80 research outputs found
Uterine sarcoma – current perspectives
Uterine sarcomas comprise a group of rare tumors with differing tumor biology, natural history and response to treatment. Diagnosis is often made following surgery for presumed benign disease. Currently, preoperative imaging does not reliably distinguish between benign leiomyomas and other malignant pathology. Uterine leiomyosarcoma is the most common sarcoma, but other subtypes include endometrial stromal sarcoma (low grade and high grade), undifferentiated uterine sarcoma and adenosarcoma. Clinical trials have shown no definite survival benefit of adjuvant radiotherapy or chemotherapy and have been hampered by the rarity and heterogeneity of these disease types. There is a role of adjuvant treatment in carefully selected cases following multidisciplinary discussion at sarcoma reference centers. In patients with metastatic disease, systemic chemotherapy can then be considered. There is activity of a number of agents, including doxorubicin, trabectedin, gemcitabine-based chemotherapy, eribulin and pazopanib. Patients should be considered for clinical trial entry where possible. Close international collaboration is important to allow progress in this group of diseases
Toxicity, normal tissue and dose-volume planning parameters for radiotherapy in soft tissue sarcoma of the extremities: A systematic review of the literature
BACKGROUND:
Patients with soft tissue sarcoma of the extremities (STSE) are left with high incidence of toxicities after Radiotherapy (RT). Understanding the normal tissue dose relationship with the development of long-term toxicities may enable better RT planning in order to reduce treatment toxicities for STSE. This systematic review of the literature aims at reporting the incidence of acute and late toxicities and identifying RT delineation guidance the normal tissues structures and dose-volume parameters for STSE.
METHODS:
A literature search of PUBMED-MEDLINE for studies that reported data on RT toxicity outcomes, delineation guidelines and dose-volume parameters for STSE from 2000 to 2022. Data has been tabulated and reported.
RESULTS:
Thirty of 586 papers were selected after exclusion criteria. External beam RT prescriptions ranged from 30 to 72 Gy. The majority of studies reported the use of Intensity Modulated RT (IMRT) (27%). Neo-adjuvant RT was used in 40%. The highest long-term toxicities were subcutaneous and lymphoedema, reported when delivering 3DCRT. IMRT had a lower incidence of toxicities. Normal tissue outlining such as weight-bearing bones, skin and subcutaneous tissue, corridor and neurovascular bundle was recommended in 6 studies. Nine studies recommended the use of dose-volume constraints, but only one recommended evidence-based dose-volume constraints.
CONCLUSION:
Although the literature is replete with toxicity reports, there is a lack of evidence-based guidance on normal tissue and dose-volume parameters and strategies to reduce the normal tissues irradiation when optimising RT plans for STSE are poor compared to other tumour sites
Effects of deforestation on physicochemical properties and microbial population of soils in a South-East Asian tropical forest
The study was conducted in deforested land and adjacent natural forest in Chittagong Forest South Division, Bangladesh, to explore the effects of deforestation on physico-chemical properties of soil and the soil microbial population. Soil samples from surface (0-10 cm depth) or subsurface (10-20 cm depth) of two hill positions (top and bottom) of deforested land and an adjacent natural forest were collected and analysed for their physico-chemical properties and microbial population. The study reveals that there was no significant (p≤0.05) difference in soil texture for soil surfaces or hill positions between the deforested land and natural forest. However, significantly (p≤0.05) low moisture content and high pH was observed in both the surfaces and hill position in deforested land compared to the natural forest. The microbial community i.e., the fungal and bacterial population was also significantly (p≤0.05) lower in both surfaces (0-10 cm and 10-20 cm) of hill positions in the deforested land compared to natural forest. Fungal population ranged from 59 to 76 million g-1 and 78 to 153 million g-1 of dry soil in deforested land and in natural forest, respectively, whereas bacterial population ranged from 70 to 146 million g-1 in deforested land and from 127 to 218 million g-1 in natural forest. A total of seven genera of fungi were primarily identified from the soils of natural forest and six from the deforested land. The six common genera of identified fungi in both the land used were Mucor, Aspergillus, Rhizopus, Fusarium, Penicillium and Trichoderma and the different one was Colletotrichum from the natural forest. Three genera of bacteria coccus, Streptococcus and Basillus were noticed in natural forest and two genera (coccus and Streptococcus) were recorded from deforested land
Rare Aggressive Behavior of <i>MDM2</i>-Amplified Retroperitoneal Dedifferentiated Liposarcoma, with Brain, Lung and Subcutaneous Metastases.
Dedifferentiated liposarcoma (DDL) is a histologically pleomorphic sarcoma, traditionally defined as well-differentiated liposarcoma with abrupt transition to high grade, non-lipogenic sarcoma. It can occur as part of recurrent well-differentiated liposarcoma, or may arise de novo. DDL most frequently occurs within the retroperitoneum, and while it is prone to local recurrence, it usually has a lower rate of metastasis than other pleomorphic sarcomas. We describe a case of retroperitoneal dedifferentiated liposarcoma in a 63-year-old male, who showed MDM2 amplification with fluorescence in situ hybridization, which displayed unusually aggressive behavior, with brain, lung and subcutaneous soft tissue metastases. As previous reports of metastatic liposarcoma have largely grouped DDL in with other (genetically and clinically distinct) liposarcoma subtypes, we highlight and discuss the rare occurrence of brain metastasis in MDM2-amplified retroperitoneal liposarcoma
Recovery of Salivary Function: Contralateral Parotid-sparing Intensity-modulated Radiotherapy versus Bilateral Superficial Lobe Parotid-sparing Intensity-modulated Radiotherapy.
Aims To establish whether there is a difference in recovery of salivary function with bilateral superficial lobe parotid-sparing intensity-modulated radiotherapy (BSLPS-IMRT) versus contralateral parotid-sparing IMRT (CLPS-IMRT) in patients with locally advanced head and neck squamous cell cancers.Materials and methods A dosimetric analysis was carried out on data from two studies in which patients received BSLPS-IMRT (PARSPORT II) or CLPS-IMRT (PARSPORT). Acute (National Cancer Institute, Common Terminology Criteria for adverse events - NCI CTCAEv3.0) and late (Late Effects of Normal Tissue- subjective, objective, management analytical - LENTSOMA and Radiation Therapy Oncology Group) xerostomia scores were dichotomised: recovery (grade 0-1) versus no recovery (≥grade 2). Incidence of recovery of salivary function was compared between the two techniques and dose-response relationships were determined by fitting dose-response curves to the data using non-linear logistic regression analysis.Results Seventy-one patients received BSLPS-IMRT and 35 received CLPS-IMRT. Patients received 65 Gy in 30 fractions to the primary site and involved nodal levels and 54 Gy in 30 fractions to elective nodal levels. There were significant differences in mean doses to contralateral parotid gland (29.4 Gy versus 24.9 Gy, P < 0.005) and superficial lobes (26.8 Gy versus 30.5 Gy, P = 0.02) for BSLPS and CLPS-IMRT, respectively. Lower risk of long-term ≥grade 2 subjective xerostomia (LENTSOMA) was reported with BSLPS-IMRT (odds ratio 0.50; 95% confidence interval 0.29-0.86; P = 0.012). The percentage of patients who reported recovery of parotid saliva flow at 1 year was higher with BSLPS-IMRT compared with CLPS-IMRT techniques (67.1% versus 52.8%), but the difference was not statistically significant (P = 0.12). For the whole parotid gland, the tolerance doses, D50, were 25.6 Gy (95% confidence interval 20.6-30.5), k = 2.7 (0.9-4.5) (CLPS-IMRT) and 28.9 Gy (26.1-31.9), k = 2.4 (1.4-3.4) (BSLPS-IMRT). For the superficial lobe, D50 were similar: BSLPS-IMRT 23.5 Gy (19.3-27.6), k = 1.9 (0.5-3.8); CLPS-IMRT 24.0 Gy (17.7-30.1), k = 2.1 (0.1-4.1).Conclusion BSLPS-IMRT reduces the risk of developing high-grade subjective xerostomia compared with CLPS-IMRT. The D50 of the superficial lobe may be a more reliable predictor of recovery of parotid function than the whole gland mean dose
OX40 and 4-1BB delineate distinct immune profiles in sarcoma.
Systemic relapse after radiotherapy and surgery is the major cause of disease-related mortality in sarcoma patients. Combining radiotherapy and immunotherapy is under investigation as a means to improve response rates. However, the immune contexture of sarcoma is understudied. Here, we use a retrospective cohort of sarcoma patients, treated with neoadjuvant radiotherapy, and TCGA data. We explore therapeutic targets of relevance to sarcoma, using genomics and multispectral immunohistochemistry to provide insights into the tumor immune microenvironment across sarcoma subtypes. Differential gene expression between radioresponsive myxoid liposarcoma (MLPS) and more radioresistant undifferentiated pleomorphic sarcoma (UPS) indicated UPS contained higher transcript levels of a number of immunotherapy targets (CD73/NT5E, CD39/ENTPD1, CD25/IL2RA, and 4-1BB/TNFRSF9). We focused on 4-1BB/TNFRSF9 and other costimulatory molecules. In TCGA data, 4-1BB correlated to an inflamed and exhausted phenotype. OX40/TNFRSF4 and 4-1BB/TNFRSF9 were highly expressed in sarcoma subtypes versus other cancers. Despite OX40 and 4-1BB being described as Treg markers, we identified that they delineate distinct tumor immune profiles. This was true for sarcoma and other cancers. While only a limited number of samples could be analyzed, spatial analysis of OX40 expression identified two diverse phenotypes of OX40+ Tregs, one associated with and one independent of tertiary lymphoid structures (TLSs). Patient stratification is of intense interest for immunotherapies. We provide data supporting the viewpoint that a cohort of sarcoma patients, appropriately selected, are promising candidates for immunotherapies. Spatial profiling of OX40+ Tregs, in relation to TLSs, could be an additional metric to improve future patient stratification
Intensity modulated radiotherapy in locally advanced thyroid cancer: Outcomes of a sequential phase I dose-escalation study.
BACKGROUND AND PURPOSE:To determine the safety and tolerability of dose-escalation using modestly accelerated IMRT in high-risk locally advanced thyroid cancer requiring post-operative radiotherapy, and to report preliminary data on efficacy. MATERIALS AND METHODS:A sequential Phase I dose-escalation design was used. Dose level one (DL1) received 58.8 Gy/28F to the post-operative bed and 50 Gy/28F to elective nodes. DL2 received 66.6 Gy/30F to the thyroid bed, 60 Gy/30F to post-operative nodal levels and 54 Gy/30F to elective nodal levels. Acute (NCICTCv.2.0) and late toxicities (RTOG and modified LENTSOM) were recorded. The primary endpoint was the number of patients with ≥Grade 3 (G3) toxicity at 12 months post-treatment. RESULTS:Fifteen patients were recruited to DL1 and twenty-nine to DL2. At 12 months ≥G3 toxicities were 8.3% in both DL1 and DL2. At 60 months, ≥G3 toxicity was reported in 3 (33%) patients in DL1 and 1 (7%) in DL2. One patient in DL2 died at 24 months from radiation-induced toxicity. Time to relapse and overall survival rates were higher in DL2, but this was not statistically significant. Dose-escalation using this accelerated regimen can be safely performed with a toxicity profile similar to reported series using conventional doses
Induction Chemotherapy Followed by Chemo-intensity-modulated Radiotherapy for Locally Advanced Nasopharyngeal Cancer.
Aims To determine the toxicity and tumour control rates after chemo-intensity-modulated radiotherapy (chemo-IMRT) for locally advanced nasopharyngeal cancers (LA-NPC).Materials and methods Patients with LA-NPC were enrolled in a trial to receive induction chemotherapy followed by parotid-sparing chemo-IMRT. The primary site and involved nodal levels received 65 Gy in 30 fractions and at risk nodal levels received 54 Gy in 30 fractions. Incidence of ≥grade 2 subjective xerostomia was the primary end point. Secondary end points included incidences of acute and late toxicities and survival outcomes.Results Forty-two patients with American Joint Committee on Cancer stages II (12%), III (26%) and IV (62%) (World Health Organization subtype: I [5%]; II [40%]; III [55%]) completed treatment between January 2006 and April 2010 with a median follow-up of 32 months. Incidences of ≥grade 2 acute toxicities were: dysphagia 83%; xerostomia 76%; mucositis 97%; pain 76%; fatigue 99% and ototoxicity 12%. At 12 months, ≥grade 2 subjective xerostomia was observed in 31%, ototoxicitiy in 13% and dysphagia in 4%. Two year locoregional control was 86.2% (95% confidence interval: 70.0-94.0) with 2 year progression-free survival at 78.4% (61.4-88.6) and 2 year overall survival at 85.9% (69.3-93.9).Conclusions Chemo-IMRT for LA-NPC is feasible with good survival outcomes. At 1 year, 31% experience ≥grade 2 subjective xerostomia
Extended pharmacodynamic responses observed upon PROTAC-mediated degradation of RIPK2.
Proteolysis-Targeting Chimeras (PROTACs) are heterobifunctional small-molecules that can promote the rapid and selective proteasome-mediated degradation of intracellular proteins through the recruitment of E3 ligase complexes to non-native protein substrates. The catalytic mechanism of action of PROTACs represents an exciting new modality in drug discovery that offers several potential advantages over traditional small-molecule inhibitors, including the potential to deliver pharmacodynamic (PD) efficacy which extends beyond the detectable pharmacokinetic (PK) presence of the PROTAC, driven by the synthesis rate of the protein. Herein we report the identification and development of PROTACs that selectively degrade Receptor-Interacting Serine/Threonine Protein Kinase 2 (RIPK2) and demonstrate in vivo degradation of endogenous RIPK2 in rats at low doses and extended PD that persists in the absence of detectable compound. This disconnect between PK and PD, when coupled with low nanomolar potency, offers the potential for low human doses and infrequent dosing regimens with PROTAC medicines
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