Speed of lung inflation at birth influences the initiation of lung injury in preterm lambs

Gas flow is fundamental for driving tidal ventilation and thus the speed of lung motion, but current bias flow settings to support the preterm lung after birth are without an evidence base. We aimed to determine the role of gas bias flow rates to generate positive pressure ventilation in initiating early lung injury pathways in the preterm lamb. Using slower speeds to inflate the lung during tidal ventilation (gas flow rates 4-6 L/min) did not impact lung mechanics, mechanical power or gas exchange compared to those currently used in clinical practice (8-10 L/min). Speed of pressure and volume change during inflation were faster with higher flow rates. Lower flow rates resulted in less bronchoalveolar fluid protein, better lung morphology and fewer detached epithelial cells. Overall, relative to unventilated fetal controls, there was greater protein change using 8-10 L/min, which was associated with enrichment of acute inflammatory and innate responses. Slowing the speed of lung motion by supporting the preterm lung from birth with lower flow rates than currently used clinically resulted in less lung injury without compromising tidal ventilation or gas exchange.

Novel formylpeptide receptor 1/2 agonist limits hypertension-induced cardiovascular damage

AIMS

Formylpeptide receptors (FPRs) play a critical role in the regulation of inflammation, an important driver of hypertension-induced end-organ damage. We have previously reported that the biased FPR small-molecule agonist, compound17b (Cmpd17b), is cardioprotective against acute, severe inflammatory insults. Here, we reveal the first compelling evidence of the therapeutic potential of this novel FPR agonist against a longer-term, sustained inflammatory insult, i.e. hypertension-induced end-organ damage. The parallels between the murine and human hypertensive proteome were also investigated.

METHODS AND RESULTS

The hypertensive response to angiotensin II (Ang II, 0.7 mg/kg/day, s.c.) was attenuated by Cmpd17b (50 mg/kg/day, i.p.). Impairments in cardiac and vascular function assessed via echocardiography were improved by Cmpd17b in hypertensive mice. This functional improvement was accompanied by reduced cardiac and aortic fibrosis and vascular calcification. Cmpd17b also attenuated Ang II-induced increased cardiac mitochondrial complex 2 respiration. Proteomic profiling of cardiac and aortic tissues and cells, using label-free nano-liquid chromatography with high-sensitivity mass spectrometry, detected and quantified ∼6000 proteins. We report hypertension-impacted protein clusters associated with dysregulation of inflammatory, mitochondrial, and calcium responses, as well as modified networks associated with cardiovascular remodelling, contractility, and structural/cytoskeletal organization. Cmpd17b attenuated hypertension-induced dysregulation of multiple proteins in mice, and of these, ∼110 proteins were identified as similarly dysregulated in humans suffering from adverse aortic remodelling and cardiac hypertrophy.

CONCLUSION

We have demonstrated, for the first time, that the FPR agonist Cmpd17b powerfully limits hypertension-induced end-organ damage, consistent with proteome networks, supporting development of pro-resolution FPR-based therapeutics for treatment of systemic hypertension complications.

Differential effects of physiological agonists on the proteome of platelet-derived extracellular vesicles

Arterial thrombosis manifesting as heart attack and stroke is the leading cause of death worldwide. Platelets are central mediators of thrombosis that can be activated through multiple activation pathways. Platelet-derived extracellular vesicles (pEVs), also known as platelet-derived microparticles, are granular mixtures of membrane structures produced by platelets in response to various activating stimuli. Initial studies have attracted interest on how platelet agonists influence the composition of the pEV proteome. In the current study, we used physiological platelet agonists of varying potencies which reflect the microenvironments that platelets experience during thrombus formation: adenosine diphosphate, collagen, thrombin as well as a combination of thrombin/collagen to induce platelet activation and pEV generation. Proteomic profiling revealed that pEVs have an agonist-dependent altered proteome in comparison to their cells of origin, activated platelets. Furthermore, we found that various protein classes including those related to coagulation and complement (prothrombin, antithrombin, and plasminogen) and platelet activation (fibrinogen) are attributed to platelet EVs following agonist stimulation. This agonist-dependent altered proteome suggests that protein packaging is an active process that appears to occur without de novo protein synthesis. This study provides new information on the influence of physiological agonist stimuli on the biogenesis and proteome landscape of pEVs.

Proteomic profiling of small extracellular vesicles derived from mouse pancreatic cancer and stellate cells: Role in pancreatic cancer

Small extracellular vesicles (sEVs) are cell-derived vesicles evolving as important elements involved in all stages of cancers. sEVs bear unique protein signatures that may serve as biomarkers. Pancreatic cancer (PC) records a very poor survival rate owing to its late diagnosis and several cancer cell-derived proteins have been reported as candidate biomarkers. However, given the pivotal role played by stellate cells (PSCs, which produce the collagenous stroma in PC), it is essential to also assess PSC-sEV cargo in biomarker discovery. Thus, this study aimed to isolate and characterise sEVs from mouse PC cells and PSCs cultured alone or as co-cultures and performed proteomic profiling and pathway analysis. Proteomics confirmed the enrichment of specific markers in the sEVs compared to their cells of origin as well as the proteins that are known to express in each of the culture types. Most importantly, for the first time it was revealed that PSC-sEVs are enriched in proteins (including G6PI, PGAM1, ENO1, ENO3, and LDHA) that mediate pathways related to development of diabetes, such as glucose metabolism and gluconeogenesis revealing a potential role of PSCs in pancreatic cancer-related diabetes (PCRD). PCRD is now considered a harbinger of PC and further research will enable to identify the role of these components in PCRD and may develop as novel candidate biomarkers of PC.

Rapid and in-depth proteomic profiling of small extracellular vesicles for ultralow samples

The integration of robust single-pot, solid-phase-enhanced sample preparation with powerful liquid chromatography-tandem mass spectrometry (LC-MS/MS) is routinely used to define the extracellular vesicle (EV) proteome landscape and underlying biology. However, EV proteome studies are often limited by sample availability, requiring upscaling cell cultures or larger volumes of biofluids to generate sufficient materials. Here, we have refined data independent acquisition (DIA)-based MS analysis of EV proteome by optimizing both protein enzymatic digestion and chromatography gradient length (ranging from 15 to 44 min). Our short 15 min gradient length can reproducibly quantify 1168 (from as little as 500 pg of EV peptides) to 3882 proteins groups (from 50 ng peptides), including robust quantification of 22 core EV marker proteins. Compared to data-dependent acquisition, DIA achieved significantly greater EV proteome coverage and quantification of low abundant protein species. Moreover, we have achieved optimal magnetic bead-based sample preparation tailored to low quantities of EVs (0.5 to 1 µg protein) to obtain sufficient peptides for MS quantification of 1908-2340 protein groups. We demonstrate the power and robustness of our pipeline in obtaining sufficient EV proteomes granularity of different cell sources to ascertain known EV biology. This underscores the capacity of our optimised workflow to capture precise and comprehensive proteome of EVs, especially from ultra-low sample quantities (sub-nanogram), an important challenge in the field where obtaining in-depth proteome information is essential.

Burden and trend of dietary risk-related colorectal cancer in China and its provinces: findings from the Global Burden of Disease Study 2019

OBJECTIVES

The objective of this experiment was to evaluate the spatial pattern and temporal trend of colorectal cancer (CRC) burden attributed to dietary risk factors in China from 1990 to 2019 using data from the Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2019.

METHODS

Numbers and age-standardised rates of deaths, disability-adjusted life years (DALYs) and corresponding average annual percentage change (AAPC) were determined. The joinpoint regression analysis was used to assess the temporal trends of CRC deaths and DALYs from 1990 to 2019.

RESULTS

In China, the number of diet-attributable CRC deaths and DALYs in 2019 were 90.41 (95% uncertainty interval: 65.69, 114.67) and 2234.06 (1609.96, 2831.24) per-1000 population, marking 2.05% and 1.68% annual increases since 1990, respectively. The region with the highest increase in age-standardised rates (ASRs) of diet-related CRC deaths and DALYs was in Taiwan with an AAPC of 2.00% (1.51, 2.48), whereas the highest decline in ASRs of CRC deaths and DALYs was observed in Hong Kong with an AAPC of -0.63% (-0.90, -0.35) (all P < 0.05). Nationally, men suffered higher CRC deaths and DALY burdens attributable to dietary risks than did women. Regarding the specific diet group, diets low in calcium, milk, and whole grains contributed to CRC deaths and DALYs the most.

CONCLUSIONS

Diet is an important contributor to increasing CRC burden in China. Necessary measures should be taken to kerb the growing burden attributed to dietary factors, particularly in males and in regions with middle Socio-demographic Index or lower.

[Role of neoadjuvant rectal score in prognosis and adjuvant chemotherapy decision-making in locally advanced rectal cancer following neoadjuvant short-course radiotherapy and consolidation chemotherapy]

Objectives: To assess the prognostic impact of the neoadjuvant rectal (NAR) score following neoadjuvant short-course radiotherapy and consolidation chemotherapy in locally advanced rectal cancer (LARC), as well as its value in guiding decisions for adjuvant chemotherapy. Methods: Between August 2015 and August 2018, patients were eligible from the STELLAR phase III trial (NCT02533271) who received short-course radiotherapy plus consolidation chemotherapy and for whom the NAR score could be calculated. Based on the NAR score, patients were categorized into low (＜8), intermediate (8-16), and high (＞16) groups. The Kaplan-Meier method, log rank tests, and multivariate Cox proportional hazard regression models were used to evaluate the impact of the NAR score on disease-free survival (DFS). Results: Out of the 232 patients, 24.1%, 48.7%, and 27.2% had low (56 cases), intermediate (113 cases), and high NAR scores (63 cases), respectively. The median follow-up period was 37 months, with 3-year DFS rates of 87.3%, 68.3%, and 53.4% (P＜0.001) for the low, intermediate, and high NAR score groups. Multivariate analysis demonstrated that the NAR score (intermediate NAR score: HR, 3.10, 95% CI, 1.30-7.37, P=0.011; high NAR scores: HR=5.44, 95% CI, 2.26-13.09, P＜0.001), resection status (HR, 3.00, 95% CI, 1.64-5.52, P＜0.001), and adjuvant chemotherapy (HR, 3.25, 95% CI, 2.01-5.27, P＜0.001) were independent prognostic factors for DFS. In patients with R0 resection, the 3-year DFS rates were 97.8% and 78.0% for those with low and intermediate NAR scores who received adjuvant chemotherapy, significantly higher than the 43.2% and 50.6% for those who did not (P＜0.001, P=0.002). There was no significant difference in the 3-year DFS rate (54.2% vs 53.3%, P=0.214) among high NAR score patients, regardless of adjuvant chemotherapy. Conclusions: The NAR score is a robust prognostic indicator in LARC following neoadjuvant short-course radiotherapy and consolidation chemotherapy, with potential implications for subsequent decisions regarding adjuvant chemotherapy. These findings warrant further validation in studies with larger sample sizes.

Cardiomyocyte intercellular signalling increases oxidative stress and reprograms the global- and phospho-proteome of cardiac fibroblasts

Pathological reprogramming of cardiomyocyte and fibroblast proteome landscapes drive the initiation and progression of cardiac fibrosis. Although the secretome of dysfunctional cardiomyocytes is emerging as an important driver of pathological fibroblast reprogramming, our understanding of the downstream molecular players remains limited. Here, we show that cardiac fibroblast activation (αSMA+) and oxidative stress mediated by the secretome of TGFβ-stimulated cardiomyocytes is associated with a profound reprogramming of their proteome and phosphoproteome landscape. Within the fibroblast global proteome there was a striking dysregulation of proteins implicated in extracellular matrix, protein localisation/metabolism, KEAP1-NFE2L2 pathway, lysosomes, carbohydrate metabolism, and transcriptional regulation. Kinase substrate enrichment analysis of phosphopeptides revealed potential role of kinases (CK2, CDK2, PKC, GSK3B) during this remodelling. We verified upregulated activity of casein kinase 2 (CK2) in secretome-treated fibroblasts, and pharmacological CK2 inhibitor TBB (4,5,6,7-Tetrabromobenzotriazole) significantly abrogated fibroblast activation and oxidative stress. Our data provides molecular insights into cardiomyocyte to cardiac fibroblast crosstalk, and the potential role of CK2 in regulating cardiac fibroblast activation and oxidative stress.

Impact of tidal volume strategy at birth on initiating lung injury in preterm lambs

Tidal ventilation is essential in supporting the transition to air-breathing at birth, but excessive tidal volume (VT) is an important factor in preterm lung injury. Few studies have assessed the impact of specific VT levels on injury development. Here, we used a lamb model of preterm birth to investigate the role of different levels of VT during positive pressure ventilation (PPV) in promoting aeration and initiating early lung injury pathways. VT was delivered as 1) 7 mL/kg throughout (VTstatic), 2) begun at 3 mL/kg and increased to a final VT of 7 mL/kg over 3 min (VTinc), or 3) commenced at 7 mL/kg, decreased to 3 mL/kg, and then returned to 7 mL/kg (VTalt). VT, inflating pressure, lung compliance, and aeration were similar in all groups from 4 min, as was postmortem histology and lung lavage protein concentration. However, transient decrease in VT in the VTalt group caused increased ventilation heterogeneity. Following TMT-based quantitative mass spectrometry proteomics, 1,610 proteins were identified in the lung. Threefold more proteins were significantly altered with VTalt compared with VTstatic or VTinc strategies. Gene set enrichment analysis identified VTalt specific enrichment of immune and angiogenesis pathways and VTstatic enrichment of metabolic processes. Our finding of comparable lung physiology and volutrauma across VT groups challenges the paradigm that there is a need to rapidly aerate the preterm lung at birth. Increased lung injury and ventilation heterogeneity were identified when initial VT was suddenly decreased during respiratory support at birth, further supporting the benefit of a gentle VT approach.NEW & NOTEWORTHY There is little evidence to guide the best tidal volume (VT) strategy at birth. In this study, comparable aeration, lung mechanics, and lung morphology were observed using static, incremental, and alternating VT strategies. However, transient reduction in VT was associated with ventilation heterogeneity and inflammation. Our results suggest that rapidly aerating the preterm lung may not be as clinically critical as previously thought, providing clinicians with reassurance that gently supporting the preterm lung maybe permissible at birth.

Mercuric-sulphide based metallopharmaceutical formulation as an alternative therapeutic to combat viral and multidrug-resistant (MDR) bacterial infections

According to the Global Antimicrobial Resistance and Use Surveillance System (GLASS) data, antibiotic resistance escalates more challenges in treatment against communicable diseases worldwide. Henceforth, the use of combinational antimicrobial therapy and metal-conjugated phytoconstituents composites are considered as alternatives. The present study explored the efficacy of mercuric-sulfide-based metallopharmaceutical, Sivanar Amirtham for anti-bacterial, anti-tuberculosis, anti-HIV therapeutics and toxicity profile by haemolytic assay, first of its kind. The anti-bacterial study was performed against both gram-positive and gram-negative pathogens including Staphylococcus aureus (ATCC 29213), Methicillin-resistant Staphylococcus aureus (MRSA: ATCC 43300), Enterococcus faecalis (ATCC 29212), Pseudomonas aeruginosa (PA14) and Vibrio cholerae (MTCC 3905) by agar well diffusion assay, wherein the highest zone of inhibition was identified for MRSA (20.7 mm) and V. cholerae (34.3 mm) at 25 mg/mL. Furthermore, the anti-tuberculosis activity experimented by microtitre alamar blue assay against M. tuberculosis (ATCC 27294) demonstrated significant activity at the concentration range of 12.5-100 µg/mL. Additionally, the anti-HIV efficacy established by the syncytia inhibition method using C8166 cell lines infected with HIV-1IIIB, showed a significant therapeutic effect. The in-vitro toxicity assay proved Sivanar Amirtham to be non-haemolytic and haemocompatible. The physicochemical characterization studies revealed the nano-sized particles with different functional groups and the distinctive metal-mineral complex could be attributed to the multi-site targeting ability. The rationale evidence and scientific validation for the efficacy of Sivanar Amirtham ensures that it could be proposed as an alternative or adjuvant for both prophylactics and therapeutics to overcome HIV infection and antimicrobial resistance as well as the multi-drug resistance challenges.

Methodological and Reporting Quality of Non-Inferiority or Equivalence Designs: A Systematic Review of Trial Characteristics, Design Consideration and Interpretation in Breast Cancer Radiotherapy Trials

PURPOSE/OBJECTIVE(S)

To investigate the methodological and reporting quality of non-inferiority (NI)/equivalence trials of breast cancer radiotherapy and to provide suggestions for future NI/equivalence trials.

MATERIALS/METHODS

Prospective phase III randomized controlled trials (RCTs) comparing different radiation modalities in patients with breast cancer and designed or interpreted as NI/equivalence were identified in PubMed, EMBASE and Cochrane library. Two reviewers independently extracted data on trial characteristics, statistical design assumptions and analysis considerations, primary end point results and conclusions. The relationship between the number of published trials and the year of publication was assessed by simple linear regression. Trials with pre-specified NI margins as absolute risk differences were reevaluated using margins as relative risk differences.

RESULTS

A total of 1490 records were screened and 41 articles published between January 1, 2001 and May 9, 2022 were selected for full text review. A total of 21 trials were included (18 designed as NI and 3 as equivalence). Publication of these trials increased over time (p = 0.023). Trial interventions included dose fractionation (n = 10), partial/whole breast irradiation (n = 8) and tumor bed boost (n = 3). Eleven (52.4%) trials clearly described the non-efficacy benefits. The primary endpoints included 5-year local recurrence (LR) (n = 11), 5-year locoregional recurrence (n = 3), acute/late toxicities (n = 5), 2-year LR and cosmetic outcome (n = 1), and 10-year LR (n = 1). Only seven (33.3%) trials provided justification of the margins. The absolute and relative risk margins were both mentioned in nine (42.9%) trials' methods and reported in six (28.6%) trials' results. The analyzed populations were intention-to-treat (ITT) in 10, both ITT and per-protocol in 9 trials. Seventeen (81%) trials reported confidence interval (CI), with twelve reporting CI that agreed with the type I error used in sample size calculation, but only eight (38.1%) reported p value for NI/equivalence test. Fifteen (71.4%) trials concluded NI/equivalence. Five (23.8%) trials had misleading conclusions (four for not mentioning small sample size insufficient to confirm NI/equivalence and one for inconsistent with the published results). Thirteen (61.9%) trials reported that the protocol's initial accrual target was not met, with ten (47.6%) owing to overestimation of event rates. For trials that met NI only based on absolute margin, three of eight (37.5%) trials were classified as inconclusive with the assumed relative margins.

CONCLUSION

The use of NI/equivalence trials of breast cancer radiotherapy has dramatically increased recently, but there is substantial room for improvement in the methodological and reporting quality of NI/equivalence trials.

Comparison of Supraclavicular Surgery plus Radiotherapy vs. Radiotherapy Alone in Breast Cancer Patients with Synchronous Ipsilateral Supraclavicular Lymph Node Metastasis: A Multicenter Retrospective Study

PURPOSE/OBJECTIVE(S)

To evaluate and compare the outcomes of supraclavicular lymph node dissection (SLND) plus radiotherapy (RT) and RT alone for patients with synchronous ipsilateral supraclavicular lymph node metastasis (sISLM).

MATERIALS/METHODS

In all, 293 patients with sISLM across three centers were included. Of these, 85 (29.0%) received SLND plus RT and 208 (71.0%) received RT alone. All patients received preoperative systemic therapy followed by mastectomy or lumpectomy and axillary dissection. Supraclavicular recurrence-free survival (SCRFS), locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were evaluated by using the Kaplan-Meier method and multivariate Cox models. Multiple imputation was used for missing data.

RESULTS

The median follow-up duration of the RT and SLND+RT groups were 53.7 and 63.5 months, respectively. For the RT and SLND+RT groups, the 5-year SCRFS rates were 91.7% vs. 85.5% (P = 0.522), LRRFS rates were 79.1% vs. 73.1% (P = 0.412), DMFS rates were 60.4 vs. 58.8% (P = 0.708), DFS rates were 57.6% vs. 49.7% (P = 0.291), and OS rates were 71.9% vs. 62.2% (P = 0.272), respectively. There was no significant effect on any outcome when comparing SLND+RT versus RT alone in the multivariate analysis. Based on four risk factors of DFS, patients were classified into three risk groups: the intermediate- and high-risk groups had significantly lower survival outcomes than the low-risk group. SLND+RT did not improve outcomes of any risk group compared with RT alone.

CONCLUSION

Patients with sISLM may not benefit from SLND. Distant metastasis remained the major failure pattern, especially for intermediate- and high-risk groups with sISLM may not benefit from SLND. Distant metastasis remained the major failure pattern, especially for intermediate- and high-risk groups.

Early Cardiotoxicity in Patients Receiving Hypofractionated Radiotherapy after Breast Conserving Surgery: Analysis of a Prospective Study

PURPOSE/OBJECTIVE(S)

To evaluate the early cardiotoxicity of hypofractionated radiotherapy (HFRT) in patients with left-sided breast cancer after breast-conserving surgery, and to investigate the correlation between cardiotoxicity and cardiac dose.

MATERIALS/METHODS

A total of 103 women from 2017 to 2018 who received left-sided whole-breast with or without regional nodal irradiation either using deep inspiration breath-hold (DIBH) or free-breathing (FB) technique were prospectively enrolled. N-terminal pro-B-type natriuretic peptide (NT-proBNP), electrocardiogram, and radionuclide myocardial perfusion imaging were conducted before and after HFRT. Logistic regression analyses were performed to determine the association of cancer treatment, cardiac dose, and cardiovascular risk factors with cardiotoxic effects.

RESULTS

The mean dose (Dmean) of the heart, left anterior descending coronary artery (LAD), left ventricular (LV), and right ventricular (RV) in all patients was 403 cGy, 1685 cGy, 627 cGy, and 444 cGy, respectively. In comparison to FB, DIBH significantly reduced cardiac dose (heart Dmean 250 cGy vs. 570 cGy, LAD Dmean 1250 cGy vs. 2170 cGy, LV Dmean 420 cGy vs. 850 cGy, RV Dmean 260 cGy vs. 650 cGy; all p<0.001). With a median follow-up of 49 months (range, 2-65 months), no patients had clinical cardiac abnormalities or cardiac-related symptoms, but 42 (41%) patients had subclinical cardiac events. Among them, 41 were electrocardiogram changes, and one had LV ejection fraction decreased by 10% compared with the baseline level. Twenty-five (60%) recovered during follow-up, of which 17 (40%) experienced subclinical changes only once. The mean value of NT-proBNP did not change significantly before and after HFRT. In univariate analyses, DIBH technique significantly decreased the risk of subclinical cardiac events compared with FB (OR 0.31, 95% CI 0.14-0.71; p = 0.006); however, higher mean doses of heart and LV, anthracycline-based chemotherapy, obesity, and hypertension were associated with increased risk of subclinical cardiac events (all p<0.05).

CONCLUSION

Early subclinical cardiac damage after HFRT in left-sided breast cancer is dose-related, and mostly manageable and reversible without medical intervention.

Adaptive Ultra-Hypofractionated Whole-Pelvic Radiotherapy in High-Risk and Very High-Risk Prostate Cancer on 1.5-1.5 MR Linac: The Estimated Delivered Dose and Early Toxicity Results

PURPOSE/OBJECTIVE(S)

To study the feasibility and safety for patients with high-risk (HR) and very high-risk (VHR) prostate cancer treated with adaptive ultra-hypofractionated whole-pelvic radiotherapy (UHF-WPRT) on 1.5 magnetic resonance (MR)-Linac.

MATERIALS/METHODS

Sevenpatients with clinical stage T3a-4N0-1M0-1c consecutively treated with UHF-WPRT on a 1.5-T MR-Linac were recruited prospectively in a phase II trial (NCT05183074, ChiCTR2000033382). A 36.25 Gy dose in five fractions was delivered every other day with a boost of 40 Gy to the whole prostate, as well as 25 Gy to whole pelvic nodal area with a concomitant boost of 35 Gy to metastatic regional nodes. To estimate the delivered dose, we collected data by 3D-MR for the following stages: pre-MR, position verification-MR (PV-MR) in the Adapt-To-Shape (ATS) workflow, and 3D-MR during the beam-on phase (Bn-MR) and at the end of RT (post-MR). The target and organ-at-risk contours in the PV-MR, Bn-MR, and post-MR stages were projected from the pre-MR data by deformable image registration and manually adapted by the physician, followed by dose recalculation for the ATS plan. The cumulative acute genitourinary (GU) and gastrointestinal (GI) toxicities were evaluated as per NCI-CTCAE 5.0 criteria. The primary endpoints were acute ≥grade 3 genitourinary (GU) and gastrointestinal (GI) toxicities during the first 3 months.

RESULTS

Overall, 133 MR scans were collected (35 pre-MR, 35 PV-MR, 31 Bn-MR and 32 post-MR scans). With a median on-couch time of 61 minutes, the mean prostate and pelvic planning target volume (PTV)-V95% of all scans was 96.98 ± 3.06% and 96.44 ± 2.85%, respectively. The corresponding mean prostate clinical target volume (CTV)-V100% was 99.89 ± 0.32%, 98.71 ± 1.90%, 97.77 ± 2.89%, and 98.56 ± 1.72%, and the mean pelvic CTV-V100% was 97.57% ± 3.70%, 96.54 ± 3.80%, 95.43 ± 4.31%, and 94.39 ± 4.47% on pre-MR, PV-MR, Bn-MR and post-MR scans, respectively. For the 4 patients with positive nodes, the mean V100% of metastatic regional nodes was 99.89 ± 0.81%. The median V29 Gy change in the rectal wall was -1% (-18%-20%). The V29 Gy of the rectal wall increased by >15% was observed in one scan. A slight increase in the high dose of bladder wall was noted due to gradual bladder growth during the workflow. With median follow-up time of 7.3 (4.6-12.2) months, all patients were followed-up for more than 3 months. No patient was observed with acute CTCAE grade 2 or more severe GU or GI toxicities (0%).

CONCLUSION

UHF-RT to prostate and pelvic with ATS workflow is well tolerated by patients with HR and VHR prostate cancer, with only mild GU and GI toxicities. The 3D-MR-based dosimetry analysis demonstrated clinically acceptable estimated dose coverage of target volumes during the beam-on period.

Lymphocyte Count Kinetics and the Effect of Different Radiotherapy Techniques on Radiation-Induced Lymphopenia in Patients with Breast Cancer Receiving Hypofractionated Postmastectomy Radiotherapy

PURPOSE/OBJECTIVE(S)

Radiation-induced lymphopenia (RIL) is associated with poor prognosis in solid tumors. This study aimed to describe the lymphocyte kinetics in patients with breast cancer receiving hypofractionated postmastectomy radiotherapy (RT) and to investigate the association of different RT techniques with RIL.

MATERIALS/METHODS

We assessed 607 patients who received hypofractionated postmastectomy RT for breast cancer in our prospective clinical database from 8 hospitals. All patients received irradiation to the chest wall and supraclavicular fossa. RT techniques included integrated RT with the photon-based intensity modulated techniques to irradiate all target volumes (integrated RT) and a hybrid approach combining photon irradiation to supraclavicular nodes and electron irradiation to the chest wall (hybrid RT). Peripheral lymphocyte counts (PLC) were tested prior to RT (baseline), weekly during RT, at 1, 2 weeks, 3, 6 months after RT, and then every 6 months. Grade 3+ RIL was defined as PLC nadir during RT of <0.5 ×103/ml. Mean PLC was compared by the t test. Univariate, multivariate, and propensity score matching (PSM) analyses were used to evaluate the effect of different RT techniques on grade 3+ RIL.

RESULTS

During RT, 121 (19.9%) of patients had grade 3+ RIL. The PLC started to recover at 1 week and reached baseline levels 1 year after RT. A greater proportion of the patients treated with the integrated RT (90/269, 33.5%) developed grade 3+ PLC compared with those receiving hybrid RT (31/338, 9.2%, P < 0.001). After conducting PSM, multivariate analyses showed lower baseline PLC (HR = 0.15, P<0.001) and RT technique (the integrated RT vs. hybrid RT, HR = 4.76, P<0.001) were independent risk factors for grade 3+ RIL. The PLC in patients receiving the integrated RT after RT were higher than that in those receiving hybrid RT (p<0.05).

CONCLUSION

RT technique affect the risk of and recovery from RIL, which may impact survival. Choosing appropriate RT technique to minimize RIL might be considered to benefit their outcomes.

Dose-Volume Predictors for Radiation Esophagitis in Breast Cancer Patients Undergoing Hypofractionated Regional Nodal Radiotherapy

PURPOSE/OBJECTIVE(S)

Radiation esophagitis (RE) is often overlooked in breast cancer radiotherapy. This study aimed to assess the incidence and dose-volume predictors of RE in breast cancer patients undergoing hypofractionated regional nodal irradiation (RNI).

MATERIALS/METHODS

Eligible patients were included who received intensity-modulated radiotherapy (RT) at the chest wall, the supraclavicular/infraclavicular fossa, level II axilla, and/or the internal mammary chain after mastectomy. The prescribed dose was 43.5 Gy in 15 fractions. The dose constraint for the esophagus was maximum dose <48 Gy. RE was evaluated weekly during RT and at 1 and 2 weeks, followed by 3 and 6 months after RT, and was graded according to the Common Toxicity Criteria for Adverse Events v3.0. The esophagus was contoured from the lower border level of the cricoid cartilage to the lower margin of the aortic arch. Esophageal total volume, mean dose (Dmean), maximum dose (Dmax), and the relative and absolute volumes receiving at least 5-45 Gy by 5 Gy increments (RV5-RV45 and AV5-AV45) were evaluated. Univariable and multivariable logistics regression analyses were performed to determine risk factors for RE, and receiver operating characteristic curves were obtained to identify the thresholds of esophageal dosimetric parameters.

RESULTS

In total, 298 patients were included between May 8, 2020 and January 5, 2022 (minimum post-RT follow-up: 6 months). A total of 153 (51.3%) patients had left-sided breast cancer and 145 (48.7%) patients received internal mammary nodal irradiation (IMNI). Grade 2 and 3 RE incidence was 40.9% (122/298) and 0.3% (1/298), respectively. No grade 4 or 5 RE was observed. All RE cases resolved within 1 month after RT, and the median duration of RE was 3 weeks (range, 1-5). Based on univariable analyses, tumor laterality (p < .001), IMNI (p = .056) and esophageal Dmean, Dmax, RV10-RV40, and AV10-AV40 were risk factors of ≥grade 2 RE. Esophageal RV10-RV40 and AV35-AV40 were significantly associated with the risk of ≥grade 2 RE after adjusting for tumor laterality and IMNI. Based on multivariable analyses, RV25 and AV35 were optimum dose-volume predictors for ≥grade 2 RE at thresholds 20% for RV25 (35.9% vs. 60.9%, p = .04) and 0.27 mL for AV35 (31.0% vs. 54.6%, p = .04).

CONCLUSION

RE is common in breast cancer patients undergoing hypofractionated RNI. With the same esophageal contouring standard, maintaining the upper esophageal V25 at <20% and V35 at <0.27 mL may decrease the risk of RE and improve the quality of life of patients.

Quality Assurance in a Phase III, Multicenter, Randomized Trial of POstmastectomy radioThErapy in Node posiTive Breast Cancer with or without Internal mAmmary nodaL Irradiation (POTENTIAL): A Planning Dummy Run

PURPOSE/OBJECTIVE(S)

To report the planning dummy run results of the POstmastectomy radioThErapy in Node posiTive breast cancer with or without Internal mAmmary nodaL irradiation (POTENTIAL) trial-a multicenter, randomized, phase 3 trial-to evaluate postmastectomy radiotherapy, with or without internal mammary nodal irradiation, for patients with high-risk breast cancer.

MATERIALS/METHODS

All participating institutions were provided the contours of the dummy run case, and they generated radiotherapy (RT) plans per protocol guidelines. The plans were reviewed and feedback were provided by the quality assurance team, after which the institutions resubmitted revised plans. The information on beams arrangement, skin flash, inhomogeneity corrections, and protocol compliance was assessed both in the primary and final submission.

RESULTS

Theplans from 26 institutions were included in the analysis. A number of major deviations were found in the primary submission, such as less strict constraint on organs at risk (OARs) V5Gy, and no application of chest wall skin flash. The protocol compliance rates of the dose coverage for the planning target volume of the chest wall (PTVcw), PTV of supra/infraclavicular fossa plus axilla levels I, II, III (PTVsc+ax), and PTV of the IMN region (PTVim) were all significantly improved in the final submission compared with those in the primary submission, which were 96.2% vs. 69.2%, 100% vs. 76.9%, and 88.4% vs. 53.8, respectively. For OARs, the protocol compliance rates of heart Dmean, left anterior descending coronary artery V40Gy, ipsilateral lung V5Gy, and stomach V5Gy were significantly improved.

CONCLUSION

All major deviations were corrected and protocol compliance was significantly improved and of high level in the final submission. Moreover, the variations were reduced. Therefore, a planning dummy run was essential to guarantee good RT plan quality and inter-institutional consistency for multicenter trials.

Ten-Year Outcomes of Hypofractionated (45 Gy in 9 Fractions) Intensity Modulated Radiotherapy for Localized Prostate Cancer

PURPOSE/OBJECTIVE(S)

We reported 10-year outcomes of localized prostate cancers treated with hypofractionated intensity-modulated radiotherapy of 45 Gy in 9 consecutive fractions.

MATERIALS/METHODS

From October 2011 to April 2017, thirty patients with localized prostate cancer were enrolled in this prospective trial. The median age of the patients was 72.5 years. According to NCCN recurrence risk criteria, eight patients were at low-risk group, 17 at intermediate risk group, 5 at high-risk group. All patients were treated with hypofractionated intensity-modulated radiotherapy (IMRT) of 45 Gy in 9 consecutive fractions to their prostate with or without seminal vesicles. Before radiotherapy, three gold fiducials were implanted into the prostate. In order to reduce the rectal high dose irradiation volume, an inflated rectal balloon was placed in the rectum at simulation and every treatment and patients were treated with comfortable full bladder. Static Intensity-modulated radiotherapy (SIMRT) was applied in 1 patient, Volumetric Modulated Arc Therapy (VMAT) in 27 patients, and tomotherapy in 2 patients. Image guided radiotherapy (IGRT) with gold fiducial registration was adopted. Twenty-six patients also received androgen deprivation therapy (ADT). The median time of ADT was 6 months. Progression⁃free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier analysis. All grade ≥1 genitourinary (GU) and gastrointestinal (GI) toxicities were recorded using Common Terminology Criteria for Adverse Event version 5.0 (CTCAE 5.0) and Radiation Therapy Oncology Group (RTOG) late morbidity criteria, and GU and GI toxicities were cumulatively calculated.

RESULTS

After a median follow-up of 102 months (65∼131 months), the 10-year OS was 90.0% (95% confidence interval, 83.3%-96.7%), and the 10-year PFS was 86.5% (95% confidence interval, 79.1%-93.9%). According to CTCAE 5.0, grade 1 acute gastrointestinal (GI) toxicity developed in 12 patients, grade 2 in 2 patients, grade 3 in 2 patients, and grade 1 acute genitourinary (GU) toxicity developed in 12 patients, grade 2 in 2 patients, and no grade 3 or higher toxicity occurred. According to RTOG late morbidity criteria, late (≥3 months after radiotherapy) grade 1 GI toxicity developed in 4 patients (13.3%), grade 2 in 1 (3.3%), grade 3 in 1 (3.3%), and late grade 1 GU toxicity occurred in 1 patient (3.3%), grade 2 in 1 (3.3%), grade 3 in 1 (3.3%). No grade 4 or higher GI and GU toxicities developed. Only one grade 3 GI and one grade 2 GU toxicities were observed for the maximum toxicity at the last follow-up. The potency was not evaluated.

CONCLUSION

The 10-year oncologic outcomes of this shortened hypofractionated IMRT regimen for mainly low/intermediate risk prostate cancer patients is favorable with acceptable acute and late toxicities.

[International comparison and assessment of the quality of drug clinical trial implementation in China based on scientific regulatory system]

With the rapid development of clinical research and the continuous enhancement of innovation capability in China, the quality of clinical research under China's scientific regulatory system has drawn widespread attention. This study evaluated the quality results of China's drug clinical trials implementation, compared the scientific regulatory systems of clinical research quality between China and the United States, analyzed real-world clinical application on the approval of new anti-tumor drugs through clinical trials, in order to analyze China's status and level of clinical trial implementation quality in the international industry, and explore the advantages and value of China's clinical research scientific regulation by collecting clinical trial data inspections disclosed by regulatory agencies in both China and the United States, as well as verifying information on the approval of new anti-tumor drugs.

[Application and research progress of permissive hypocaloric nutrition in nutritional therapy of severe burns]

Nutritional therapy plays an important role in the treatment of severe burns. With the deepening understanding of metabolic patterns and body responses after severe burns, the concepts and measures of nutritional therapy are also constantly developing and improving. Permissive hypocaloric nutrition is a nutritional management approach for critically ill patients, which generally refers to a nutritional administration method in which energy intake is lower than 70% of caloric requirement. This article aims to review the metabolic characteristics after severe burns, as well as the implementation timing, duration, target calories, and nutritional content of permissive hypocaloric nutrition, in order to provide reference for clinical decision-making by clinical physicians, improve the efficacy of nutritional treatment for severe burn patients, and improve patients' prognosis.

[Study on the recurrence pattern of rectal cancer patients undergoing radical surgery after neoadjuvant chemoradiotherapy]

Objective: To analyze the recurrence pattern of rectal cancer patients with radical surgery after neoadjuvant chemoradiotherapy. Methods: The clinicopathological characteristics and follow-up information of rectal cancer patients with radical surgery after neoadjuvant chemoradiotherapy in the Cancer Hospital of the Chinese Academy of Medical Sciences from June 2004 to December 2017 were retrospectively collected. The recurrence pattern including the time and site was investigated. Results: The age of 537 patients was (55.5±11.7) years, of whom 361 were male (67.2%). The median follow-up time [M(Q₁,Q₃)] was 77.9 (64.5, 95.6) months. Moreover, 30.7% (165/537) of patients had distant metastasis or local recurrence; 26.8% (144/537) of patients had distant metastasis; 5.6% (30/537) of patients had local recurrence; 1.7% (9/537) of patients had both distant metastasis and local recurrence. In all the recurrent patients, 23.6% (39/165) were in the first year after surgery, followed by 27.3% (45/165) in the second year, 17.0% (28/165) in the third year, and 15.8% (26/165) after five years. According to the risk curve drawn by the life table, the highest metastasis risk of patients occurred in the second year after surgery, and the metastasis risk peak occurred again after more than five years. The lung was the most common metastatic organ, accounting for 47.9% (69/144), followed by the liver (18.8%, 27/144). The ratios of the recurrent patients in each ypTNM stage were 9.5% (8/84), 12.0% (12/100), 26.5% (41/155), 52.5% (104/198), respectively. The proportion of recurrent patients in tumor regression grade (TRG) 1-2 and TRG 3-5 patients were 19.2% (38/198) and 37.5% (127/339), respectively. Conclusions: The recurrence pattern of patients undergoing radical surgery after neoadjuvant chemoradiotherapy is mainly distant metastasis. The lung is the primary metastatic organ. The risk of distant metastasis and local recurrence is high in the first three years after surgery, and there is still high risk of recurrence after five years. For patients with ypTNM stage 2, 3 and TRG3-5, the postoperative adjuvant chemotherapy and long-term follow-up should be strengthened.

[A long-term follow-up study on recurrence and benefit of standardized postoperative chemotherapy of rectal cancer patients with complete pathological response after neoadjuvant chemoradiotherapy]

Objective: To analyze the clinicopathological factors affecting long-term disease-free survival and the characteristics of local recurrence or distance metastasis of rectal cancer patients with complete pathological response after neoadjuvant chemoradiotherapy. Methods: The clinicopathological data and follow-up information of patients with a complete pathological response of rectal cancer after neoadjuvant chemoradiotherapy in the Cancer Hospital of Chinese Academy of Medical Sciences from June 2004 to December 2019 were retrospectively collected. The clinicopathological factors affecting the long-term disease-free survival of patients were analyzed to build a prediction model of local recurrence and distant metastasis and to evaluate the benefits of postoperative chemotherapy. Results: The age of 108 patients was(56.3±11.6) years, of which 68 were males (63.0%); The median follow-up time was 79.9 (61.8, 112.6) months. There were 12 patients (11.1%) who had a local recurrence or distant metastasis. The 5-year disease-free survival rate was 91.1% with 9 patients who experienced recurrence. Multivariate Cox proportional hazards regression analysis showed that the maximum diameter of the residual tumor or scar (HR=8.41, 95%CI: 1.08-65.22, P=0.042) and the distance from the lower edge of the tumor to the anal margin before treatment (HR=4.54, 95%CI: 1.23-16.81, P=0.023) were independent risk factors affecting the prognosis. The prognosis of patients was stratified based on relevant factors. The 5-year cumulative disease-free survival rate of those patients receiving postoperative standardized chemotherapy was 92.0%, while for patients who did not receive or complete standardized chemotherapy, the 5-year cumulative disease-free survival rate was 82.3%. Conclusions: The maximum diameter of the residual tumor or scar and the distance from the lower edge of the tumor to the anal margin before treatment were independent risk factors affecting the prognosis of patients with a complete pathological response. Patients with independent risk factors could benefit from the standardized postoperative chemotherapy.

Small extracellular vesicles promote invadopodia activity in glioblastoma cells in a therapy-dependent manner

PURPOSE

The therapeutic efficacy of radiotherapy/temozolomide treatment for glioblastoma (GBM) is limited by the augmented invasiveness mediated by invadopodia activity of surviving GBM cells. As yet, however the underlying mechanisms remain poorly understood. Due to their ability to transport oncogenic material between cells, small extracellular vesicles (sEVs) have emerged as key mediators of tumour progression. We hypothesize that the sustained growth and invasion of cancer cells depends on bidirectional sEV-mediated cell-cell communication.

METHODS

Invadopodia assays and zymography gels were used to examine the invadopodia activity capacity of GBM cells. Differential ultracentrifugation was utilized to isolate sEVs from conditioned medium and proteomic analyses were conducted on both GBM cell lines and their sEVs to determine the cargo present within the sEVs. In addition, the impact of radiotherapy and temozolomide treatment of GBM cells was studied.

RESULTS

We found that GBM cells form active invadopodia and secrete sEVs containing the matrix metalloproteinase MMP-2. Subsequent proteomic studies revealed the presence of an invadopodia-related protein sEV cargo and that sEVs from highly invadopodia active GBM cells (LN229) increase invadopodia activity in sEV recipient GBM cells. We also found that GBM cells displayed increases in invadopodia activity and sEV secretion post radiation/temozolomide treatment. Together, these data reveal a relationship between invadopodia and sEV composition/secretion/uptake in promoting the invasiveness of GBM cells.

CONCLUSIONS

Our data indicate that sEVs secreted by GBM cells can facilitate tumour invasion by promoting invadopodia activity in recipient cells, which may be enhanced by treatment with radio-chemotherapy. The transfer of pro-invasive cargos may yield important insights into the functional capacity of sEVs in invadopodia.

Abstract 2366: Myeloma-derived circulating extracellular vesicles affect human stromal cell behaviour and promote tumor progression: A multi-omic approach

Background: We have shown that human stromal cells (HS5) treated with small extracellular vesicles (EV) derived from plasma of myeloma (MM) patients (MM-EV) promoted adhesion of human MM cell lines (HMCL), with preliminary proteomic profiling of MM- vs healthy donors HD-EV revealing enrichment of factors implicated in cell migration and adhesion.

Aims: 1) Demonstrate that MM-EV induce the formation of a tumour microenvironment (TME) favouring MM progression; 2) identify the protein content of MM-EV promoting this; 3) discover signaling drivers of EV-mediated functional remodelling of HS5 towards a pre-metastatic phenotype.

Methods: EV were enriched from 1mL plasma using a commercial kit. We performed: proteomic profiling of EV [x10 HD, x8 MM, x4 asymptomatic MM, x10 premalignant stage MGUS]; phosphoproteomic profiling and gene expression analysis by RNA sequencing of HS5 cells pre-treated with MM- vs HD/MGUS-EV; functional studies (co-culture HS5:HMCL).

Results: HS5 cells treated with MM-EV induced HMCL proliferation (p =.0026) and drug resistance (p =.0013) to anti-MM drugs (proteasome inhibitors) when compared to untreated HS5-cells.412 proteins were quantified by proteomic profiling of EV with 8/13 corresponding to universal cancer EV markers (Hoshino et al, Cell 2020). Gene ontology analysis of identified proteins (G:Profiler; p &lt;.05) revealed enrichment for cellular component terms such as “extracellular vesicles/exosomes” and for biological processes including “cell communication”, “endocytosis”. Comparative analysis between our dataset and publicly available datasets revealed EV-markers with potential discriminatory specificity for MM. Comparative analysis revealed 40 proteins differentially regulated between HD- and MM-EV (p &lt;.05; log2 fold change ≥2). A specific protein signature was found in ≥30% of MM-EV vs ≤30% HD-EV. A specific protein signature was also identified in ≥30% of MGUS-EV vs ≤30% HD/MM/SMM-EV. These proteins were not found in human whole plasma (Lehallier et al, Nat Med 2019) or solid tumors-EV (Hoshino et al, Cell 2020; Vinik et al, Science Advances 2020).120 phosphosites were differentially expressed between HS5 pre-treated with MM-EV vs HD-EV (&gt;1.5-fold change, p&lt;.05). Among the differentially expressed proteins were kinases,

phosphatases, translation and transcription regulators. 624 gene terms were differentially expressed between HS5 pre-treated with MM- vs HD-EV (GSEA, FDR &lt; 0.05), including epidermal growth factor (EGF), tumor necrosis factor alpha (TNFA), epithelial to mesenchymal transition (EMT) signaling.

Conclusion: In this first of its kind studies in MM we show that MM-EV may play a key role in disease progression by re-programming the TME. Ongoing studies will indicate: the value of MM-EV as biomarkers; whether targeting interactions MM-EV:HS5 could enforce current therapeutic strategies.

Citation Format: Antonia Reale, Rong Xu, Irena Carmichael, Haoyun Fang, Jaynish S Sha, Tiffany Khong, Nicholas Bingham, Malarmathy Ramachandran, Maoshan Chen, David W Greening, Andrew Spencer. Myeloma-derived circulating extracellular vesicles affect human stromal cell behaviour and promote tumor progression: A multi-omic approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2366.