Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector

This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139  fb^{-1} of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688±23(stat) _{-71}^{+75}(syst)  fb, to be compared with the standard model prediction of 515_{-42}^{+36}  fb at next-to-leading order in QCD.

Observation of New Baryons in the Ξ_{b}^{-}π^{+}π^{-} and Ξ_{b}^{0}π^{+}π^{-} Systems

The first observation and study of two new baryonic structures in the final state Ξ_{b}^{0}π^{+}π^{-} and the confirmation of the Ξ_{b}(6100)^{-} state in the Ξ_{b}^{-}π^{+}π^{-} decay mode are reported using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1}. In addition, the properties of the known Ξ_{b}^{*0}, Ξ_{b}^{'-} and Ξ_{b}^{*-} resonances are measured with improved precision. The new decay mode of the Ξ_{b}^{0} baryon to the Ξ_{c}^{+} π^{-} π^{+} π^{-} final state is observed and exploited for the first time in these measurements.

Measurement of Suppression of Large-Radius Jets and Its Dependence on Substructure in Pb+Pb Collisions at sqrt[s_{NN}]=5.02 TeV with the ATLAS Detector

This letter presents a measurement of the nuclear modification factor of large-radius jets in sqrt[s_{NN}]=5.02  TeV Pb+Pb collisions by the ATLAS experiment. The measurement is performed using 1.72  nb^{-1} and 257  pb^{-1} of Pb+Pb and pp data, respectively. The large-radius jets are reconstructed with the anti-k_{t} algorithm using a radius parameter of R=1.0, by reclustering anti-k_{t} R=0.2 jets, and are measured over the transverse momentum (p_{T}) kinematic range of 158 Collapse

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Precision Measurement of CP Violation in the Penguin-Mediated Decay B_{s}^{0}→ϕϕ

A flavor-tagged time-dependent angular analysis of the decay B_{s}^{0}→ϕϕ is performed using pp collision data collected by the LHCb experiment at the center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6  fb^{-1}. The CP-violating phase and direct CP-violation parameter are measured to be ϕ_{s}^{ss[over ¯]s}=-0.042±0.075±0.009  rad and |λ|=1.004±0.030±0.009, respectively, assuming the same values for all polarization states of the ϕϕ system. In these results, the first uncertainties are statistical and the second systematic. These parameters are also determined separately for each polarization state, showing no evidence for polarization dependence. The results are combined with previous LHCb measurements using pp collisions at center-of-mass energies of 7 and 8 TeV, yielding ϕ_{s}^{ss[over ¯]s}=-0.074±0.069  rad and |λ|=1.009±0.030. This is the most precise study of time-dependent CP violation in a penguin-dominated B meson decay. The results are consistent with CP symmetry and with the standard model predictions.

[Safety of double and a half layered esophagojejunal anastomosis in radical gastrectomy: A prospective, multi-center, single arm trial]

Objective: To evaluate the safety of double and a half layered esophagojejunal anastomosis in radical gastrectomy. Methods: This prospective, multi-center, single-arm study was initiated by the Affiliated Cancer Hospital of Zhengzhou University in June 2021 (CRAFT Study, NCT05282563). Participating institutions included Nanyang Central Hospital, Zhumadian Central Hospital, Luoyang Central Hospital, First Affiliated Hospital of Henan Polytechnic University, First Affiliated Hospital of Henan University, Luohe Central Hospital, the People's Hospital of Hebi, First People's Hospital of Shangqiu, Anyang Tumor Hospital, First People's Hospital of Pingdingshan, and Zhengzhou Central Hospital Affiliated to Zhengzhou University. Inclusion criteria were as follows: (1) gastric adenocarcinoma confirmed by preoperative gastroscopy;(2) preoperative imaging assessment indicated that R0 resection was feasible; (3) preoperative assessment showed no contraindications to surgery;(4) esophagojejunostomy planned during the procedure; (5) patients volunteered to participate in this study and gave their written informed consent; (6) ECOG score 0-1; and (7) ASA score I-III. Exclusion criteria were as follows: (1) history of upper abdominal surgery (except laparoscopic cholecystectomy);(2) history of gastric surgery (except endoscopic submucosal dissection and endoscopic mucosal resection); (3) pregnancy or lactation;(4) emergency surgery for gastric cancer-related complications (perforation, hemorrhage, obstruction); (5) other malignant tumors within 5 years or coexisting malignant tumors;(6) arterial embolism within 6 months, such as angina pectoris, myocardial infarction, and cerebrovascular accident; and (7) comorbidities or mental health abnormalities that could affect patients' participation in the study. Patients were eliminated from the study if: (1) radical gastrectomy could not be completed; (2) end-to-side esophagojejunal anastomosis was not performed during the procedure; or (3) esophagojejunal anastomosis reinforcement was not possible. Double and a half layered esophagojejunal anastomosis was performed as follows: (1) Open surgery: the full thickness of the anastomosis is continuously sutured, followed by embedding the seromuscular layer with barbed or 3-0 absorbable sutures. The anastomosis is sutured with an average of six to eight stitches. (2) Laparoscopic surgery: the anastomosis is strengthened by counterclockwise full-layer sutures. Once the anastomosis has been sutured to the right posterior aspect of the anastomosis, the jejunum stump is pulled to the right and the anastomosis turned over to continue to complete reinforcement of the posterior wall. The suture interval is approximately 5 mm. After completing the full-thickness suture, the anastomosis is embedded in the seromuscular layer. Relevant data of patients who had undergone radical gastrectomy in the above 12 centers from June 2021 were collected and analyzed. The primary outcome was safety (e.g., postoperative complications, and treatment). Other studied variables included details of surgery (e.g., surgery time, intraoperative bleeding), postoperative recovery (postoperative time to passing flatus and oral intake, length of hospital stay), and follow-up conditions (quality of life as assessed by Visick scores). Result: [1] From June 2021 to September 2022,457 patients were enrolled, including 355 men and 102 women of median age 60.8±10.1 years and BMI 23.7±3.2 kg/m2. The tumors were located in the upper stomach in 294 patients, mid stomach in 139; and lower stomach in 24. The surgical procedures comprised 48 proximal gastrectomies and 409 total gastrectomies. Neoadjuvant chemotherapy was administered to 85 patients. Other organs were resected in 85 patients. The maximum tumor diameter was 4.3±2.2 cm, number of excised lymph nodes 28.3±15.2, and number of positive lymph nodes five (range one to four. As to pathological stage,83 patients had Stage I disease, 128 Stage II, 237 Stage III, and nine Stage IV. [2] The studied surgery-related variables were as follows: The operation was successfully completed in all patients, 352 via a transabdominal approach, 25 via a transhiatus approach, and 80 via a transthoracoabdominal approach. The whole procedure was performed laparoscopically in 53 patients (11.6%), 189 (41.4%) underwent laparoscopic-assisted surgery, and 215 (47.0%) underwent open surgery. The median intraoperative blood loss was 200 (range, 10-1 350) mL, and the operating time 215.6±66.7 minutes. The anastomotic reinforcement time was 2 (7.3±3.9) minutes for laparoscopic-assisted surgery, 17.6±1.7 minutes for total laparoscopy, and 6.0±1.2 minutes for open surgery. [3] The studied postoperative variables were as follows: The median time to postoperative passage of flatus was 3.1±1.1 days and the postoperative gastrointestinal angiography time 6 (range, 4-13) days. The median time to postoperative oral intake was 7 (range, 2-14) days, and the postoperative hospitalization time 15.8±6.7 days. [4] The safety-related variables were as follows: In total, there were 184 (40.3%) postoperative complications. These comprised esophagojejunal anastomosis complications in 10 patients (2.2%), four (0.9%) being anastomotic leakage (including two cases of subclinical leakage and two of clinical leakage; all resolved with conservative treatment); and six patients (1.3%) with anastomotic stenosis (two who underwent endoscopic balloon dilation 21 and 46 days after surgery, the others improved after a change in diet). There was no anastomotic bleeding. Non-anastomotic complications occurred in 174 patients (38.1%). All patients attended for follow-up at least once, the median follow-up time being 10 (3-18) months. Visick grades were as follows: Class I, 89.1% (407/457); Class II, 7.9% (36/457); Class III, 2.6% (12/457); and Class IV 0.4% (2/457). Conclusion: Double and a half layered esophagojejunal anastomosis in radical gastrectomy is safe and feasible.

Measurement of the Sensitivity of Two-Particle Correlations in pp Collisions to the Presence of Hard Scatterings

A key open question in the study of multiparticle production in high-energy pp collisions is the relationship between the "ridge"-i.e., the observed azimuthal correlations between particles in the underlying event that extend over all rapidities-and hard or semihard scattering processes. In particular, it is not known whether jets or their soft fragments are correlated with particles in the underlying event. To address this question, two-particle correlations are measured in pp collisions at sqrt[s]=13  TeV using data collected by the ATLAS experiment at the LHC, with an integrated luminosity of 15.8  pb^{-1}, in two different configurations. In the first case, charged particles associated with jets are excluded from the correlation analysis, while in the second case, correlations are measured between particles within jets and charged particles from the underlying event. Second-order flow coefficients, v_{2}, are presented as a function of event multiplicity and transverse momentum. These measurements show that excluding particles associated with jets does not affect the measured correlations. Moreover, particles associated with jets do not exhibit any significant azimuthal correlations with the underlying event, ruling out hard processes contributing to the ridge.

The spatial and temporal dynamics of sediment phosphorus attenuation and release in impacted stream catchments

Sediments can attenuate phosphorus (P) from overlying water and reduce trophic status in zero and first order ditches and streams. These features can be considered as intermediate mitigation features between P mobilised from land, and onward delivery to river systems, if the risk of chemical P release from sediments is minimal. However, risk assessments are rarely based on temporal scale dynamics and especially at fine scale in both sediment and water column environments. In this study, in eutrophic stream catchments, bed sediments were tested fortnightly and spatially over one year for EPC0 (to derive phosphate exchange potential-PEP) and for P across a spectrum from labile to recalcitrant fractions. At the same time stream discharge and P concentrations were measured synchronously at high frequency and resolved to 1-hour intervals and indicated high water quality pressures at all flow rates. PEP indicated spatial and temporal changes most likely caused by periods of source disconnection/reconnection and sediment mobilisation during storm events, moving from periods of high attenuation potential to near saturation. Despite these spatial and temporal changes, PEP did not indicate much potential for chemical P release from the sediments (distributing mostly below or close to zero). However, this may be a misleading risk assessment by itself as physical P release, especially of the labile bicarbonate-dithionite (B-D) P fraction of sediments, was a more dominant process mobilised during storm events reducing by up to 84 % during a succession of summer storm events. The total P and total reactive P loads monitored leaving the catchments were coincident with these changes. The specific downstream trophic effects of this episodic P release will need to be assessed in terms of its bioavailability, in combination with other more noted diffuse and point P source processes.

Measurement of the Λ_{b}^{0}→Λ(1520)μ^{+}μ^{-} Differential Branching Fraction

The branching fraction of the rare decay Λ_{b}^{0}→Λ(1520)μ^{+}μ^{-} is measured for the first time, in the squared dimuon mass intervals q^{2}, excluding the J/ψ and ψ(2S) regions. The data sample analyzed was collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9  fb^{-1}. The result in the highest q^{2} interval, q^{2}>15.0  GeV^{2}/c^{4}, where theoretical predictions have the smallest model dependence, agrees with the predictions.

Temporal Structures in Positron Spectra and Charge-Sign Effects in Galactic Cosmic Rays

We present the precision measurements of 11 years of daily cosmic positron fluxes in the rigidity range from 1.00 to 41.9 GV based on 3.4×10^{6} positrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The positron fluxes show distinctly different time variations from the electron fluxes at short and long timescales. A hysteresis between the electron fluxes and the positron fluxes is observed with a significance greater than 5σ at rigidities below 8.5 GV. On the contrary, the positron fluxes and the proton fluxes show similar time variation. Remarkably, we found that positron fluxes are modulated more than proton fluxes with a significance greater than 5σ for rigidities below 7 GV. These continuous daily positron fluxes, together with AMS daily electron, proton, and helium fluxes over an 11-year solar cycle, provide unique input to the understanding of both the charge-sign and mass dependencies of cosmic rays in the heliosphere.

Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector

A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[s]=13  TeV, corresponding to an integrated luminosity of 140  fb^{-1} recorded by the ATLAS experiment at LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds are estimated based on a hybrid approach involving Monte Carlo simulations and data-driven methods. Statistically significant excesses with respect to backgrounds dominated by the single parton scattering are seen in the di-J/ψ channel consistent with a narrow resonance at 6.9 GeV and a broader structure at lower mass. A statistically significant excess is also seen in the J/ψ+ψ(2S) channel. The fitted masses and decay widths of the structures are reported.

Observation of the γγ→ττ Process in Pb+Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS Detector

This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment a_{τ}. The dataset corresponds to an integrated luminosity of 1.44  nb^{-1} of LHC Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a τ-lepton decay, an electron or charged-particle track(s) from the other τ-lepton decay, little additional central-detector activity, and no forward neutrons. The γγ→ττ process is observed in Pb+Pb collisions with a significance exceeding 5 standard deviations and a signal strength of μ_{ττ}=1.03_{-0.05}^{+0.06} assuming the standard model value for a_{τ}. To measure a_{τ}, a template fit to the muon transverse-momentum distribution from τ-lepton candidates is performed, using a dimuon (γγ→μμ) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a_{τ} is -0.057 Collapse

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[Impact of COVID-19 pandemic on the management of imported malaria in China]

OBJECTIVE

To examine the impact of COVID-19 pandemic on the epidemic status of imported malaria and national malaria control program in China, so as to provide insights into post-elimination malaria surveillance.

METHODS

All data pertaining to imported malaria cases were collected from Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 through December 31, 2021. The number of malaria cases, species of malaria parasites, country where malaria parasite were infected, diagnosis and treatment after returning to China, and response were compared before (from January 1, 2018 to January 22, 2020) and after the COVID-19 pandemic (from January 23, 2020 to December 31, 2021).

RESULTS

A total of 2 054 imported malaria cases were reported in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 to December 31, 2021, and there were 1 722 cases and 332 cases reported before and after the COVID-19 pandemic, respectively. All cases were reported within one day after definitive diagnosis. The annual mean number of reported malaria cases reduced by 79.30% in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region after the COVID-19 pandemic (171 cases) than before the pandemic (826 cases), and the number of monthly reported malaria cases significantly reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region since February 2020. There was a significant difference in the constituent ratio of species of malaria parasites among the imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ2 = 146.70, P < 0.05), and P. falciparum malaria was predominant before the COVID-19 pandemic (72.30%), while P. ovale malaria (44.28%) was predominant after the COVID-19 pandemic, followed by P. falciparum malaria (37.65%). There was a significant difference in the constituent ratio of country where malaria parasites were infected among imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ2 = 13.83, P < 0.05), and the proportion of malaria cases that acquired Plasmodium infections in western Africa reduced after the COVID-19 pandemic that before the pandemic (44.13% vs. 37.95%; χ2 = 4.34, P < 0.05), while the proportion of malaria cases that acquired Plasmodium infections in eastern Africa increased after the COVID-19 pandemic that before the pandemic (9.58% vs. 15.36%; χ2 = 9.88, P = 0.02). The proportion of completing case investigation within 3 days was significantly lower after the COVID-19 pandemic than before the pandemic (96.69% vs. 98.32%; χ2= 3.87, P < 0.05), while the proportion of finishing foci investigation and response within 7 days was significantly higher after the COVID-19 pandemic than before the pandemic (100.00% vs. 98.43%; χ2 = 3.95, P < 0.05).

CONCLUSIONS

The number of imported malaria cases remarkably reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region of China during the COVID-19 pandemic, with a decreased proportion of completing case investigations within 3 days. The sensitivity of the malaria surveillance-response system requires to be improved to prevent the risk of secondary transmission of malaria due to the sharp increase in the number of imported malaria cases following the change of the COVID-19 containment policy.

[Establishment of a rapid method for detection of influenza A/B virus' antigens]

This study aims to develop a rapid and convenient test card for simultaneous detection of influenza A and influenza B viruses using quantum dot-based immunochromatographic assay. The test card consists of a test strip and a plastic casing. The test strip is composed of absorbent paper, a buffer pad, nitrocellulose membrane (NC membrane), sample pad, quantum dot-labeled antibody pad, and polyvinyl chloride (PVC) board. The NC membrane is coated with mouse monoclonal antibodies against influenza A and influenza B viruses for the T lines (test lines), and reference proteins A and B for the C line (control line). The quantum dot-labeled antibody pad contains mouse monoclonal antibody-quantum dot conjugates against influenza A and influenza B viruses. The results showed that the detection limit of the test card for both viruses ranged from 1.51 ×102 to 2.71×103 TCID50/ml, indicating its sensitivity for accurate detection of influenza A and influenza B viruses without being affected by various variants. The test card exhibited specific reactions with different subtypes of influenza A and influenza B virus culture fluids and showed no cross-reactivity with adenovirus, novel coronavirus, Mycoplasma pneumoniae, respiratory syncytial virus, Staphylococcus aureus, and other pathogens. Overall, the sensitivity and specificity of the test card for simultaneous detection of influenza A and influenza B viruses meet the requirements for clinical use. It offers the advantages of simplicity, rapidity, and no requirement for special equipment, enabling quick auxiliary diagnosis to prevent disease transmission.

The Potential Ability of Plan Complexity Metrics on the Dose Calculation and Plans Delivery in Intensity Modulated Radiotherapy

PURPOSE/OBJECTIVE(S)

The excessive modulation of treatment plan during radiotherapy (RT) increases the complexity. Evaluation of the multidimensional relationship between program complexity metrics, computation-based patient-specific quality assurance (PSQA), and conventional measurement-based PSQA could assist in enhancing the robustness of treatment planning, guide the allocation of clinical QA resources, and ultimately lessen QA workload.

MATERIALS/METHODS

The fifty-five metrics affecting RT planning and delivery accuracy were calculated by a house-built program to describe the complexity of 404 dynamic IMRT plans, with sensitivity to the small field, aperture position, MLC edge, low MUs, MLC leaf motion, leaf speed/acceleration, etc. The calculation-based PSQA was performed using Monte Carlo (MC) method and Collapsed Cone Convolution (CCC) algorithm, implemented in SciMoCa and Mobius 3D, respectively. The measurement-based PSQA was performed using 3D diode arrays with different geometries covering "O", "+" and " × " shapes which exist in ArcCheck, Delta4 phantom+ (Delta4) and Delta4PT phantom (Delta4PT), respectively. Gamma passing rates (GPRs) were recorded to measure the results of each QA system. This multidimensional relationship was evaluated using correlation analysis and principal component linear regression (PCR) analysis.

RESULTS

A total of 4448 GPRs for various QA systems corresponding to two Linacs were counted. The modulation index for speed (MIs) and modulation index for acceleration (MIa) were consistently located at the high points of the radarplots of the Spearman correlation coefficient |rs| between metrics and GPRs of the four QA systems, just except Delta4. Besides, the rs between SciMoCa and ArcCheck were 0.275-0.531 (P ≤ 0.001), SciMoCa and Delta4 were 0.32-0.418 (P ≤ 0.001), and Mobius 3Dand Delta4PT were 0.124-0.226 (P ≤ 0.05). The PCR model's coefficients determination (R2) for SciMoCa were 0.461-0.756 (P ≤ 0.001), ArcCheck were 0.243-0.440 (P ≤ 0.001), Delta4 were 0.268-0.402 (P ≤ 0.001), Mobius 3D were 0.299-0.407 (P ≤ 0.001), and Delta4PT were 0.087-0.141 (P ≤ 0.05).

CONCLUSION

This study is the first overall assessment of the impact of various complexity metrics on the accuracy of TPS calculation and Linac delivery. Of the metrics studied, MIs and MIa metrics have a standout impact on the ability of the TPS calculation and delivery system, extra attention should be paid during the planning process. It is inappropriate to utilize calculation-based QA to predict the results of measurement-based QA since there is a poor correlation between the two. Furthermore, calculation-based QA outperforms measurement-based QA in identifying highly complex plans, which can further guide clinical QA process optimization and save limited clinical resources.

Identification and Validation of a Ferroptosis Prognostic Model for Prostate Cancer Patients through Screening the TCGA and scRNA-seq Datasets

PURPOSE/OBJECTIVE(S)

Ferroptosis is currently a common mode of programmed cell death, and the induction of ferroptosis is a new strategy and idea for current tumor therapy. Therefore, the signaling pathways and genes regulated by ferroptosis are significant markers for current malignant tumor therapy. To construct a prognostic model for predicting the survival prognosis of prostate cancer (PCa) based on the molecules and markers related to ferroptosis, we combined with differentially expressed genes (DEGs) in PCa patients, and further analyze the correlation between this risk score and immune cell infiltration. Finally, to validate the expression of risk genes and analyze the expression and localization of risk genes in using the datasets of single cell RNA-sequencing (scRNA-seq).

MATERIALS/METHODS

Firstly, we screened the DEGs in PCa patients by the expression profiles of TCGA database. Meanwhile, we collected the information of ferroptosis regulatory genes from FerrDb, and these two parts were intersected. Then the impact of genes on the survival and prognosis of PCa patients was confirmed and selected by LASSO regression, further screening of molecules and fitting the risk format. And the efficacy of the model was evaluated by ROC curves. The immune cell infiltration of PCa tissues was predicted using TIMER. Last, the scRNA-seq of PCa (GSM5155455, GSM3735993) were carried to reveal the expression of risk molecules in different cell types. Besides, the expression of risk molecules was validated using PCa cell lines.

RESULTS

We found a total of 259 DEGs associated with ferroptosis in PCa tissues. After LASSO regression, we screened DRD5, LINC00336, ACSF2, RRM2, NOX1, GDF15, ALB, MIOX, and NOX4 as variables to establish a prognostic model, and the specific risk scores was calculated following this format: Risk score = (-1.9465)*DRD5+(-1.6806)*LINC00336+(0.3045)*ACSF2+(0.4747)*RRM2+(-0.2815)*NOX1+(-0.1871)* GDF15+(0.1846)*ALB+(0.2676)*MIOX+(0.1648)*NOX4 (lambda.min = 0.0032), with a 10-yr AUC value of 0.751 (95% CI, 0.549-0.953). Furthermore, we discovered the higher the scores, the fewer CD8+ T cells infiltrated as predicting, showing a negative relationship. By testing the gene sets of scRNA-seq forPCa, we discovered that RRM2, GDF15, ALB, and MIOX were mainly expressed in tumor cells, T cells, B cells and neutrophils of PCa tissues, and not in endothelial cells. Finally, we detected differences in protein expression of RRM2, GDF15, and MIOX in PCa cell lines compared to normal prostate cancer epithelium by WB.

CONCLUSION

We constructed a novel prognostic model for PCa based on ferroptosis-related genes, which showed better predictive validity. And we analyzed the cellular expression of risk genes by scRNA-seq, which will be explored future in relation to prostate cancer radiotherapy.

Outcomes and Failure Patterns after Chemoradiotherapy for Locally Advanced Rectal Cancer with Positive Lateral Pelvic Lymph Nodes: A Propensity Score-Matched Analysis

PURPOSE/OBJECTIVE(S)

Locally advanced rectal cancer (LARC) combined with positive lateral pelvic lymph nodes (LPLN) tends to present worse prognosis. However, for those patients it remains unclear whether other combination high-risk factors affect the prognosis. This study aimed to use propensity score matching (PSM) to examine long-term outcomes and failure patterns in patients with positive vs. negative LPLN.

MATERIALS/METHODS

Patients with LARC were retrospectively divided into LPLN-positive and LPLN-negative groups. LPLN-positivity was defined as lymph node short diameter greater than or equal to 7 mm with specific morphological features. Clinical characteristics were compared between the groups using the chi-square test. PSM was applied to balance these differences. Progression-free survival (PFS) and overall survival (OS), and local-regional recurrence (LRR) and distant metastasis (DM) rates were compared between the groups using the Kaplan-Meier method and log-rank tests.

RESULTS

Prior to PSM, a total of 651 LARC patients were included. The LPLN-positive group had higher rates of lower location (53.1% vs. 43.0%, P = 0.025), mesorectal fascia (MRF)-positive (53.9% vs. 35.4%, P<0.001) and extramural venous invasion (EMVI)-positive (51.2% vs. 27.2%, P<0.001) disease than the LPLN-negative group. After PSM, there were 114 patients for each group along with the balanced clinical factors, and both groups had comparable surgery, pathologic complete response (pCR), and ypN stage rates. The median follow-up time was 45.9 months, 3-year OS (88.3% vs. 92.1%, P = 0.276) and LRR (5.7% vs. 2.8%, P = 0.172) rates were comparable between LPLN-positive and LPLN-negative groups. Meanwhile, despite no statistical difference, 3-year PFS (78.8% vs. 85.9%, P = 0.065) and DM (20.4% vs. 13.3%, P = 0.061) rates slightly differed between the groups. Among 10 patients with LRR, seven (70.0%) had lateral pelvic recurrence, among them, five patients were LPLN-positive, and four (80.0%) of these patients did not receive simultaneous integrated boost intensity-modulated radiotherapy (SIB- IMRT).45 patients were diagnosed with DM, 11 (40.7%) LPLN-positive and 3 (17.6%) LPLN-negative patients were diagnosed with oligometastases (P = 0.109).

CONCLUSION

Our study shows there is a tendency of worse PFS and DM in LPLN-positive than LPLN-negative patients, for LPLN-positive patients, oligometastases account for a large proportion of all distant metastases.

Camrelizumab with Chemoradiotherapy for Locally Advanced Biliary Tract Cancer: Preliminary Results from A Phase II Study

PURPOSE/OBJECTIVE(S)

For locally advanced biliary tract cancer (BTC), capecitabine-based chemoradiotherapy (CRT) is commonly used but has limited benefits. Immunotherapy is potentially effective for BTC and may be synergized with CRT. Followed by gemcitabine and cisplatin (GP) consolidation chemotherapy (CT), we evaluated the safety and efficacy of combined camrelizumab and capecitabine-based CRT for locally advanced BTC.

MATERIALS/METHODS

Patients had stage II-III (T4N0M0, T1-4N+M0) BTC (per the 7th [2010] edition of the American Joint Committee on Cancer staging system) were eligible for CRT (capecitabine plus [50-60 Gy] radiotherapy), to be followed by GP CT. Camrelizumab was given concurrently with CRT. Safety was defined as the incidence and severity of adverse events (AEs), while efficacy was defined as overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR).

RESULTS

Ten patients completed the planned treatment. None experienced grade ≥3 treatment-related AEs during CRT. Grade ≥3 immune-related AEs occurred in 2 of 10 patients (20%) only during GP CT. The mean OS time was 18.2 months (95% confidence interval [CI] 12.9m-23.5m) while the median OS time was 14.1 months (95% CI 10.1m-18.1m). OS rates were 100%, 59%, 44% at 6 months, 1 year and 2 years, respectively. The ORR was 30% while the DCR was 90%. Two patients (20%) obtained OS over 2 years with partial response (25.9m, 29.1m). Median PFS time was 14.1 months (95% CI 9.3m-18.9m).

CONCLUSION

Camrelizumab in combination with concurrent CRT was well tolerated and did not impair delivery of CRT in patients with locally advanced BTC.

Sarcopenia as a Predictor of Neoadjuvant Therapy-Related Toxicity in Esophageal Squamous Cell Carcinoma Patients

PURPOSE/OBJECTIVE(S)

Sarcopenia, characterized by loss of muscle mass, plays a critical role in patients with esophageal squamous cell cancer (ESCC). Preoperative chemoradiotherapy and immunotherapy in ESCC patients has been reported to improve survival. Therefore, we sought to evaluate the predictive value of preoperative sarcopenia for toxicity and pathological tumor response to neoadjuvant therapy (NAT) in ESCC patients.

MATERIALS/METHODS

A retrospective analysis was performed using a prospectively collected patient cohort of an academic cancer center diagnosed with cT2-4N0-3M0 ESCC between 2019-2022 and treated with neoadjuvant chemoradiotherapy ± pembrolizumab. Sarcopenia was assessed by skeletal muscle index at the third lumbar vertebra in computed tomography scans before NAT (men: 43cm²/m² for body mass index (BMI) < 25kg/m², 53cm²/m² for BMI≥25 kg/m²; women: 41cm²/m²). Logistic regression was performed to assess the association between sarcopenia and preoperative therapy-related toxicity and tumor response.

RESULTS

The study included 59 locally advanced ESCC patients (53 male and 6 female), 48 (81.4%) in the non-sarcopenia group, and 11 (18.6%) in the sarcopenia group. Mean age at diagnosis was 62±8 years. Mean BMI at diagnosis was 22.13±2.85 kg/m². 19 patients (32.2%) were stage ⅢA, 25 patients (42.4%) were ⅢB, 15 patients (25.4%) were ⅣA. No significant differences were found between both groups regarding sex, age, BMI, and clinical stage. Acute grade ≥3 toxicity occurred significantly more frequently in the sarcopenia group (54.5% vs. 22.9%, p = 0.045), which mainly included leukopenia, neutropenia, anemia and thrombocytopenia. The discontinuation of NAT owing to toxicity occurred in 8 patients (13.5%), which was significantly associated with sarcopenia (p = 0.003). All patients proceeded to surgery and 33 patients (55.9%) had a pathological complete response (pCR). Univariate analysis revealed no significant association between sarcopenia and pCR (p = 0.071).

CONCLUSION

Among patients with locally advanced EC, sarcopenia is not a predictor of poor NAT response, but it is strongly associated with discontinuation of NAT due to toxicity.

Radiotherapy Resistance in Prostate Cancer Cells: AKR1C3 Inhibition of Ubiquitinated Degradation of Nrf2 through Interaction with KEAP1

PURPOSE/OBJECTIVE(S)

Radiotherapy is the most fundamental treatment for prostate cancer (PCa), and although radiotherapy for overall PCa patients is effective, poor prognosis and resistance to multiple treatments regimes in some highly malignant PCa, such as those with high Gleason Scores (GS) (≥9), are important bottlenecks limiting the improvement of treatment outcomes for clinical. AKR1C3 is a key PCa resistance gene that our team identified previously, but the induction of the specific mechanism of radiotherapy resistance has not been fully revealed and understand.

MATERIALS/METHODS

To analyze the correlation between its expression level and clinical radiotherapy, we used the gene expression profiles data of PCa patients in TCGA database. We generated a stepwise increase of radiotherapy dose to established PCa radiotherapy resistant cell lines and detect the AKR1C3 expression level. In addition, to explore the molecular mechanism of AKR1C3 induced prostate cancer radiation tolerance through functional enrichment analysis. Then, to treat cells with cycloheximide and the protein stability of the Nrf2 was detected. Last, the protein ubiquitination level was assayed by co-immunoprecipitation (co-IP) after treatment with MG132. Finally, protein-protein interactions were identified using co-IP to mine possible binding molecules.

RESULTS

By analyzing the expression profiles data of PCa patients in the TCGA database, we found that in the population of PCa patients treated with radiotherapy, all patients with high AKR1C3 expression died after radiotherapy, suggesting that high AKR1C3 expression may be a biomarker of resistance to radiation. Accordingly, AKR1C3 expression levels showed a positive correlation with GS score, which may be a symbol for patients with highly malignant PCa. A PCa radiotherapy resistant cell line was constructed by a stepwise increase of ionizing radiation (IR) dose, and the total IR dose of radiotherapy was 84Gy, which reached the dose of radical radiotherapy for prostate cancer. The expression of AKR1C3 was further detected by RT-qPCR and WB, and it was found that the expression of AKR1C3 was significantly up-regulated in the resistant cell line, accompanied by milder DNA damage. What's more, by GSEA functional enrichment analysis, we discovered that AKR1C3 overexpression might be related with intracellular oxidative stress damage. After CHX treatment, the protein stability of Nrf2 was significantly enhanced in AKR1C3 overexpression groups than control groups. And the administration of MG132 showed the same results, indicating that the ubiquitinated degradation of Nrf2 was inhibited in AKR1C3 overexpression groups. Further by co-IP, we found that Nrf2 was less ubiquitinated in the cytoplasm after AKR1C3 overexpression, and AKR1C3 could bind Keap1.

CONCLUSION

In sum, we found that AKR1C3 can bind with Keap1 leading to reduced ubiquitination level of Nrf2, causing upregulation of Nrf2 expression and providing new insights into PCa radiotherapy resistance.

4D-MRI Guided Stereotactic Body Radiation Therapy for Unresectable Colorectal Liver Metastases

PURPOSE/OBJECTIVE(S)

This study evaluated the feasibilities and outcomes following four-dimensional magnetic resonance imaging (4D-MRI) guided stereotactic body radiation therapy (SBRT) for unresectable colorectal liver metastases (CRLM).

MATERIALS/METHODS

From March 2018 to January 2022, we identified 76 unresectable CRLM patients with 123 lesions who received 4D-MRI guided SBRT in our institution. 4D-MRI simulation with or without abdominal compression was conducted for all patients. The prescription dose was 50-65 Gy in 5-12 fractions. The image quality of computed tomography (CT) and MRI were compared using the Clarity Score. Clinical outcomes and toxicity profiles were evaluated.

RESULTS

The 4D-MRI significantly improved the image quality compared with CT images (mean Clarity Score: 1.67 vs 2.88, P < 0.001). The abdominal compression significantly reduced motions in cranial-caudal direction (P = 0.03) with 2 phase T2 weighted images assessing tumor motion. The median follow-up time was 12.5 months. For 98 lesions assessed for best response, the complete response, partial response and stable disease rate were 57.1 %, 30.6 % and 12.2 %, respectively. The local control (LC) rate at 2 year was 97.3%. 46.1% of patients experienced grade 1-2 toxicities and only 2.6% patients experienced grade 3 hematologic toxicities.

CONCLUSION

The 4D-MRI technique allowed precise target delineation and motion tracking in unresectable CRLM patients. High LC rate and mild toxicities were achieved. This study provided evidence for using 4D-MRI guided SBRT as an alternative treatment in unresectable CRLM.

Complexity Metrics and Planning Dose-Based Pretreatment Patient-Specific Quality Assurance Prediction: Classification, Gamma Passing Rates, and DVH Deviation

PURPOSE/OBJECTIVE(S)

Patient-specific quality assurance (QA) prediction before treatment is beneficial to the clinical resource allocation and the dosimetric monitoring of the patient plans. The aim of this study is to investigate the potential of complexity metrics of radiotherapy plan and patient planning dose to predict QA result, gamma passing rates and dose-volume indices deviation.

MATERIALS/METHODS

Planning dose from treatment planning system (TPS), reconstructed dose from a vendor provided QA phantom and complexity metrics of the 499 radiotherapy plans of patients in our institution from March 2022 to September 2022 were used for methodology verification. Gamma passing rate (3%/2mm,10% threshold) 90% was regarded as criterion of QA pass or fail. A deep learning model ResNet-50 was modified to 3D dose processing and a multilayer perceptron (MLP) with three layers were adopted to extract features from 3D dose and 1D metrics in two parallel ways, then, the features were concatenate together to predict QA results. The dataset was split into 349 for train, 50 for validation and 100 for testing. Evaluation of predictions was based on absolute value deviation and area under the curves (AUC) of receiver operator characteristic (ROC) curve.

RESULTS

In this dataset, 71% (355/499) plans pass the pretreatment QA test. For QA passing prediction in 100 testing cases, the AUC of ROC could achieve 0.92. For gamma passing rates prediction, a mean absolute error (MAE) of 1.8% could be observed for cases with gamma passing rates bigger than 90%, and a MAE of 4.5% deviation could be observed for cases with gamma passing rates from 80% to 90%. For PTV ΔD95 (%) and PTV ΔHI (%), the MAE of prediction and ground truth is 1%. The model with only complexity metrics and only 3D dose could achieve the AUC of ROC 0.91 and 0.84, respectively.

CONCLUSION

The complexity metrics and 3D planning dose-based model could predict pretreatment patient specific QA results with high accuracy and the complexity metrics play a leading role in the model. Dose-volume metrics deviations of PTV could be predicted and more clinically useful information could be provided.

Prediction of Response to Neoadjuvant Chemoradiotherapy Combined with Pembrolizumab in Esophageal Squamous Cell Carcinoma with CT/FDG PET Radiomic Signatures Based on Machine Learning Classification

PURPOSE/OBJECTIVE(S)

PALACE-1 trial has confirm that the addition of pembrolizumab to neoadjuvant chemoradiotherapy (NCRT) improves the pathological complete response(pCR) for esophageal squamous cell carcinoma (ESCC), which might be a novel treatment strategy for ESCC. In the present study, we aim to establish a machine learning model to predict the local response to NCRT+ pembrolizumab for ESCC by using pretreatment 18-fluorodeoxyglucose positron emission tomography (FDG PET) and contrast-enhanced plan CT images.

MATERIALS/METHODS

A total of 65 cases treated with NCRT+ pembrolizumab followed by surgery were prospectively enrolled for analysis from 2019-2022. Each patient contains a contrast-enhanced plan CT and FDG PET images. 52 patients were randomly divided into training set and 13 patients were used as test set. The Extraction of radiomics features was performed using an open-source Python library PyRadiomics automatically. Features were computed according to the radiologist-drawn ROIs on both CT and PET images. In the feature selection stage least absolute shrinkage and selection operator (LASSO) was utilized on CT features and PET features separately. Four different machine learning models were implemented: Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF) and XGBoost (XGB). The features selected by LASSO regression were used as model input and the output of the model is "pCR" or "non-pCR". To find the optimal parameter, the 5-fold cross-validation method was used in the training stage. In this study, we use accuracy, sensitivity and specificity as the metrics to evaluate the performance of the model on the testing cohort. The predictive performance of the model was assessed using the area under curve (AUC) of the receiver operating characteristics curve (ROC).

RESULTS

Of the 65 cases treated with NCRT+pembrolizumab, 35 patients archived pCR (53.8%), and 30 archived non-pCR. 1684 radiomics features were extracted from each case, and half of them (842 features) were from CT and others were from PET. Among the machine learning models mentioned above SVM achieves the most promising performance on the evaluation metrics. Accuracy, sensitivity, specificity and AUC score on test set were 0.692, 0.833, 0.571 and 0.786 for CT features and 0.615, 0.667, 0.571 and 0.762 for PET features, respectively. For CT+FDG PET fused features accuracy, sensitivity, specificity and AUC score on test set were 0.769, 0.667, 0.857 and 0.833.

CONCLUSION

In this study, we performed several different machine learning models to predict the response to NCRT+ pembrolizumab among ESCC based on the extracted radiomics features from CT and FDG PET images. The best-performing model based on radiomics features of CT and PET images could identify non-pCR to NCRT + pembrolizumab in EC patients.

Prediction Analysis of Dose Verification Based on Plan Complexity Metrics during Radiotherapy

PURPOSE/OBJECTIVE(S)

Plan validation in radiotherapy includes pre-treatment and in-treatment validation. It is feasible to leverage plan complexity to optimize validation processes, because some research reports that the consistency between planning and measurement or execution decreases as plan complexity increases. Therefore, starting from the plan complexity, this study comprehensively and systematically explores these factors affecting whether the plan verification is passed or not and the strength of their correlations, so as to establish a regression model and optimize the verification process.

MATERIALS/METHODS

The IMRT and model-based validation information were retrospectively collected for patients who received tumor radiotherapy at our institution from January 2020 to May 2022. The seventy-eight metrics characterizing the plan complexity were calculated and checked for each plan by an in-house developed computing platform. The comparisons of plan verification results under different tumor species and different verification methods were carried out, and the plan complexity metrics was also compared. Subsequently, Spearman correlation analysis between plan complexity and plan validation under different tumor species, different verification methods and different evaluation indexes was analyzed to provide the basis for regression analysis.

RESULTS

One thousand two hundred twenty-six patients were enrolled in the study. The plans in Eclipse TPS were performed by Varian Edge and iX linear accelerators and their verification were executed by EPID, Delat4, and ArcCheck. The gamma index under evaluation index of 3%/3mm, 3%/2mm, 2%/2mm, 1%/1mm were respectively 97.4% (7.1%), 94.8% (10.9%), 86.1% (20.1%), 50.7% (22.6%). The γ and DD of EPID and Detla4 decreased with the increase of TH, and the change of DD was the most significant, while the DTA of Detla4 did not change significantly with TH, and the passing rate of DTA and γ in thoracic and abdominal was the highest in ArcCheck group. Contrast and Variance were the most different between tumor types. The pelvic MIs and MIa were larger than those planned for the other three sites. Except for head and neck CLS and MD, other metrics did not vary significantly among tumor species. The correlation between the metrics characterizing the static characteristics of leaves was more significant for head and neck tumors; the correlation between metrics characterizing the flux complexity were significantly different in pelvic. There was a correlation between plan complexity and γ indicators, and the overall strength was ArcCheck > EPID > Delta4 for head and neck, Delta4 > EPID and ArcCheck for thorax-abdomen, Delta4 and EPID > ArcCheck for pelvic, Delta4 > ArcCheck > EPID for arms and legs.

CONCLUSION

There was a correlation between different plan complexity metrics. Based on this study, it is feasible to predict the verification results based on these complexity metrics, but the regression models were respectively established according to tumor types and validation methods.

PD-L1 Inhibitors Combined with Thoracic Radiotherapy in First-Line Treatment of Extensive Stage Small Cell Lung Cancer: A Propensity Score-Matched, Real-World Study

PURPOSE/OBJECTIVE(S)

The CREST study showed that the addition of thoracic radiotherapy (TRT) could improve the survival of extensive stage small cell lung cancer (ES-SCLC), but whether TRT can bring survival benefit in the era of immunotherapy is controversial. This study aims to explore the efficacy and safety of adding TRT to the combination of PD-L1 inhibitors and chemotherapy.

MATERIALS/METHODS

Thepatients who received PD-L1 inhibitors combined with platinum-based chemotherapy as the first-line treatment of ES-SCLC from January 2019 to December 2021 were retrospectively collected. According to whether they received TRT, they were divided into two groups, and the follow-up analysis was performed. Propensity score matching (PSM) in with a 1:1 ratio was performed to balance the baseline characteristics of the two cohorts. The endpoints were progression-free survival (PFS) and OS.

RESULTS

A total of 211 patients with ES-SCLC were enrolled, of whom 70 (33.2%) patients received standard therapy plus TRT as first-line treatment, and 141 (66.8%) patients in the control group received PD-L1 inhibitors plus chemotherapy. After PSM, a total of 65 pairs of patients were enrolled in the analysis. There were no significant differences in baseline characteristics between the two groups of patients who received TRT and those who did not. In all patients, the median PFS (mPFS) in the TRT group and the non-TRT groupwere 9.5 months and 7.2 months, respectively, with HR = 0.60 (95% CI 0.41-0.87, p = 0.007). The median OS (mOS) in the TRT group was also significantly longer than that in the non-TRT group (24.1 months vs. 18.5 months, HR = 0.53, 95% CI 0.32-0.85, p = 0.009). Multivariable analysis showed that baseline liver metastasis and bone metastasis were independent prognostic factors for OS. In terms of safety, immunotherapy combined with thoracic radiotherapy increased the incidence of treatment-related pneumonia (p<0.001), most of which were grade 1-2.

CONCLUSION

This real-world study shows that adding TRT to durvalumab or atezolizumab plus chemotherapy significantly improves survival in ES-SCLC. It leads to more treatment-related pneumonia, but most of them can be relieved after symptomatic treatment. This treatment model deserves to be explored in prospective clinical trials.

Ultrasound-guided core-needle biopsy for peripheral pulmonary lesions: a systematic review and meta-analysis

AIM

To evaluate the diagnostic value and safety of ultrasound-guided core-needle biopsy for peripheral pulmonary lesions (PPLs).

MATERIALS AND METHODS

PubMed, EMBASE, and the Cochrane Library for relevant were searched for studies published up to June 2022. The diagnostic accuracy of US-guided percutaneous transthoracic needle biopsy (PTNB) for the diagnosis of PPLs was evaluated using pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive and negative likelihood ratios (PLR and NLR), and the area under the summary receiver operating characteristic curves value (SROC).

RESULTS

The search included 12 original studies (3,830 procedures). For US-guided PTNB, the pooled sensitivity and specificity for the diagnosis of PPLs were 0.93 (95% confidence interval [CI]: 0.91-0.94) and 0.99 (95% CI: 0.96-1.00), respectively. The pooled estimates of the PLR, NLR, and DOR were 134.88 (95% CI: 24.88-731.74), 0.07 (95% CI: 0.06-0.09), and 1,814.95 (95% CI: 333.62-9,873.76), respectively. The area under the SROC curve was 0.95 (95% CI: 0.93-0.97). The overall complication rate was 3.6% (136 of 3,830), including self-limited haemoptysis and asymptomatic pneumothorax, and only six cases of pneumothorax requiring chest tube drainage and one case of severe bleeding were reported.

CONCLUSIONS

US-guided core-needle biopsy is an excellent diagnostic tool for PPLs, with high accuracy and excellent technical performance and safety.

Nodal Response to Neo-Adjuvant Systemic Therapy Predicts Prognosis of cN3c Breast Cancer Patients Receiving Multidisciplinary Therapy

PURPOSE/OBJECTIVE(S)

cN3c breast cancer with ipsilateral supraclavicular (SCV) lymph nodal (SCLN) metastasis has a dismal prognosis. We investigated the survival outcomes, patterns and risks of recurrence in those patients after multidisciplinary therapy, as well as the predictors of candidates for SCV area boosting.

MATERIALS/METHODS

Consecutive cN3c breast cancer patients without distant metastases from January 2009 to December 2020 in our institution were retrospectively reviewed. Based on nodal response to neoadjuvant therapy (NAT), patients were categorized into three groups: clinical complete response (cCR) not achieved in SCLN (Group A, n = 66), SCLN cCR but axillary node (ALN) did not achieve pathological complete response (pCR, Group B, n = 34), cCR in SCLN and pCR in ALN (Group C, n = 13).

RESULTS

The median follow-up time was 32.7 months (range, 21.9-53.3months). The 5-year overall survival (OS) and recurrence-free survival (RFS) rates were 64.6% and 43.7% respectively. Multivariate analysis showed cumulative SCV dose and ypT stage, ALN response and SCV response to NAT were significantly associated with OS and RFS respectively. The 3-year for patients receiving the cumulative SCV dose of ≥60 Gy versus <60 Gy was 81.3% versus 69.0% (P = 0.042). Compared with Group A or B, Group C showed significantly improved RFS (3y-RFS: 53.8% vs 73.6% vs 100%, p = 0.003) and a numerically longer OS (3y-OS: 73.4% vs 86.7% vs 100%, p = 0.089). Meanwhile, Group C showed the lowest rate of DM as first failure (37.9 % vs 23.5% vs 0 in group A, B and C, respectively, p = 0.010). In patients of Group A, the 3-year OS rates for patients receiving the cumulative SCV dose of ≥60 Gy versus <60 Gy was 78.0% versus 57.3% (p = 0.029).

CONCLUSION

Nodal response to NAT is an independent prognostic factor for survival and pattern of failure. cN3c breast cancer patients with SCLN cCR and ALN pCR after NAT are potentially curable. A cumulative SCV dose of ≥60 Gy is positively associated with improved OS, especially in patients of SCLN without achieving cCR. Our data supports the perspective of optimizing radiotherapeutic strategy based on nodal response.

Observation of New Ω_{c}^{0} States Decaying to the Ξ_{c}^{+}K^{-} Final State

Two new excited states, Ω_{c}(3185)^{0} and Ω_{c}(3327)^{0}, are observed in the Ξ_{c}^{+}K^{-} invariant-mass spectrum using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1}. Five previously observed excited Ω_{c}^{0} states are confirmed, namely Ω_{c}(3000)^{0}, Ω_{c}(3050)^{0}, Ω_{c}(3065)^{0}, Ω_{c}(3090)^{0}, and Ω_{c}(3119)^{0}. The masses and widths of these seven states are measured with the highest precision to date.

Evidence of a J/ψK_{S}^{0} Structure in B^{0}→J/ψϕK_{S}^{0} Decays

An amplitude analysis of B^{0}→J/ψϕK_{S}^{0} decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 9  fb^{-1}, collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. Evidence with a significance of 4.0 standard deviations of a structure in the J/ψK_{S}^{0} system, named T_{ψs1}^{θ}(4000)^{0}, is seen, with its mass and width measured to be 3991_{-10}^{+12} _{-17}^{+9}  MeV/c^{2} and 105_{-25}^{+29} _{-23}^{+17}  MeV, respectively, where the first uncertainty is statistical and the second systematic. The T_{ψs1}^{θ}(4000)^{0} state is likely to be the isospin partner of the T_{ψs1}^{θ}(4000)^{+} state, previously observed in the J/ψK^{+} system of the B^{+}→J/ψϕK^{+} decay. When isospin symmetry for the charged and neutral T_{ψs1}^{θ}(4000) states is assumed, the signal significance increases to 5.4 standard deviations.

Measurement of the Ratios of Branching Fractions R(D^{*}) and R(D^{0})

The ratios of branching fractions R(D^{*})≡B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}μ^{-}ν[over ¯]_{μ}) and R(D^{0})≡B(B^{-}→D^{0}τ^{-}ν[over ¯]_{τ})/B(B^{-}→D^{0}μ^{-}ν[over ¯]_{μ}) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0  fb^{-1} of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ^{-}→μ^{-}ν_{τ}ν[over ¯]_{μ}. The measured values are R(D^{*})=0.281±0.018±0.024 and R(D^{0})=0.441±0.060±0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ=-0.43. The results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the standard model.

Measurement of the Prompt D^{0} Nuclear Modification Factor in p-Pb Collisions at sqrt[s_{NN}]=8.16 TeV

The production of prompt D^{0} mesons in proton-lead collisions in both the forward and backward rapidity regions at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=8.16  TeV is measured by the LHCb experiment. The nuclear modification factor of prompt D^{0} mesons is determined as a function of the transverse momentum p_{T}, and the rapidity in the nucleon-nucleon center-of-mass frame y^{*}. In the forward rapidity region, significantly suppressed production with respect to pp collisions is measured, which provides significant constraints on models of nuclear parton distributions and hadron production down to the very low Bjorken-x region of ∼10^{-5}. In the backward rapidity region, a suppression with a significance of 2.0-3.8 standard deviations compared to parton distribution functions in a nuclear environment expectations is found in the kinematic region of p_{T}>6  GeV/c and -3.25 Collapse

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Measurement of the Time-Integrated CP Asymmetry in D^{0}→K^{-}K^{+} Decays

The time-integrated CP asymmetry in the Cabibbo-suppressed decay D^{0}→K^{-}K^{+} is measured using proton-proton collision data, corresponding to an integrated luminosity of 5.7  fb^{-1} collected at a center-of-mass energy of 13 TeV with the LHCb detector. The D^{0} mesons are required to originate from promptly produced D^{*+}→D^{0}π^{+} decays, and the charge of the companion pion is used to determine the flavor of the charm meson at production. The time-integrated CP asymmetry is measured to be A_{CP}(K^{-}K^{+})=[6.8±5.4±1.6]×10^{-4} where the first uncertainty is statistical and the second systematic. The direct CP asymmetries in D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays, a_{K^{-}K^{+}}^{d} and a_{π^{-}π^{+}}^{d}, are derived by combining A_{CP}(K^{-}K^{+}) with the time-integrated CP asymmetry difference, ΔA_{CP}=A_{CP}(K^{-}K^{+})-A_{CP}(π^{-}π^{+}), and other inputs, giving a_{K^{-}K^{+}}^{d}=(7.7±5.7)×10^{-4},a_{π^{-}π^{+}}^{d}=(23.2±6.1)×10^{-4},with a correlation coefficient corresponding to ρ=0.88. The compatibility of these results with CP symmetry is 1.4 and 3.8 standard deviations for D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays, respectively. This is the first evidence for direct CP violation in a specific D^{0} decay.

Analysis of the value of echocardiographic parameters in the early diagnosis of preterm infants with bronchopulmonary dysplasia

OBJECTIVE

The objective of this study was to investigate the role of echocardiographic parameters in diagnosing bronchopulmonary dysplasia (BPD) in preterm infants.

PATIENTS AND METHODS

Ninety preterm infants with a gestational age of less than 32 weeks and a weight less than 1.5 kg, admitted to the neonatal intensive care unit of the hospital between January 2020 and January 2021, were selected for the study. The study subjects were divided into two groups: a BPD group (54 cases, observation group) and a non-BPD group (36 cases, control group). The correlation between tricuspid regurgitation (TR) velocity and BPD was investigated by detecting the cardiac function of preterm infants in both groups using a color Doppler ultrasound diagnostic instrument and analyzing the cardiac ultrasound results. The early prediction efficiency of TR velocity (m/s) for BPD was evaluated using the receiver operator characteristic (ROC) curve.

RESULTS

The incidence of patent ductus arteriosus (PDA) and pulmonary hypertension (PH) in the observation group was significantly higher than that in the control group. The levels of left ventricular ejection fraction (LVEF) and left ventricular shorting fraction (LVFS) were significantly lower than those in the control group (p < 0.05). The incidence of patent foramen ovale (PFO), atrial septal defect (ASD), and ventricular septal defect (VSD) in the observation group were not significantly different from the control group (p > 0.05). The proportion of tricuspid regurgitation in the observation group was significantly higher than that in the control group, and the TR velocity was significantly higher than that in the control group. The Spearman correlation analysis showed that TR velocity (m/s) was positively correlated to BPD severity (r = 0.379, p < 0.05). The area under the curve (AUC) for predicting BPD with TR velocity was 0.735. The sensitivity and specificity were 88.0% and 62.6%, respectively, when the TR velocity was 1.45 m/s.

CONCLUSIONS

Echocardiography is useful for understanding the degree of impaired cardiac function in preterm infants and for early detection of PH, which may reduce the mortality rate to a certain extent. The risk of BPD is significantly increased when TR velocity is higher than 1.45 m/s.

Measurement of the Branching Fractions B(B^{0}→pp[over ¯]pp[over ¯]) and B(B_{s}^{0}→pp[over ¯]pp[over ¯])

Searches for the rare hadronic decays B^{0}→pp[over ¯]pp[over ¯] and B_{s}^{0}→pp[over ¯]pp[over ¯] are performed using proton-proton collision data recorded by the LHCb experiment and corresponding to an integrated luminosity of 9  fb^{-1}. Significances of 9.3σ and 4.0σ, including statistical and systematic uncertainties, are obtained for the B^{0}→pp[over ¯]pp[over ¯] and B_{s}^{0}→pp[over ¯]pp[over ¯] signals, respectively. The branching fractions are measured relative to the topologically similar normalization decays B^{0}→J/ψ(→pp[over ¯])K^{*0}(→K^{+}π^{-}) and B_{s}^{0}→J/ψ(→pp[over ¯])⁢ϕ(→K^{+}K^{-}). The branching fractions are measured to be B(B^{0}→pp[over ¯]pp[over ¯])=(2.2±0.4±0.1±0.1)×10^{-8} and B(B_{s}^{0}→pp[over ¯]pp[over ¯])=(2.3±1.0±0.2±0.1)×10^{-8}. In these measurements, the first uncertainty is statistical, the second is systematic, and the third one is due to the external branching fraction of the normalization channel.

Observation of a Resonant Structure near the D_{s}^{+}D_{s}^{-} Threshold in the B^{+}→D_{s}^{+}D_{s}^{-}K^{+} Decay

An amplitude analysis of the B^{+}→D_{s}^{+}D_{s}^{-}K^{+} decay is carried out to study for the first time its intermediate resonant contributions, using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A near-threshold peaking structure, referred to as X(3960), is observed in the D_{s}^{+}D_{s}^{-} invariant-mass spectrum with significance greater than 12 standard deviations. The mass, width, and the quantum numbers of the structure are measured to be 3956±5±10  MeV, 43±13±8  MeV, and J^{PC}=0^{++}, respectively, where the first uncertainties are statistical and the second systematic. The properties of the new structure are consistent with recent theoretical predictions for a state composed of cc[over ¯]ss[over ¯] quarks. Evidence for an additional structure is found around 4140 MeV in the D_{s}^{+}D_{s}^{-} invariant mass, which might be caused either by a new resonance with the 0^{++} assignment or by a J/ψϕ↔D_{s}^{+}D_{s}^{-} coupled-channel effect.

Strong Constraints on Jet Quenching in Centrality-Dependent p+Pb Collisions at 5.02 TeV from ATLAS

Jet quenching is the process of color-charged partons losing energy via interactions with quark-gluon plasma droplets created in heavy-ion collisions. The collective expansion of such droplets is well described by viscous hydrodynamics. Similar evidence of collectivity is consistently observed in smaller collision systems, including pp and p+Pb collisions. In contrast, while jet quenching is observed in Pb+Pb collisions, no evidence has been found in these small systems to date, raising fundamental questions about the nature of the system created in these collisions. The ATLAS experiment at the Large Hadron Collider has measured the yield of charged hadrons correlated with reconstructed jets in 0.36  nb^{-1} of p+Pb and 3.6  pb^{-1} of pp collisions at 5.02 TeV. The yields of charged hadrons with p_{T}^{ch}>0.5  GeV near and opposite in azimuth to jets with p_{T}^{jet}>30 or 60 GeV, and the ratios of these yields between p+Pb and pp collisions, I_{pPb}, are reported. The collision centrality of p+Pb events is categorized by the energy deposited by forward neutrons from the struck nucleus. The I_{pPb} values are consistent with unity within a few percent for hadrons with p_{T}^{ch}>4  GeV at all centralities. These data provide new, strong constraints that preclude almost any parton energy loss in central p+Pb collisions.

[Impact of immunosuppression intensified conditioning regimen for patients with strong positive pre-transplantation donor-specific anti-HLA antibodies (DSAs) undergoing haploidentical hematopoietic stem cell transplantation]

Objective: To explore the efficacy of immunosuppression intensified conditioning regimen in patients who have strongly positive donor-specific Anti-HLA antibodies (DSAs) and received a haploidentical hematopoietic stem cell transplantation (haplo-HSCT) . Methods: Clinical data of 10 patients with strongly positive pretransplant DSAs (defined as MFI ≥10000) were retrospectively analyzed in this study. All of them received a haplo-HSCT in the Hematology Department of Shanghai Zhaxin Traditional Chinese & Western Medicine Hospital. Results: ① Of all ten patients, three were males, and seven were females, with a median age of 53.5 (36-64) years. Of the 10 patients, three were diagnosed with acute myeloid leukemia, two were myelodysplastic syndromes (MDS), two were chronic myelomonocytic leukemia (CMML), two were in an accelerated phase of chronic myeloid leukemia (CML-AP), and one was primary myelofibrosis (PMF). ② Conditioning regimen consisted of fludarabine (Flu) /busulfan (Bu) combined with whole-body irradiation (TBI) /cyclophosphamide (Cy). ③ On the seventh day after transplantation, the median pretransplant DSA level was MFI 15 999 (10 210-23 417) and 10 787 (0-22 720). ④ Eight patients acquired hematopoietic reconstitution; the median time of neutrophil engraftment was 14 (10-16) days; and 18 (14-20) days for platelet engraftment. After a median follow-up of 12.5 (1.5-27) months, primary graft failure was found in one patient and another with poor graft function. Seven patients remained in a disease remission state, and all were DSA-negative. Conclusions: An intensified immunosuppression conditioning regimen can efficiently decrease the level of donor-specific anti-HLA antibodies (DSAs), leading to good short-term efficacy.

Search for Heavy Neutral Leptons in Decays of W Bosons Using a Dilepton Displaced Vertex in sqrt[s]=13 TeV pp Collisions with the ATLAS Detector

A search for a long-lived, heavy neutral lepton (N) in 139  fb^{-1} of sqrt[s]=13  TeV pp collision data collected by the ATLAS detector at the Large Hadron Collider is reported. The N is produced via W→Nμ or W→Ne and decays into two charged leptons and a neutrino, forming a displaced vertex. The N mass is used to discriminate between signal and background. No signal is observed, and limits are set on the squared mixing parameters of the N with the left-handed neutrino states for the N mass range 3  GeV Collapse

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Evidence for Modification of b Quark Hadronization in High-Multiplicity pp Collisions at sqrt[s]=13 TeV

The production rate of B_{s}^{0} mesons relative to B^{0} mesons is measured by the LHCb experiment in pp collisions at a center-of-mass energy sqrt[s]=13  TeV over the forward rapidity interval 2 Collapse

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Test of CP Invariance in Higgs Boson Vector-Boson-Fusion Production Using the H→γγ Channel with the ATLAS Detector

A test of CP invariance in Higgs boson production via vector-boson fusion has been performed in the H→γγ channel using 139  fb^{-1} of proton-proton collision data at sqrt[s]=13  TeV collected by the ATLAS detector at the LHC. The optimal observable method is used to probe the CP structure of interactions between the Higgs boson and electroweak gauge bosons, as described by an effective field theory. No sign of CP violation is observed in the data. Constraints are set on the parameters describing the strength of the CP-odd component in the coupling between the Higgs boson and the electroweak gauge bosons in two effective field theory bases: d[over ˜] in the HISZ basis and c_{HW[over ˜]} in the Warsaw basis. The results presented are the most stringent constraints on CP violation in the coupling between Higgs and weak bosons. The 95% C.L. constraint on d[over ˜] is derived for the first time and the 95% C.L. constraint on c_{HW[over ˜]} has been improved by a factor of 5 compared to the previous measurement.

Test of Lepton Universality in b→sℓ^{+}ℓ^{-} Decays

The first simultaneous test of muon-electron universality using B^{+}→K^{+}ℓ^{+}ℓ^{-} and B^{0}→K^{*0}ℓ^{+}ℓ^{-} decays is performed, in two ranges of the dilepton invariant-mass squared, q^{2}. The analysis uses beauty mesons produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9  fb^{-1}. Each of the four lepton universality measurements reported is either the first in the given q^{2} interval or supersedes previous LHCb measurements. The results are compatible with the predictions of the Standard Model.

Randomized phase II adjuvant trial to compare two treatment durations of icotinib (2 years versus 1 year) for stage II-IIIA EGFR-positive lung adenocarcinoma patients (ICOMPARE study)

BACKGROUND

Despite the prolonged median disease-free survival (DFS) by adjuvant targeted therapy in non-small-cell lung cancer patients with epidermal growth factor receptor (EGFR) mutations, the relationship between the treatment duration and the survival benefits in patients remains unknown.

PATIENTS AND METHODS

In this multicenter, randomized, open-label, phase II trial, eligible patients aged 18-75 years with EGFR-mutant, stage II-IIIA lung adenocarcinoma and who had not received adjuvant chemotherapy after complete tumor resection were enrolled from eight centers in China. Patients were randomly assigned (1 : 1) to receive either 1-year or 2-year icotinib (125 mg thrice daily). The primary endpoint was DFS assessed by investigator. The secondary endpoints were overall survival (OS) and safety. This study was registered at ClinicalTrials.gov (NCT01929200).

RESULTS

Between September 2013 and October 2018, 109 patients were enrolled (1-year group, n = 55; 2-year group, n = 54). Median DFS was 48.9 months [95% confidence interval (CI) 33.1-70.1 months] in the 2-year group and 32.9 months (95% CI 26.6-44.8 months) in the 1-year group [hazard ratio (HR) 0.51; 95% CI 0.28-0.94; P = 0.0290]. Median OS for patients was 75.8 months [95% CI 64.4 months-not evaluable (NE)] in the 2-year group and NE (95% CI 66.3 months-NE) in the 1-year group (HR 0.34; 95% CI 0.13-0.95; P = 0.0317). Treatment-related adverse events (TRAEs) were observed in 41 of 55 (75%) patients in the 1-year group and in 36 of 54 (67%) patients in the 2-year group. Grade 3-4 TRAEs occurred in 4 of 55 (7%) patients in the 1-year group and in 3 of 54 (6%) patients in the 2-year group. No treatment-related deaths or interstitial lung disease was reported.

CONCLUSIONS

Two-year adjuvant icotinib was shown to significantly improve DFS and provide an OS benefit in EGFR-mutant, stage II-IIIA lung adenocarcinoma patients compared with 1-year treatment in this exploratory phase II study.

Analysis of the factors influencing male infertility of reproductive age in Jinan

OBJECTIVE

The World Health Organization (WHO) defines infertility as a person failing to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse. Infertility includes female infertility and male infertility. The aim of this paper is to study the etiology of infertility and related influencing factors in men of reproductive age in Jinan.

PATIENTS AND METHODS

In this study, 172 male infertile patients who attended the Department of Assisted Reproduction of Shandong Provincial Maternal and Child Health Hospital in Shandong, China and the Infertility Clinic of Jinan Central Hospital in Shandong, China from August 2021 to April 2022 are selected as the study population (infertility group). A convenience sampling method is used to select 257 men from couples attending the Obstetrics Department of Qilu Hospital in Shandong, China, the Obstetrics Department of the Second Hospital of Shandong University in Shandong, China, and the Obstetrics Department of Maternal and Child Health Hospital in Shandong, China from October 2021 to February 2022 as the study subjects (control group). A self-designed questionnaire is used to conduct the survey, which includes basic personal information, lifestyle information, marital and family-related information, and one-way and multi-way logistic regression analyses are performed.

RESULTS

The average age of the case group and the control group are 34.03±5.13 years old and 33.61±8.18 years old; the average height is 175.80±5.91 cm and 176.78±5.25 cm; the average weight is 80.28±14.70 kg and 83.09±45.36 kg. The differences in age, height, and weight between the case group and the control group are not statistically significant by t-test. Moderate oligospermia is the predominant cause of infertility in men of reproductive age in Jinan. A multifactorial logistic regression analysis yields that academic qualifications (OR=2.518, 95% CI: 1.023 to 6.196), coffee consumption (OR=7.692, 95% CI: 1.623 to 36.460), living in a room that had been renovated within a period of time (OR=2.769, 95% CI: 1.104 to 6.949), stress level (OR=47.280, 95% CI: 23.656-94.494), quality of sexual life (OR=3.352, 95% CI: 1.331-8.442), and duration of couple separation (OR=3.851, 95% CI: 1.094-13.557) are the main risk factors for infertility in men of reproductive age in Jinan.

CONCLUSIONS

In this study, a total of 6 risk factors are screened for male infertility in Jinan in the reproductive age, including high academic qualifications, coffee consumption, living in a room that has finished renovation within 3 months, high stress, poor quality of sexual life, and long spousal separation. Three factors can be controlled, avoided, or reduced through personal actions; the factors are coffee consumption, living in a room that has finished renovation within 3 months, and high stress, all of which may reduce the level of male reproductive health.

First Observation of a Doubly Charged Tetraquark and Its Neutral Partner

A combined amplitude analysis is performed for the decays B^{0}→D[over ¯]^{0}D_{s}^{+}π^{-} and B^{+}→D^{-}D_{s}^{+}π^{+}, which are related by isospin symmetry. The analysis is based on data collected by the LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV. The full data sample corresponds to an integrated luminosity of 9  fb^{-1}. Two new resonant states with masses of 2.908±0.011±0.020  GeV and widths of 0.136±0.023±0.013  GeV are observed, which decay to D_{s}^{+}π^{+} and D_{s}^{+}π^{-} respectively. The former state indicates the first observation of a doubly charged open-charm tetraquark state with minimal quark content [cs[over ¯]ud[over ¯]], and the latter state is a neutral tetraquark composed of [cs[over ¯]u[over ¯]d] quarks. Both states are found to have spin-parity of 0^{+}, and their resonant parameters are consistent with each other, which suggests that they belong to an isospin triplet.

Search for Rare Decays of D^{0} Mesons into Two Muons

A search for the very rare D^{0}→μ^{+}μ^{-} decay is performed using data collected by the LHCb experiment in proton-proton collisions at sqrt[s]=7, 8, and 13 TeV, corresponding to an integrated luminosity of 9  fb^{-1}. The search is optimized for D^{0} mesons from D^{*+}→D^{0}π^{+} decays but is also sensitive to D^{0} mesons from other sources. No evidence for an excess of events over the expected background is observed. An upper limit on the branching fraction of this decay is set at B(D^{0}→μ^{+}μ^{-})<3.1×10^{-9} at a 90% C.L. This represents the world's most stringent limit, constraining models of physics beyond the standard model.

Nuclear Modification Factor of Neutral Pions in the Forward and Backward Regions in p-Pb Collisions

The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.16 TeV with the LHCb detector. The π^{0} production cross section is measured differentially in transverse momentum (p_{T}) for 1.5 Collapse

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First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment

We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03)  ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3)  events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47}  cm^{2} for a WIMP mass of 28  GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.

[Clinical analysis of immunotherapy rechallenge in advanced gastric cancer]

Objective: To evaluate the efficacy and influencing factors of programmed death protein 1 (PD-1) monoclonal antibody rechallenge therapy in advanced gastric cancer (GC). Methods: The clinical data of patients with advanced GC who were treated with anti-PD-1 rechallenge in Henan Cancer Hospital from January 2020 to December 2021 were collected retrospectively. The progression-free survival (PFS) was defined as the time from the first or second used of anti-PD-1 treatment to the date of disease progression or the last follow-up, named PFS(1) and PFS(2), respectively. Kaplan-Meier method and Log rank test were used for survival analysis, Cox proportional hazard model was used to analyze the influencing factors. Results: A total of 60 patients with anti-PD-1 rechallenge therapy were collected, the median follow-up time was 12.2 months. The median progression-free survival (PFS(2)) of anti-PD-1 rechallenge therapy was 2.9 months, the objective response rate (ORR) was 16.7%, and the disease control rate (DCR) was 55.0%. The median PFS(2) of the first and second anti-PD-1 identical and different rechallenge treatment was 3.5 months and 1.9 months (P=0.007) respectively. The median PFS(2) of positive PD-L1 expression in rechallenge therapy was 3.4 months, ORR was 22.7%, and DCR was 63.6%; the median PFS(2) was 4.5 months, ORR was 27.3%, and DCR was 54.5% in patients with median PFS(1)≥6 months. Multivariate analysis showed that peritoneal metastasis was independently associated with anti-PD-1 rechallenge therapy with PFS(2) (HR=2.327, 95% CI, 1.066-5.082, P=0.034). The incidence of adverse reactions in grade 1-2 and grade 3-4 of anti-PD-1 rechallenge therapy was 83.3%, and 35.0%, respectively, and the safety was controllable. Conclusion: Rechallenge therapy with anti-PD-1 is a feasible treatment in advanced GC, but the screening of suitable population for rechallenge therapy still needs prospective data analysis and verification.