Radiotherapy For Esophageal Cancer Research Articles

PO-1390 Definitive radiotherapy in T1N0M0 esophageal cancer: a multicenter retrospective study (KROG 21-10)

PO-1390 Definitive radiotherapy in T1N0M0 esophageal cancer: a multicenter retrospective study (KROG 21-10)

Association of survival with adjuvant radiotherapy for pN0 esophageal cancer

Introduction: This study was conducted to elucidate the link between adjuvant radiotherapy and survival in pathologic node-negative (pN0) esophageal cancer patients with upfront esophagectomy. Methods: From 2000 to 2016, patients with pN0 esophageal cancer who underwent upfront esophagectomy were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The association of high-risk covariates with survival after adjuvant radiotherapy was evaluated using propensity score matching and multivariate analysis. Results: We identified 3197 patients, 321 (10.0%) underwent postoperative radiotherapy and 2876 (90.0%) underwent esophagectomy alone. In the unmatched cohort, postoperative radiotherapy was associated with a statistically significant but modest absolute decrease in survival outcomes (P < 0.001). In the matched cohort, the survival differences disappeared. Additionally, adjuvant radiotherapy was linked to a 5-year overall survival (OS) benefit for patients with the pT3-4N0 disease (34.8% vs. 27.7%; P = 0.008). Adjuvant radiotherapy for pT3-4N0 disease with tumor length ≥3 cm, adenocarcinoma, and evaluated lymph node count <12 was shown to independently function as a risk factor for improved OS, as per a multivariate analysis (P < 0.01). Conclusions: This population-based trial showed that high-risk patients with pT3-4N0 esophageal cancer had better OS following upfront esophagectomy followed by radiotherapy therapy. This discovery may have major significance in the use of adjuvant radiotherapy following upfront esophagectomy in patients with pN0 esophageal cancer.

Analysis of particle therapy registries based on a unified treatment policy for esophageal cancer.

This study aimed to evaluate the efficacy and safety of particle therapy (proton beam therapy and carbon-ion radiotherapy) for esophageal cancer by analyzing prospective nationwide registry data from particle therapy facilities throughout Japan. Patients diagnosed with esophageal cancer who received particle therapy between May 2016 and June 2018 were recruited from the registries of 12 particle therapy centers in Japan. Eventually, we enrolled 174 patients who met the inclusion criteria. Of the 174 patients, 137 (78.7%) were male, with a median age of 69years (range: 41-88years). Clinical stages included I (n = 55; 31.6%), II (n = 31; 17.8%), III (n = 82; 47.1%), IV (n = 3; 1.7%) and unknown (n = 3; 1.7%) (Union for International Cancer Control, seventh edition), and the median follow-up period was 908days (range: 76-1669days) for all patients. The 3-year overall survival (OS) rate, the 3-year progression-free survival (PFS) rate and the 3-year local control (LC) rates were 60.5, 53.2 and 72.7%, respectively. For each clinical stage, the 3-year OS rates were I, 84.8%; II, 60.3% and III, 42.9%; the 3-year PFS rates were I, 71.9%; II, 58.3% and III, 37.0% and the 3-year LC were I, 78.4%; II, 79.8% and III, 65.2%, respectively. Notably, four patients (2.3%) with ≥Grade 3 cardiopulmonary toxicities were observed (Common Terminology Criteria for Adverse Events, version 5.0). Our study showed that particle therapy for esophageal cancer has lower rates of adverse cardiopulmonary events than X-ray radiotherapy.

Intrafraction motion analysis in online adaptive radiotherapy for esophageal cancer.

Intrafraction motion during magnetic resonance (MR)-guided dose delivery of esophageal cancer tumors was retrospectively analyzed. Deformable image registration of cine-MR series resulted in gross tumor volume motion profiles in all directions, which were subsequently filtered to isolate respiratory and drift motion. A large variability in intrafraction motion patterns was observed between patients. Median 95% peak-to-peak motion was 7.7 (3.7 - 18.3) mm, 2.1 (0.7 - 5.7) mm and 2.4 (0.5 - 5.6) mm in cranio-caudal, left-right and anterior-posterior directions, relatively. Furthermore, intrafraction drift was generally modest (<5mm). A patient specific approach could lead to very small margins (<3mm) for most patients.

Factors Related to Difficulty in Endoscopic Submucosal Dissection for Superficial Esophageal Cancer

Background: Endoscopic submucosal dissection (ESD) for superficial esophageal cancer is technically challenging, and research on predictive factors related to the difficulty in the procedure is limited. This study aimed to investigate the factors predicting the difficulty in esophageal ESD. Methods: This retrospective study analyzed 303 lesions treated at our institution between April 2005 and June 2021. The following 13 factors were evaluated: sex, age, tumor location, tumor localization, macroscopic type, tumor size, tumor circumference, preoperative diagnosis of histological type, preoperative diagnosis of invasion depth, previous radiotherapy for esophageal cancer, metachronous lesion located close to post-ESD scar, operator’s skill, and use of a clip-and-thread traction method. Difficult esophageal ESD cases were defined as those requiring long procedure time (>120 min). Results: Fifty-one lesions (16.8%) met the defined criterion for difficult cases of esophageal ESD. Logistic regression analysis identified tumor size larger than 30 mm (odds ratio: 9.17, 95% confidence interval: 4.27–19.69, p < 0.001) and tumor circumference more than half that of the esophagus (odds ratio 2.53, 95% confidence interval: 1.15–5.54, p = 0.021) as independent predictive factors related to difficulty in esophageal ESD. Conclusion: Tumor size larger than 30 mm and tumor circumference more than half that of the esophagus can predict difficulty in performing esophageal ESD. This knowledge can provide useful information for developing ESD strategies and selecting a suitable operator on a case-by-case basis to achieve favorable clinical outcomes.

Risk and prognosis of secondary thoracic cancers after radiation therapy for esophageal cancer.

Radiation therapy (RT) is a crucial modality for the local control of esophageal cancer (EC), but the effect of RT on the development of secondary thoracic malignancies is still unclear. This study aims to identify the association between RT for the treatment of primary EC and subsequent secondary thoracic cancer (STC). The primary EC patients were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Fine-Gray competing risk regression and standardized incidence ratio (SIR) were used to evaluate the radiotherapy-associated cancer risk. Overall survival (OS) was compared by Kaplan-Meier analysis. A total of 40255 EC patients from the SEER database were identified, of which 17055 patients (42.37%) did not receive radiotherapy (NRT) and 23200 patients (57.63%) had been treated with RT. After 12months of latency, 162 patients (0.95%) in the NRT group and 272 patients (1.17%) in the RT group developed STC. The incidences of the RT group were significantly higher than the NRT group. Patients who have primary EC were at an increased risk of developing STC (SIR=1.79, 95% CI: 1.63-1.96). The SIR of STC was 1.37 (95% CI: 1.16-1.60) in the NRT group and 2.10 (95% CI: 1.87-2.34) in the RT group. The OS of STC patients in the RT group was significantly lower than the NRT group (P=0.006). The RT for primary EC was associated with higher risks of developing STC than patients unexposed to radiotherapy. The EC patients treated with RT, especially young patients, require long-term monitoring of the risk of STC.

Improving CBCT image quality to the CT level using RegGAN in esophageal cancer adaptive radiotherapy

ObjectiveThis study aimed to improve the image quality and CT Hounsfield unit accuracy of daily cone-beam computed tomography (CBCT) using registration generative adversarial networks (RegGAN) and apply synthetic CT (sCT) images to dose calculations in radiotherapy.MethodsThe CBCT/planning CT images of 150 esophageal cancer patients undergoing radiotherapy were used for training (120 patients) and testing (30 patients). An unsupervised deep-learning method, the 2.5D RegGAN model with an adaptively trained registration network, was proposed, through which sCT images were generated. The quality of deep-learning-generated sCT images was quantitatively compared to the reference deformed CT (dCT) image using mean absolute error (MAE), root mean square error (RMSE) of Hounsfield units (HU), and peak signal-to-noise ratio (PSNR). The dose calculation accuracy was further evaluated for esophageal cancer radiotherapy plans, and the same plans were calculated on dCT, CBCT, and sCT images.ResultsThe quality of sCT images produced by RegGAN was significantly improved compared to the original CBCT images. ReGAN achieved image quality in the testing patients with MAE sCT vs. CBCT: 43.7 ± 4.8 vs. 80.1 ± 9.1; RMSE sCT vs. CBCT: 67.2 ± 12.4 vs. 124.2 ± 21.8; and PSNR sCT vs. CBCT: 27.9 ± 5.6 vs. 21.3 ± 4.2. The sCT images generated by the RegGAN model showed superior accuracy on dose calculation, with higher gamma passing rates (93.3 ± 4.4, 90.4 ± 5.2, and 84.3 ± 6.6) compared to original CBCT images (89.6 ± 5.7, 85.7 ± 6.9, and 72.5 ± 12.5) under the criteria of 3 mm/3%, 2 mm/2%, and 1 mm/1%, respectively.ConclusionThe proposed deep-learning RegGAN model seems promising for generation of high-quality sCT images from stand-alone thoracic CBCT images in an efficient way and thus has the potential to support CBCT-based esophageal cancer adaptive radiotherapy.

Retracted: Serum MMP-9 and SAA in the Diagnosis of Severe Pneumonia Caused by Radiotherapy of Esophageal Cancer.

[This retracts the article DOI: 10.1155/2021/6032546.].

Retracted: Risk Factors of Acute Radiation-Induced Lung Injury Induced by Radiotherapy for Esophageal Cancer.

[This retracts the article DOI: 10.1155/2022/2416196.].

The Efficacy and Safety of Oral Nutrient Solution Supplementation in Patients with Esophageal Cancer under Nutritional, Psychological, Physical, and Prognostic Survival Differences.

Inflammasomes are massive intracellular multiprotein signaling complexes produced in the cytosolic compartment. Tumor etiology involves dysregulation of NLRP3 inflammasome activation. Current studies are being conducted to ascertain the effectiveness and safety of oral nutrient solution supplementation in patients with esophageal cancer based on the current understanding of the role of the NLRP3 inflammasome in possible cancer promotion and therapy. This study examines how oral nutrient solution supplement therapy affects patients receiving radiotherapy and chemotherapy for esophageal cancer in terms of nutrition, physical composition, quality of life, psychology, prognosis, and survival. A total of 120 patients with esophageal cancer admitted to our hospital from March 2020 to January 2021 were selected for the current study. The selected 120 patients are divided into nutritional supplement and traditional groups according to the random number table method, with 60 cases in each group. The nutritional supplement group received an oral nutritional solution, whereas the conventional group received the ordinary dietary intervention. Since radiotherapy can potentially damage healthy tissue with short- and long-term negative effects. Inflammatory reactions are a common component of adverse effects of early and late ionizing radiation. Oral nutrient solution supplement therapy for patients with esophageal cancer after radiotherapy and chemotherapy can significantly improve the levels of blood nutrients, later physical components, and quality of life of patients.

Retracted: Analysis of Curative Effect and Prognostic Factors of Radiotherapy for Esophageal Cancer Based on the CNN

Retracted: Analysis of Curative Effect and Prognostic Factors of Radiotherapy for Esophageal Cancer Based on the CNN

Baseline cardiac risk profile determines radiation-induced cardiac toxicity in patients with mid-lower esophageal cancer

Abstract Background: The radiotherapy techniques are evolving. Besides optimal tumour coverage, considering organs at risk (OAR) is pertinent to radiation oncologists. In mid-lower esophageal cancer (MLEC) radiotherapy, heart is the main OAR. Studies on excess absolute risk (EAR) of cardiovascular disease (CVD) in MLEC radiotherapy are limited in the main literature. Therefore, this study was conducted to estimate the EAR of CVD in patients with MLEC treated with the intensity-modulated radiation therapy (IMRT) technique. Results: Family history of heart disease and smoking increased the EAR of CVD significantly compared to the cholesterol and high-sensitivity C-reactive protein. The 10-year EAR of the high-risk group was more than four times of the low-risk group at all ages. In the low-risk group, EAR of CVD after radiotherapy of esophageal cancer can increase by up to 9·1%, while in the high-risk group, EAR increased by 34·89%. Conclusions: Adding the baseline CVD risk factors improved the estimation of EAR of heart disease after MLEC radiotherapy with the IMRT technique.

Identification of the miRNA-mRNA regulatory network associated with radiosensitivity in esophageal cancer based on integrative analysis of the TCGA and GEO data

BackgroundThe current study set out to identify the miRNA-mRNA regulatory networks that influence the radiosensitivity in esophageal cancer based on the The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases.MethodsFirstly, esophageal cancer-related miRNA-seq and mRNA-seq data were retrieved from the TCGA database, and the mRNA dataset of esophageal cancer radiotherapy was downloaded from the GEO database to analyze the differential expressed miRNAs (DEmiRNAs) and mRNAs (DEmRNAs) in radiosensitive and radioresistant samples, followed by the construction of the miRNA-mRNA regulatory network and Gene Ontology and KEGG enrichment analysis. Additionally, a prognostic risk model was constructed, and its accuracy was evaluated by means of receiver operating characteristic analysis.ResultsA total of 125 DEmiRNAs and 42 DEmRNAs were closely related to the radiosensitivity in patients with esophageal cancer. Based on 47 miRNA-mRNA interactions, including 21 miRNAs and 21 mRNAs, the miRNA-mRNA regulatory network was constructed. The prognostic risk model based on 2 miRNAs (miR-132-3p and miR-576-5p) and 4 mRNAs (CAND1, ZDHHC23, AHR, and MTMR4) could accurately predict the prognosis of esophageal cancer patients. Finally, it was verified that miR-132-3p/CAND1/ZDHHC23 and miR-576-5p/AHR could affect the radiosensitivity in esophageal cancer.ConclusionOur study demonstrated that miR-132-3p/CAND1/ZDHHC23 and miR-576-5p/AHR were critical molecular pathways related to the radiosensitivity of esophageal cancer.

Toxicity profile of combined immune checkpoint inhibitors and thoracic radiotherapy in esophageal cancer: A meta-analysis and systematic review.

Therapies based on the combination of immune checkpoint inhibitors (ICIs) and thoracic radiotherapy (TRT) are transforming the treatment landscape of esophageal cancer. Nevertheless, the available data on adverse events (AEs) mainly stemmed from several prospective clinical trials and retrospective studies, in which, AE data are often handled and reported with less rigor than the primary beneficial outcomes of the study. Thus, we conducted a systematic review to investigate the toxicity spectrum of these novel regimens. We searched for all prospective clinical trials investigating the role of ICIs combined with TRT published between January 2010 and August 2022. Study articles and conference proceedings involving esophageal cancers and reporting the overall incidence or details of treatment-related AEs (trAEs) were synthesized to determine the toxicity profile of combination treatment. We compared trAEs between cancer type, programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors, and between sequential and concurrent administration of ICIs and TRT to identify potentially high-risk patients. We obtained toxicity data from 14 clinical trials involving 863 patients. The pooled overall incidence was 88.97% for any-grade trAEs and 18.48% for high-grade trAEs. The three most frequent non-hematologic any-grade trAEs were reactive cutaneous capillary endothelial proliferation (RCCEP, 63.80%), esophagitis (51.54%), and fatigue (33.63%). Meanwhile, RCCEP (15.69%) was the most common non-hematologic high-grade trAE, followed by nausea (4.91%) and anorexia (3.81%). The occurrence rates of any-grade and high-grade pneumonitis were 10.82% and 0.66%, respectively. In subgroup analysis, the toxicity profiles of PD-1 and PD-L1 inhibitors were mostly similar, except for any-grade pneumonitis (15.20% vs 4.88%, p=0.03) and high-grade leukopenia (6.25% vs 59.09%, p=0.00). In addition, concurrent treatment seemed to have a higher incidence of any-grade trAEs (95.20% vs 70.85%, p=0.03) compared with sequential treatment. ESCC seems to have higher incidence of any-grade hypothyroidism (22.55% vs 8.96%, p=0.049) compared to EAC. Our study is the first systematic review to provide a toxicity profile of trAEs in esophageal cancer patients who received ICIs combined with TRT. Most AEs of this combination treatment are tolerable, although the incidence of any-grade trAEs was higher in the concurrent group. The difference in any-grade pneumonitis between PD-1 and PD-L1 inhibitor groups needs further validation in a large clinical trial.

Robustness assessment of clinical adaptive proton and photon radiotherapy for oesophageal cancer in the model-based approach

PurposeIn the Netherlands, oesophageal cancer (EC) patients are selected for intensity modulated proton therapy (IMPT) using the expected normal tissue complication probability reduction (ΔNTCP) when treating with IMPT compared to volumetric modulated arc therapy (VMAT). In this study, we evaluate the robustness of the first EC patients treated with IMPT in our clinic in terms of target and organs-at-risk (OAR) dose with corresponding NTCP, as compared to VMAT. Materials and MethodsFor 20 consecutive EC patients, clinical IMPT and VMAT plans were created on the average planning 4DCT. Both plans were robustly evaluated on weekly repeated 4DCTs and if target coverage degraded, replanning was performed. Target coverage was evaluated for complete treatment trajectories with and without replanning. The planned and accumulated mean lung dose (MLD) and mean heart dose (MHD) were additionally evaluated and translated into NTCP. ResultsReplanning in the clinic was performed more often for IMPT (15x) than would have been needed for VMAT (8x) (p = 0.11). Both adaptive treatments would have resulted in adequate accumulated target dose coverage. Replanning in the first week of treatment had most clinical impact, as anatomical changes resulting in insufficient accumulated target coverage were already observed at this stage. No differences were found in MLD between the planned dose and the accumulated dose. Accumulated MHD differed from the planned dose (p < 0.001), but since these differences were similar for VMAT and IMPT (1.0 and 1.5 Gy, respectively), the ΔNTCP remained unchanged. ConclusionFollowing an adaptive clinical workflow, adequate target dose coverage and stable OAR doses with corresponding NTCPs was assured for both IMPT and VMAT.

Usefulness of the G8 Screening Tool in Determining Treatment Strategies for Definitive Radiotherapy of Esophageal Cancer in the Elderly

<h3>Purpose/Objective(s)</h3> Recent clinical trials for chemoradiotherapy (CRT) in esophageal cancer, such as ARTDECO and CONCORDE used elective nodal irradiation (ENI). However, it is often difficult to perform standard CRT for the elderly in the real world, and also there is no clear consensus on the criteria for this decision. Recently the G8 screening tool for geriatric assessment has been attracting attention in the oncology field. This study aimed to investigate the relationship between the treatment strategy of definitive RT and the G8 score for esophageal cancer in the elderly. <h3>Materials/Methods</h3> We analyzed 81 esophageal cancer patients aged ≥65 years (27 aged ≤74 years, 26 aged 75-79 years, and 28 aged ≥80 years) who received definitive RT between 2018 and 2021. The G8 screening tool was performed at the first visit to the radiation oncology department. The treatment strategy was decided by a conference between the radiation oncologist and esophageal surgeon, and the G8 score was not used to determine the treatment strategy. Standard RT was defined as ENI and a total dose ≥50 Gy, and standard chemotherapy (ChT) was defined as two cycles of platinum (70 mg/m2) and 5FU (700 mg/m2 for 4 days) concurrently. Patients who underwent standard RT and standard ChT were defined as the standard group and the rest as the non-standard group. The Mann-Whitney U test was used to compare the two groups, and statistical significance was set at p<0.05. The Receiver Operating Characteristic (ROC) curve was used to calculate the cutoff value. <h3>Results</h3> The mean G8 scores by age were 12.7 (range: 7-17) for ≤74 years, 12.9 (range: 7-17) for 75-79 years, and 10.4 (range: 4.5-15) for ≥80 years, and significantly lower scores for ≥80 years, but no significant difference between ≤74 and 75-79 years. There were 26 patients in the standard group, of which only one was ≥80 years. In the patients ≤79 years, the G8 score was significantly higher in the standard group (mean: 13.9 points in the standard group and 11.6 points in the non-standard group) (p<0.01), but age was not significantly different between the standard and non-standard groups (p=0.94). The cut-off value of the G8 score calculated by the ROC curve was 13 points. In patients ≥80 years, 10 patients received CRT (1 standard ChT, 9 reduced ChT), and 15 of 18 patients in the RT alone group received only local RT. In the patients ≥80 years, the G8 score was significantly higher in the CRT group (mean: 12.5 points in the CRT group and 9.2 points in the RT group) (p<0.01), but age was not significantly different between the CRT and RT groups (p=0.08). The cut-off value of the G8 score calculated by the ROC curve was 12 points. <h3>Conclusion</h3> Our results suggest that the G8 screening tool may be useful in determining the treatment strategy of definitive RT for esophageal cancer in the elderly. Future investigation of the relationship between the G8 score and treatment outcomes is required.

Integrating 18 F-FDG PET/CT with lung dose-volume for assessing lung inflammatory changes after arc-based radiotherapy for esophageal cancer: A pilot study.

The incidence of radiation pneumonitis (RP) has a highly linear relationship with low-dose lung volume. We previously established a volume-based algorithm (VBA) method to improve low-dose lung volume in radiotherapy (RT). This study assessed lung inflammatory changes by integrating fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-FDG PET/CT) with VBA for esophageal cancer patients undergoing arc-based RT. Thirty esophageal cancer patients received 18 F-FDG PET/CT imaging pre-RT and post-RT were included in a retrospective pilot study. We fused lung doses and parameters of PET/CT in RT planning. Based on VBA, we used the 5Gy isodose curve to define high-dose (HD) and low-dose (LD) regions in the lung volume. We divided patients into non-RP (nRP) and RP groups. The maximum, mean standardized uptake value (SUVmax, SUVmean), global lung glycolysis (GLG), mean lung dose (MLD) and V5-30 in lungs were analyzed. Area under the curve values were utilized to identify optimal cut-off values for RP. Eleven patients in the nRP group and 19 patients in the RP group were identified. In 30 RP lungs, post-RT SUVmax, SUVmean and GLG of HD regions showed significant increases compared to values for pre-RT lungs. There were no significant differences in values of 22 nRP lungs. Post-RT SUVmax and SUVmean of HD regions, MLD, and lung V5 and V10 in RP lungs were significantly higher than in nRP lungs. For detecting RP, the optimal cut-off values were post-RT SUVmax > 2.28 and lung V5 > 47.14%. This study successfully integrated 18 F-FDG PET/CT with VBA to assess RP in esophageal cancer patients undergoing RT. Post-RT SUVmax > 2.28 and lung V5 > 47.14% might be potential indicators of RP.

Assessment of photodynamic therapy as a salvage treatment for local failure after chemoradiotherapy or radiotherapy for esophageal cancer in patients aged 80 years or older.

ObjectivesChemoradiotherapy (CRT) or radiotherapy (RT) alone is often the treatment of choice for elderly patients with esophageal cancer with the expectation of organ preservation. However, salvage treatment remains a problem when endoscopic resection is not indicated for local failure after CRT/RT. Photodynamic therapy (PDT) is indicated for local failure after CRT/RT, but there are few reports on its efficacy and safety in elderly patients. This study aimed to assess the outcome of PDT for local failure after CRT/RT for esophageal cancer in elderly patients.MethodsThis retrospective single‐center study included 42 patients who first underwent PDT between April 2013 and June 2021. Patients aged ≥80 and <80 years were classified into the elderly and nonelderly groups, respectively. Local complete response rate, overall survival, progression‐free survival, and incidence of adverse events related to PDT were compared retrospectively between the groups.ResultsThe local complete response rate was 93.3% in the elderly group and 85.7 in the non‐elderly group. The 2‐year overall survival rate was 68.6% and 72.5%, and the 2‐year progression‐free survival rate was 49.5% and 70.0% in the elderly and nonelderly groups, respectively. There was no significant difference in any of these outcomes between the groups. In terms of adverse events, pneumonia and delirium tended to occur more frequently in the elderly group, but there were no serious adverse events in either group.ConclusionThe outcome of salvage PDT in the local control was comparable between the elderly and nonelderly patients for local failure after CRT/RT for esophageal cancer.

No survival benefit could be obtained from adjuvant radiotherapy in esophageal cancer treated with neoadjuvant chemotherapy followed by surgery: A SEER-based analysis.

BackgroundThe aim of this study is to assess the clinical benefit of postoperative radiotherapy (PORT) in patients with esophageal cancer (EC) who treated with neoadjuvant chemotherapy (NAC) and surgery via a national population-based database.MethodsPatients diagnosed with EC between 2004 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan–Meier survival analysis was used to compare the overall survival (OS) and cause-specific survival (CSS) difference between PORT vs. no-radiotherapy (RT) groups before and after propensity score matching (PSM). After PSM for baseline characteristics, Cox proportional hazard regression was performed to investigate the factors associated with OS.ResultsA total of 321 patients were included in the analysis. Of them, 91 patients (28%) received PORT. In the unmatched population, the no-RT group had improved OS compared with PORT (44 vs. 25 months, p = 0.002), and CSS was similar in patients undergoing NAC with or without PORT (42 vs. 71 months, p = 0.17). After PSM for baseline characteristics, the OS benefit of the no-RT group over the PORT group remained significant with a median OS of 46 vs. 27 months (p = 0.02), and CSS remained comparable between groups (83 vs. 81 months, p = 0.49). In subgroup analyses, PORT did not improve the OS among patients with adenocarcinoma in the subgroups of cN0, cN1, and cN2–3 (all p > 0.05). In Cox regression, aged ≥71 years old, cT3–4, cN2–3, and receiving PORT were independent predictors of worse OS, whereas cT4 and cN2–3 were independent predictors of worse CSS (all p < 0.05).ConclusionsThe present study demonstrated that no survival benefit could be obtained from the additional use of PORT after NAC and surgery in patients with EC. Well-designed prospective trials are needed to confirm our findings.

1251P CHARIOT: A phase I dose escalation study combining ATR inhibitor Berzosertib with chemoradiotherapy in oesophageal cancer using time to event continual reassessment (TiTE-CRM) method: Results from A1 cohort (combination with palliative RT)

Berzosertib (M6220) is a selective ATR protein kinase inhibitor. Preclinical studies in esophageal cancer cell lines show that combining M6220 with cisplatin increased tumour cell kill in vitro and caused tumour growth delay in combination with radiation in vivo. The A1 cohort of CHARIOT (NCT03641547) tested the feasibility of combining Berzosertib with radiation in esophageal cancer. Primary objective: establish recommended phase II dose (RP2D) in combination with palliative RT; secondary objectives: safety, toxicity and efficacy.