compared to LECs of JF1 mice and lymphocytes of both strains. It is obvious that the lymphocytes of both strains repaired DNA lesions more slowly than the corresponding LECs. In conclusion, our results demonstrate that LECs of C57Bl/6 mice show a steeper dose-response than lymphocytes in both types of experiments. It shows that both test systems are able to be used also at doses below 0.25 Gy. The observed difference in DNA repair between the LECs from C57BL/6J mice compared to the LECs from JF1 mice and to the lymphocytes of both strains warrants further experiments to identify the underlying molecular mechanisms.