Phase 2 Study of Stereotactic Body Radiation Therapy for Patients with Oligometastatic Esophageal Squamous Cell Carcinoma

Radiotherapy combined with chemoimmunotherapy improves survival compared to chemoimmunotherapy alone as first-line treatment for oligometastatic esophageal squamous cell carcinoma

PURPOSE

To evaluate the safety and efficacy of radiotherapy combined with chemoimmunotherapy (RCIT) versus chemoimmunotherapy (CIT) alone as first-line treatment for oligometastatic esophageal squamous cell carcinoma (OESCC) at initial diagnosis.

METHODS

We retrospectively evaluated 140 patients newly diagnosed with OESCC who received RCIT or CIT as first-line treatment between June 2018 and December 2021. Among them, 76 patients were in the RCIT cohort and 64 patients in the CIT cohort. Propensity score matching (PSM) was used to simulate random allocation.

RESULTS

After 1:1 PSM, 61 well-paired patients were selected. The median follow-up duration was 34.7 months (95%CI: 30.6-38.8 months). After PSM, the median PFS for the RCIT and CIT groups was 10.9 (95%CI: 9.4-12.4) months and 7.3 (95%CI: 6.0-8.7) months, respectively (P = 0.004). The median OS for the RCIT and CIT groups was 22.4 (95%CI: 17.5-27.4) months and 13.4 (95%CI: 10.9-15.9) months, respectively (P = 0.031). There were significant differences in PFS (median PFS: 12.9 vs. 8.6 vs. 7.3 months, P = 0.003) between the group receiving radiotherapy (RT) for all lesions, the group receiving RT for partial lesions, and the CIT group, while OS was on the threshold of significance (median OS: 29.4 vs. 17.3 vs. 13.4 months, P = 0.052). No significant differences in the incidence of grade 3 or higher (G3+) treatment-related adverse events (TRAEs) were observed between the two groups. However, the incidence of G3+ pneumonitis (13.1% vs 1.6%, P = 0.038) were higher in the RCIT group compared to the CIT group.

CONCLUSION

RCIT as first-line treatment for OESCC was safe and efficacious. RCIT improved PFS/OS compared to CIT without increasing the overall high grade toxicity rate. However, the increased incidence of pneumonitis due to RT implementation cannot be disregarded.

Oligometastatic Esophagogastric Cancer: Does It Exist and How Do We Treat It?

PURPOSE OF THE REVIEW

This narrative review aims to provide an overview of recently completed randomized trials and expert consensus recommendations, and their implications for clinical practice and future trial design in patients with de-novo esophagogastric oligometastatic disease (OMD).

RECENT FINDINGS

The IKF-575/RENAISSANCE phase III trial showed no significant overall survival difference between systemic therapy alone and systemic therapy combined with local therapy for patients with gastric or gastroesophageal junction cancer and de-novo OMD, except for patients with retroperitoneal lymph node metastases only. The ESO-Shanghai 13 phase II trial demonstrated superiority of adding local therapy to systemic therapy for progression-free and overall survival in oligometastatic esophageal squamous cell carcinoma. The OMEC project developed a multidisciplinary European consensus for OMD, proposing a restrictive definition of OMD. Clinical trial assessing the optimal treatment of care are urgently needed. The findings highlight the importance of strict patient selection for local metastasis-directed treatment and the need for stratifying patients based on histology and location of metastases. Future research should focus on identifying biomarkers and clinical features to guide multidisciplinary treatment approaches for OMD.

Current status and perspectives of esophageal cancer: a comprehensive review

Esophageal cancer (EC) continues to be a significant global health concern, with two main subtypes: esophageal squamous cell carcinoma and esophageal adenocarcinoma. Prevention and changes in etiology, improvements in early detection, and refinements in the treatment have led to remarkable progress in the outcomes of EC patients in the past two decades. This seminar provides an in-depth analysis of advances in the epidemiology, disease biology, screening, diagnosis, and treatment landscape of esophageal cancer, focusing on the ongoing debate surrounding multimodality therapy. Despite significant advancements, EC remains a deadly disease, underscoring the need for continued research into early detection methods, understanding the molecular mechanisms, and developing effective treatments.

The value of intervention with radiotherapy after first-line chemo-immunotherapy in locally advanced or metastatic esophageal squamous cell carcinoma: A multi-center retrospective study

Background

Chemotherapy plus immunotherapy has become the standard first-line treatment of advanced or metastatic esophageal squamous cell carcinoma (ESCC), but median duration of response is only 7.0-8.3 months and progression-free survival (PFS, ∼6 months) is still far from satisfactory. We aim to evaluate whether early involvement of radiotherapy might improve the treatment outcome if objective response to first-line chemo-immunotherapy was observed in locally advanced or metastatic ESCC.

Methods

Patients were retrospectively collected from 3 institutions in China. Patients with histopathologically confirmed diagnoses of locally advanced or metastatic ESCC were identified, who objectively responded to first-line chemo-immunotherapy (complete or partial response, or stable disease) and also received radiotherapy of primary lesions with radiation dose of over 40 Gy, with or without radiotherapy of metastatic lesions before the first disease progression.

Results

A total of 72 eligible patients were identified. With median follow-up duration of 14.6 (range, 7.1-34.8) months, median progression-free survival (PFS) and overall survival (OS) were 13.5 (95 % CI,10.4-NA) months and 31.8 (95 % CI, 23.0-NA) months, respectively. Median duration from initiation of chemo-immunotherapy to radiotherapy was 2.9 (range, 0-15.1) months. Besides lower tumor burden as a significant factor of better treatment outcome, radiation dose ≥ 50 Gy was associated with superior PFS, while OS might be mainly related to tumor response to the induction chemo-immunotherapy. A low incidence of Grade 3 or above treatment-related adverse events were observed (19 %), and no treatment-related death occurred.

Conclusion

Our multi-center retrospective study showed survival benefit brought by early involvement of radiotherapy after first-line chemo-immunotherapy for patients with locally advanced or metastatic ESCC. However, further investigation is warranted in future prospective, controlled trials to assess the value of radio-immunotherapy in advanced or metastatic ESCC.

Toripalimab plus chemotherapy and radiotherapy for treatment-naive advanced esophageal squamous cell carcinoma: a single-arm phase 2 trial

This single-arm phase 2 trial (ChiCTR2100046715) examined previously untreated patients with advanced esophageal squamous cell carcinoma (ESCC) who received four cycles of paclitaxel with carboplatin every 3 weeks. Toripalimab was infused intravenously every 3 weeks for 12 months, or until disease progression or intolerable toxicity. Radiotherapy that encompassed the primary lesions and metastases commenced in the third cycle. The median progression-free survival time was 9.8 months (95% confidence interval [CI]: 6.8-not estimable) in the intent-to-treat population, failing to meet the pre-specified primary endpoints. Secondary endpoints included an objective response rate of 45.5%, a disease control rate of 57.6%, and a median duration of response of 11.5 months (interquartile range, 6.4-15.0). The 1-year progression-free survival and overall survival rates were 41.9% (95% CI: 27.7-63.5) and 69.7% (95% CI: 55.7-87.3), respectively. Lymphopenia was the most frequent grade ≥3 adverse event (82%), and an esophageal fistula developed in three patients (9.1%). No treatment-related deaths occurred. In prespecified exploratory biomarker analysis, higher densities of CD8 + T cells, CD11c+ dendritic cells, and CD68+ macrophages correlated with improved tumor response and prognosis. Radiotherapy supplementation to first-line chemo-immunotherapy for treatment-naive advanced ESCC demonstrated some antitumor activity and manageable safety profiles, warranting further randomized controlled trials.

Oligometastatic esophageal cancer cured by systemic therapy combined with radiotherapy to primary tumor and metastasis (metastasis-directed therapy)-small case series

The prognosis of metastatic esophageal cancer (EC) remains poor with an average life expectancy of around 9-12 months with standard systemic chemotherapy. The concept of oligometastatic disease (OMD) in EC cancer is controversial with no universally accepted definition. From the original cohort of metastatic oesophago-gastric (OG) cancer patients, 4 cases were identified that developed unusually favourable outcome with long-term survival and probable cure. In retrospect, all patients had OMD at presentation with striking similarities in terms of their clinical presentation, staging, treatment response and outcomes. All patients presented with locally advanced EC and 1-2 areas of metastatic disease (bone, lung, non-regional lymph node (LN) involvement). All were treated with combined therapeutic strategy using initial systemic chemotherapy followed by local radiotherapy to primary tumor and adjacent areas of visible/residual metastatic disease (metastasis-directed therapy). All patients experienced long-term survival (range = 7-13 years) with no evidence of recurrence and probable cure. The present case series adds to the growing pool of evidence indicating OM EC cancer represents a distinct and prognostically favorable subgroup.

European clinical practice guidelines for the definition, diagnosis, and treatment of oligometastatic esophagogastric cancer (OMEC-4)

INTRODUCTION

The OligoMetastatic Esophagogastric Cancer (OMEC) project aims to provide clinical practice guidelines for the definition, diagnosis, and treatment of esophagogastric oligometastatic disease (OMD).

METHODS

Guidelines were developed according to AGREE II and GRADE principles. Guidelines were based on a systematic review (OMEC-1), clinical case discussions (OMEC-2), and a Delphi consensus study (OMEC-3) by 49 European expert centers for esophagogastric cancer. OMEC identified patients for whom the term OMD is considered or could be considered. Disease-free interval (DFI) was defined as the time between primary tumor treatment and detection of OMD.

RESULTS

Moderate to high quality of evidence was found (i.e. 1 randomized and 4 non-randomized phase II trials) resulting in moderate recommendations. OMD is considered in esophagogastric cancer patients with 1 organ with ≤ 3 metastases or 1 involved extra-regional lymph node station. In addition, OMD continues to be considered in patients with OMD without progression in number of metastases after systemic therapy. 18F-FDG PET/CT imaging is recommended for baseline staging and for restaging after systemic therapy when local treatment is considered. For patients with synchronous OMD or metachronous OMD and a DFI ≤ 2 years, recommended treatment consists of systemic therapy followed by restaging to assess suitability for local treatment. For patients with metachronous OMD and DFI > 2 years, upfront local treatment is additionally recommended.

DISCUSSION

These multidisciplinary European clinical practice guidelines for the uniform definition, diagnosis and treatment of esophagogastric OMD can be used to standardize inclusion criteria in future clinical trials and to reduce variation in treatment.

Recurrence Pattern, Treatment Modalities, and Prognostic Factors After Definitive Chemoradiotherapy for Recurrent Esophageal Cancer

BACKGROUND

Recurrent esophageal cancer (EC) has a poor prognosis. However, the recurrence patterns and therapeutic outcomes after definitive chemoradiotherapy (CRT) are not fully understood. We analyzed survival and prognostic factors associated with post-definitive CRT recurrent EC.

METHODS

We retrospectively reviewed 71 consecutive patients with post-definitive CRT EC recurrence between 2008 and 2021 at our institution. Recurrence was locoregional, distant, and combined in 42 (59%), 18 (25%), and 11 (16%) patients, respectively. The median time from definitive CRT to recurrence was 8.3 months. Treatment modalities included local therapy, systemic therapy, and palliative care. Overall survival (OS) after recurrence was analyzed using the Kaplan-Meier and Cox proportional hazards models.

RESULTS

The median follow-up time from recurrence was 7.1 months, and the median survival time (MST) was 12.5 months. In the univariate analysis, longer time to recurrence, earlier stage at initial treatment, surgical tolerance at initial diagnosis, treatment modalities, and oligo-recurrence were associated with a better prognosis. The MST of the local therapy, systemic therapy, and palliative care groups were not reached, 11.8 months and 4.1 months, respectively (P < 0.001). In the multivariate analysis, treatment modalities and oligo-recurrence emerged as independent prognostic factors (P < 0.001 and P = 0.009).

CONCLUSIONS

Aggressive local therapy should be considered to improve the prognosis for patients with oligo-recurrence and/or indication of local therapy to treat recurrent EC.

Oligometastases of Esophageal Squamous Cell Carcinoma: A Review

Patients with oligometastases show distant relapse in only a limited number of regions. Local therapy such as surgical resection, radiotherapy, chemoradiotherapy, and radiofrequency ablation for the relapsed sites may thus improve patient survival. Oligometastases are divided into oligo-recurrence and sync-oligometastases. Oligo-recurrence indicates a primary lesion that is controlled, and sync-oligometastases indicate a primary lesion that is not controlled. The management of oligo-recurrence and sync-oligometastases in esophageal squamous cell carcinoma has not been clearly established, and treatment outcomes remain equivocal. We reviewed 14 articles, including three phase II trials, that were limited to squamous cell carcinoma. Multimodal treatment combining surgical resection and chemoradiotherapy for oligo-recurrence of esophageal squamous cell carcinoma appears to be a promising treatment. With the development of more effective chemotherapy and regimens that combine immune checkpoint inhibitors, it will become more likely that sync-oligometastases that were unresectable at the initial diagnosis can be brought to conversion surgery. Currently, a randomized, controlled phase III trial is being conducted in Japan to compare a strategy for performing definitive chemoradiotherapy and, if necessary, salvage surgery with a strategy for conversion surgery in patients who can be resected by induction chemotherapy.

Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

Systemic therapy with or without local intervention for oligometastatic oesophageal squamous cell carcinoma (ESO-Shanghai 13): an open-label, randomised, phase 2 trial

BACKGROUND

The efficacy of local therapy for patients with oligometastatic oesophageal squamous cell carcinoma is unclear. We aimed to assess the efficacy of local plus systemic therapy compared with systemic therapy alone in patients with oligometastatic oesophageal squamous cell carcinoma.

METHODS

The ESO-Shanghai 13 trial was a randomised, open-label, multicentre, phase 2 trial. Patients (aged ≥18 years) were recruited from six hospitals in China with histological confirmation of oligometastatic oesophageal squamous cell carcinoma with a controlled primary tumour and one to four metastatic lesions. Eligible patients were randomly assigned via a computer-generated schedule in a 1:1 ratio to receive either systemic therapy alone (ie, systemic therapy only group) or combined systemic and local therapy (ie, systemic and local therapy group). The systemic therapy regimens in both groups were at the discretion of the investigator and included chemotherapy alone, anti-PD-1 antibodies alone, or chemotherapy plus anti-PD-1 antibodies. Local therapy-radiotherapy, surgery, or thermal ablation-was delivered to all metastatic lesions for patients in the systemic and local therapy group. Randomisation was balanced dynamically on three factors: the number of disease sites, the lines of systemic therapy, and the location of the metastases. Patients and investigators were not masked to treatment allocation. The primary endpoint was progression-free survival, defined as the time from randomisation to progression or death from any cause in the intention-to-treat population. The safety population included all patients who had undergone random assignment and at least one of the intended therapies. This trial is registered with ClinicalTrials.gov, NCT03904927. The trial is ongoing but closed to new participants.

FINDINGS

116 patients were screened for enrolment between March 5, 2019, and Sept 16, 2021, and 104 patients who met the eligibility criteria were randomly assigned to the systemic and local therapy group (n=53) or the systemic therapy only group (n=51). 20 (38%) patients in the systemic plus local therapy group and 23 (45%) patients in the systemic therapy only group received anti-PD-1 antibody-based systemic therapy; three patients in the systemic and local therapy group did not receive systemic therapy. At a median follow-up of 30·5 months (IQR 24·7-37·8), median progression-free survival was 15·3 months (95% CI 10·1-20·5) in the systemic and local therapy group versus 6·4 months (5·2-7·6) in the systemic therapy only group (stratified hazard ratio 0·26 [95% CI 0·16-0·42]; stratified log rank p<0·0001). Grade 1-2 acute oesophagitis was more common in the systemic and local therapy group than in the systemic therapy only group (10 [19%] vs one [2%] patients; p=0·036). The number of patients who had grade 3 or worse treatment-related adverse events was similar between groups (25 [47%] vs 21 [41%]; p=0·538), with the most common adverse events being leukocytopenia (17 [32%] vs 18 [35%]) and neutropenia (19 [36%] vs 20 [39%]). Treatment-related deaths occurred in two patients in the systemic and local therapy group and one patient in the systemic therapy only group.

INTERPRETATION

The addition of local treatment for metastases could significantly improve progression-free survival among patients with oligometastatic oesophageal squamous cell carcinoma being treated with systemic therapy. Our findings suggest that combining local and systemic therapy could be a treatment option for patients with oligometastatic oesophageal squamous cell carcinoma, but further support from phase 3 trials is required.

FUNDING

Science and Technology Commission of Shanghai Municipality, National Nature Science Foundation of China, and Shanghai Municipal Health Commission.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Radiotherapy for Advanced Esophageal Cancer: from Palliation to Curation

OPINION STATEMENT

Esophageal cancer is a global health problem, which is 7th most common and 6th most deadly cancer. It has been the era of immuno-oncology for esophageal cancer management. Radiation therapy has been one of the key local therapeutic approaches for esophageal cancer treatment, while its role in advanced disease is challenging and debatable. There have been emerging clinical and translational studies of radiation therapy in recurrent or metastatic esophageal cancer. Immunotherapy has been established the standard care of 1st and 2nd line systemic therapies of advanced esophageal cancer, and the development of tumor immunity has opened a new chapter for the esophageal cancer radiation therapy. The current review will summarize the classic radiation therapy research in advanced esophageal cancer, as well as the most recent key findings. The subtitles will cover palliative radiotherapy for dysphagia, re-radiation for recurrent disease, oligo-focal disease management and stereotactic radiation therapy, and radiotherapy with immunotherapy. Radiotherapy plays vital role in multidisciplinary management of advanced EC. External or intratumoral irradiation has been used for palliation of dysphagia and improving QOL in esophageal cancer patients traditionally, while recent clinical and technical advance enables radiotherapy to be considered in recurrent or metastatic disease for curation attention. Novel clinical and translational investigation is opening a new chapter of radiotherapy with immunotherapy for benefiting advanced EC patients.

Combine radiotherapy and immunotherapy in esophageal squamous cell carcinoma

Immune checkpoint inhibitors(ICIs) have improved the survival of advanced esophageal squamous cell carcinoma (ESCC) patients. Radiotherapy is one of the common therapies to treat esophageal cancer. However, whether combination radiation therapy can increase the efficacy of immunotherapy is still up for debate. Radiotherapy combined with immunotherapy has proven to be a reliable and effective treatment for tumors, and it can work in combination with immunotherapy to achieve better anti-tumor effects. This review aims to discuss the efficacy and safety of combining radiotherapy and immunotherapy to treat ESCC by stages as well as the optimum radiotherapy dose and target volume, with a summary of clinical trials in ESCC.

Radiotherapy combined with immune checkpoint inhibitors in locally advanced/metastatic esophageal squamous cell carcinoma: clinical trials, efficacy and future directions

Esophageal squamous cell carcinoma (ESCC) is a common malignancy worldwide and often diagnosed at advanced stages with poor prognosis. Combination of radiotherapy and immunotherapy seems to be a promising approach for treating ESCC. This comprehensive review article summarizes the current state of combination of radiotherapy and immunotherapy in locally advanced/metastatic ESCC, delineates the clinical trials that merit attention, and outlines unresolved issues and future research directions in this field. The clinical trial findings suggest that radio-immunotherapy combination may improve tumor response and overall survival with manageable side effects, highlighting the importance of patient selection and the necessity for further research to optimize treatment strategies. Issues such as irradiation dosage, fractionation regimen, irradiation site and technique of radiotherapy, as well as the timing, sequence and duration of combination therapy will all affect treatment outcomes, justifying further in-depth investigation.

Outcomes of solitary postoperative recurrence of esophageal squamous cell carcinoma diagnosed with FDG-PET/CT and treated with definitive radiation therapy

BACKGROUND

Surgical resection of esophageal cancer is frequently performed to achieve a complete cure. However, the postoperative recurrence rate is 36.8-42.5%, leading to poor prognosis. Radiation therapy has been used to treat recurrences; solitary recurrence has been proposed as a prognostic factor for radiation therapy, though its significance is unclear. ¹⁸F-fluorodeoxyglucose positron emission tomography is a highly accurate diagnostic modality for esophageal cancer. This retrospective study aimed to analyze the outcomes of solitary postoperative recurrences of esophageal squamous cell carcinoma diagnosed with ¹⁸F-fluorodeoxyglucose positron emission tomography and treated with definitive radiation therapy.

METHODS

We examined 27 patients who underwent definitive radiation therapy for single or multiple postoperative recurrences of esophageal squamous cell carcinoma between May 2015 and April 2021. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography was performed within 3 months before the commencement of radiation therapy. Kaplan-Meier, univariate, and multivariate analyses were performed to examine the overall survival and identify potential prognostic factors.

RESULTS

The 1-, 2-, and 3-year overall survival rates were 85.2%, 62.6%, and 47.3%, respectively, and solitary recurrence was the only significant factor associated with overall survival (P = 0.003). The 1-, 2-, and 3-year overall survival rates in patients with solitary recurrence were 91.7%, 80.2%, and 80.2%, respectively, and in patients with multiple recurrences they were 80.0%, 50.3%, and 25.1%, respectively. Multivariate analysis also showed solitary recurrence as a significant factor for overall survival.

CONCLUSIONS

When diagnosed with ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography, solitary recurrence appears to have a more favorable prognosis than multiple recurrences.

Stereotactic radiation therapy for oligometastatic esophagogastric adenocarcinoma: outcome and prognostic factors

OBJECTIVE

The aim of this study was to evaluate clinical results and prognostic factors in a cohort of patient with oligometastatic esophagogastric adenocarcinoma treated with stereotactic radiation therapy (SRT).

METHODS

This retrospective study included patients affected by 1-3 metastases treated with SRT from 2013 to 2021. Local control (LC), overall survival (OS), progression-free survival (PFS), time to polymetastatic dissemination (TTPD) and time to systemic therapy change/initiation (TTS) were evaluated.

RESULTS

Between 2013 and 2021, 55 patients were treated with SRT on 80 oligometastatic sites. Median follow-up was 20 months. Nine patients had local progression. 1 and 3 years LC was respectively 92 and 78%. 41 patients experienced further distant disease progression, median PFS was 9.6 months, 1 and 3 years PFS was respectively 40 and 15%. 34 patients died, median OS was 26.6 months, 1 and 3 years OS was respectively 78 and 40%. During follow-up, 24 patients changed or initiated a new systemic therapy; median TTS time was 9 months. 27 patients experienced poliprogression, 44% after 1 year and 52% after 3 years. Median TTPD was 8 months. The best local response (LR), tyming of metastases and PS were related with prolonged PFS on multivariate analysis. LR was correlated with OS at multivariate analysis.

CONCLUSION

SRT represents a valid treatment for oligometastatic esophagogastric adenocarcinoma. CR correlated with PFS and OS, while metachronous metastasis and a good PS correlated with a better PFS.

ADVANCES IN KNOWLEDGE

In selected gastroesopagheal oligometastatic patients, SRT can prolong OS Local response to SRT, metachronous timing of metastases and better PS improve PFS.Local response correlates with OS.

Safety and Efficacy of Concurrent or Sequential Radiotherapy Plus (PD-1) Inhibitors in Oligometastatic Esophageal Cancer

Purpose

We assess real-world outcomes, including safety and efficacy, of concurrent or sequential treatment with radiotherapy plus programmed cell death protein 1 (PD-1) inhibitors in patients with oligometastatic esophageal cancer (OMEC).

Methods

This cohort study retrospectively collected clinical data of patients with synchronous or metachronous OMEC. All patients underwent concurrent or sequential treatment with radiotherapy plus PD-1 inhibitors. Each patient had up to five measurable metastatic lesions and up to three organs involved. Study endpoints were progression-free survival (PFS), treatment-related toxicities, locoregional progression-free survival (LRPFS), objective response rate (ORR), and disease control rate (DCR). Description statistics and Kaplan-Meier models were used for statistical analysis.

Results

A total of 86 patients were included, most of whom were diagnosed with squamous cell carcinoma histology (98%) and presented with synchronous OMEC (64%). The median follow-up period was 17 months (range: 6-32 months), the median PFS was 15.2 months (95% confidence interval: 12.1-18.2 months); and the 1- and 2-year PFS rates were 61.4% and 26.7%, respectively. The 1- and 2-year LRPFS were 91.3% and 57.3%, respectively. The ORR and DCR were 46.5% and 91.8%, respectively. Forty-two patients (48.8%) experienced grade 3 or higher treatment-related adverse events (TRAEs); a grade 5 treatment-related adverse event was observed in one patient (1.2%) who died of immune-related pneumonitis.

Conclusion

Combining radiotherapy with PD-1 inhibitors is a safe and effective treatment option for patients with OMEC. No new safety concerns were identified in this study. However, due to the potential risk of cumulative toxicity, an individual risk-benefit assessment for each patient is required prior to treatment initiation.

Study protocol for the OligoMetastatic Esophagogastric Cancer (OMEC) project: A multidisciplinary European consensus project on the definition and treatment for oligometastatic esophagogastric cancer

BACKGROUND

A uniform definition and treatment for oligometastatic esophagogastric cancer is currently lacking. However, a comprehensive definition of oligometastatic esophagogastric cancer is necessary to initiate studies on local treatment strategies (e.g. metastasectomy or stereotactic radiotherapy) and new systemic therapy agents in this group of patients. For this purpose, the OligoMetastatic Esophagogastric Cancer (OMEC) project was established. The OMEC-project aims to develop a multidisciplinary European consensus statement on the definition, diagnosis, and treatment for oligometastatic esophagogastric cancer and provide a framework for prospective studies to improve outcomes of these patients.

METHODS

The OMEC-project consists of five studies, including 1) a systematic review on definitions and outcomes of oligometastatic esophagogastric cancer; 2) real-life clinical scenario discussions in multidisciplinary expert teams to determine the variation in the definition and treatment strategies; 3) Delphi consensus process through a starting meeting, two Delphi questionnaire rounds, and a consensus meeting; 4) publication of a multidisciplinary European consensus statement; and 5) a prospective clinical trial in patients with oligometastatic esophagogastric cancer.

DISCUSSION

The OMEC project aims to establish a multidisciplinary European consensus statement for oligometastatic esophagogastric cancer and aims to initiate a prospective clinical trial to improve outcomes for these patients. Recommendations from OMEC can be used to update the relevant guidelines on treatment for patients with (oligometastatic) esophagogastric cancer.

Perspectives on the Management of Oligometastatic Disease in Esophago-Gastric Cancer

Gastric adenocarcinoma and esophageal cancer are the fifth and seventh most common cancer types worldwide. At the time of initial diagnosis, up to 50% of esophagogastric cancers present with distant metastatic lesions and are candidates for chemotherapy. Curative surgery in this stage is still an experimental approach. Only a small number of these metastatic patients show an oligometastatic disease with no uniform definition of what oligometastatic means in gastric cancer. Nevertheless, the question remains unanswered as to whether these patients are still candidates for curative concepts. Some studies have attempted to answer this question but have not been adequately designed to address the role of a curative-intended multimodal therapy in this setting. The current FLOT-5 is designed to potentially provide a definitive answer to the question of whether curatively intended surgery plays a role or is a disadvantage in this setting.

Stereotactic radiotherapy or metastasectomy for oligometastatic esophagogastric cancer: a nationwide population-based cohort study

•

This nationwide study included patients with esophagogastric cancer and OMD.

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Local treatment of OMD was associated with improved OS.

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Local treatment of OMD plus systemic therapy was associated with better OS.

•

Randomized trials are warranted to conform results.

Background and purpose

This nationwide population-based study analyzed the outcomes of local treatment (i.e. stereotactic body radiotherapy [SBRT] or metastasectomy) or systemic therapy for oligometastatic disease (OMD) in patients with esophagogastric cancer in The Netherlands.

Materials and methods

Between 2015 and 2016, all patients in The Netherlands with esophagogastric cancer and synchronous or metachronous OMD were eligible for inclusion. Patients who underwent local treatment of OMD (SBRT or metastasectomy) and/or systemic therapy were included. OMD was defined as distant metastases in 1 organ or 1 extra-regional lymph node region. The primary outcomes were overall survival (OS) and independent prognostic factors for OS. OS was calculated from diagnosis of OMD. Prognostic factors for OS were analyzed using a multivariable Cox proportional hazard model.

Results

A total of 594 patients were included, of whom 83 underwent local treatment for OMD alone, 22 local treatment plus systemic therapy, and 489 systemic therapy alone. Median OS after local treatment for OMD alone was 16.0 months, local treatment plus systemic therapy 22.7 months, and after systemic therapy alone 8.5 months. Improved OS was independently associated with local treatment for OMD alone or combined with systemic therapy as compared with systemic therapy alone (hazard ratio [HR] 0.52, 95% CI: 0.31–0.90 and HR 0.42, 95% CI: 0.22-0.82, respectively) and a controlled primary tumor(HR 0.48, 95% CI: 0.27–0.86). Worse OS was independently associated with worse performance scores (HR 1.41, 95%: 1.32-1.75), poorly or undiffertumor as compared with good or moderadifferentiated tumor (HR 1.37, 95% CI: 1.06-1.76), and peritoneal as compared with lymph mode metastases (HR 1.39, 95% CI: 1.00-1.93).

Conclusion

Local treatment of OMD alone or combined with systemic therapy was independently associated with improved OS as compared with systemic therapy alone in this population-based cohort study in The Netherlands. Randomized controlled trials are warranted to confirm these results.

Incidence and survival of patients with oligometastatic esophagogastric cancer: a multicenter cohort study

PURPOSE /OBJECTIVE

This multicenter study assessed the incidence and survival of patients with esophagogastric cancer and oligometastatic disease (OMD) in two tertiary referral cancer centers in The Netherlands and Switzerland.

MATERIALS /METHODS

Between 2010-2021, patients with metastatic esophagogastric cancer were identified. Patients with de-novo OMD were included (first-time diagnosis of ≤5 distant metastases on ¹⁸F-FDG-PET/CT). Control of the primary tumor was considered in patients who underwent primary tumor resection or definitive chemoradiotherapy without locoregional recurrence. Treatment of OMD was categorized into 1) systemic therapy, 2) local treatment (stereotactic body radiotherapy or metastasectomy), 3) local plus systemic therapy, or 4) best supportive care. The primary outcomes were overall survival (OS) and independent prognostic factors for OS. Independent prognostic factors for OS were analyzed using multivariable Cox proportional hazard models.

RESULTS

In total, 830 patients with metastatic esophagogastric cancer were identified of whom 200 patients with de-novo OMD were included (24%). The majority of included patients had esophageal cancer (73%) with adenocarcinoma histology (79%) and metachronous OMD (52%). The primary tumor was controlled in 68%. Treatment of OMD was systemic therapy (25%), local treatment (43%), local plus systemic therapy (13%), or best supportive care (18%). Median follow-up was 14 months (interquartile range: 7-27). Median OS was 16 months (95% CI: 13-21). Improved OS was independently associated with local plus systemic therapy compared with systemic therapy alone (hazard ratio [HR] 0.47, 95% confidence interval [CI]: 0.25-0.87). Worse OS was independently associated with squamous cell carcinoma (HR 1.70, 95% CI: 1.07-2.74), bone oligometastases (HR 2.44, 95% CI: 1.28-4.68), brain oligometastases (HR 1.98, 95% CI: 1.05-4.69), and two metastatic locations (HR 2.07, 95% CI: 1.04-4.12). Median OS after local plus systemic therapy was 35 months (95% CI: 22-NA) as compared with 13 months (95% CI: 9-21, p<0.001) after systemic therapy alone for OMD.

CONCLUSION

Patients with metastatic esophagogastric cancer present in 25% with de-novo OMD. Local treatment of OMD plus systemic therapy was independently associated with long-term OS and independently improved OS when compared with systemic therapy alone. Randomized controlled trials are warranted to confirm these results.

Survival impact of concurrent chemoradiotherapy for elderly patients with synchronous oligometastatic esophageal squamous cell carcinoma: A propensity score matching and landmark analyses

PURPOSE

To evaluate the potential benefits of concurrent chemoradiotherapy (CCRT), and to establish a nomogram for predicting survival outcomes of elderly patients with synchronous oligometastatic esophageal squamous cell carcinoma (SOEC).

MATERIALS AND METHODS

This study eventually enrolled 314 elderly patients who initially diagnosed with SOEC from two centers. Treatment responses and outcomes of 151 patients receiving CCRT and 163 patients undergoing chemotherapy alone (CT) were compared. Propensity score matching and landmark analyses were performed to control potential confounding factors. A nomogram was established on the basis of the Cox regression model.

RESULTS

After a median follow-up of 42.3 months, CCRT was superior to CT alone in objective response rate (ORR, 59.6% vs. 39.9%, P < 0.001), median progression-free survival (PFS, 10.0 vs. 7.2 months, P < 0.001), and median overall survival (OS, 18.5 vs. 15.6 months, P < 0.001). The propensity score matching (PSM) and landmark analyses redemonstrated the same trend (P < 0.01). On hierarchical analysis, patients with 1-3 metastatic lesions involving one organ displayed longer median PFS (9.0 vs. 7.8 months, P = 0.008) and OS (17.8 vs. 15.2 months, P < 0.001) than those with 4-5 metastatic lesions involving 2-3 organs. The major toxicities of grade III or higher for CCRT included leukocytopenia (23.2%), radiation esophagitis (7.3%), and radiation pneumonitis (8.6%). Cox multivariate analysis showed that the number of metastatic lesions (P = 0.012) and tumor response (P < 0.001) were independent prognostic factors associated with OS. A nomogram was established by incorporating the number of metastatic lesions and tumor response, with a concordance index of 0.743 after internal cross-validation. Calibration curves and decision curve analysis confirmed that nomogram had a favorable predictive value for individualized survival.

CONCLUSIONS

Compared with CT alone, CCRT exhibited superior efficacy and acceptable toxicity in the first-line treatment for elderly patients with SOEC. The current study supports the oligometastatic definition of ≤3 metastatic lesions involving one organ for esophageal cancer patients. The constructed nomogram can effectively predict the individualized survival.

Innovation, value and reimbursement in radiation and complex surgical oncology: Time to rethink

BACKGROUND AND PURPOSE

Complex surgery and radiotherapy are the central pillars of loco-regional oncology treatment. This paper describes the reimbursement schemes used in radiation and complex surgical oncology, reports on literature and policy reviews.

MATERIAL AND METHODS

A systematic review of the literature of the reimbursement models has been carried out separately for radiotherapy and complex cancer surgery based on PRISMA guidelines. Using searches of PubMed and grey literature, we identified articles from scientific journals and reports published since 2000 on provider payment or reimbursement systems currently used in radiation oncology and complex cancer surgery, also including policy models.

RESULTS

Most European health systems reimburse radiotherapy using a budget-based, fee-for-service or fraction-based system; while few reimburse services according to an episode-based model. Also, the reimbursement models for cancer surgery are mostly restricted to differences embedded in the DRG system and adjustments applied to the fees, based on the complexity of each surgical procedure. There is an enormous variability in reimbursement across countries, resulting in different incentives and different amounts paid for the same therapeutic strategy.

CONCLUSION

A reimbursement policy, based on the episode of care as the basic payment unit, is advocated for. Innovation should be tackled in a two-tier approach: one defining the common criteria for reimbursement of proven evidence-based interventions; another for financing emerging innovation with uncertain definitive value. Relevant clinical and economic data, also collected real-life, should support reimbursement systems that mirror the actual cost of evidence-based practice.

Innovation, value and reimbursement in radiation and complex surgical oncology: time to rethink

BACKGROUND AND PURPOSE

Complex surgery and radiotherapy are the central pillars of loco-regional oncology treatment. This paper describes the reimbursement schemes used in radiation and complex surgical oncology, reports on literature and policy reviews.

MATERIAL AND METHODS

A systematic review of the literature of the reimbursement models has been carried out separately for radiotherapy and complex cancer surgery based on PRISMA guidelines. Using searches of PubMed and grey literature, we identified articles from scientific journals and reports published since 2000 on provider payment or reimbursement systems currently used in radiation oncology and complex cancer surgery, also including policy models.

RESULTS

Most European health systems reimburse radiotherapy using a budget-based, fee-for-service or fraction-based system; while few reimburse services according to an episode-based model. Also, the reimbursement models for cancer surgery are mostly restricted to differences embedded in the DRG system and adjustments applied to the fees, based on the complexity of each surgical procedure. There is an enormous variability in reimbursement across countries, resulting in different incentives and different amounts paid for the same therapeutic strategy.

CONCLUSION

A reimbursement policy, based on the episode of care as the basic payment unit, is advocated for. Innovation should be tackled in a two-tier approach: one defining the common criteria for reimbursement of proven evidence-based interventions; another for financing emerging innovation with uncertain definitive value. Relevant clinical and economic data, also collected real-life, should support reimbursement systems that mirror the actual cost of evidence-based practice.

Lung Stereotactic Body Radiotherapy (SBRT) Using Spot-Scanning Proton Arc (SPArc) Therapy: A Feasibility Study

Purpose

We developed a 4D interplay effect model to quantitatively evaluate breathing-induced interplay effects and assess the feasibility of utilizing spot-scanning proton arc (SPArc) therapy for hypo-fractionated lung stereotactic body radiotherapy (SBRT). The model was then validated by retrospective application to clinical cases.

Materials and Methods

A digital lung 4DCT phantoms was used to mimic targets in diameter of 3cm with breathing motion amplitudes: 5, 10, 15, and 20 mm, respectively. Two planning groups based on robust optimization were generated: (1) Two-field Intensity Modulated Proton Therapy (IMPT) plans and (2) SPArc plans via a partial arc. 5,000 cGy relative biological effectiveness (RBE) was prescribed to the internal target volume (ITV) in five fractions. To quantitatively assess the breathing induced interplay effect, the 4D dynamic dose was calculated by synchronizing the breathing pattern with the simulated proton machine delivery sequence, including IMPT, Volumetric repainting (IMPT_volumetric), iso-layered repainting (IMPT_layer) and SPArc. Ten lung patients’ 4DCT previously treated with VMAT SBRT, were used to validate the digital lung tumor model. Normal tissue complicated probability (NTCP) of chestwall toxicity was calculated.

Result

Target dose were degraded as the tumor motion amplitude increased. The 4D interplay effect phantom model indicated that motion mitigation effectiveness using SPArc was about five times of IMPT_volumetric or IMPT_layer using maximum MU/spot as 0.5 MU at 20 mm motion amplitude. The retrospective study showed that SPArc has an advantage in normal tissue sparing. The probability of chestwall’s toxicity were significantly improved from 40.2 ± 29.0% (VMAT) (p = 0.01) and 16.3 ± 12.0% (IMPT) (p = 0.01) to 10.1 ± 5.4% (SPArc). SPArc could play a significant role in the interplay effect mitigation with breathing-induced motion more than 20 mm, where the target D99 of 4D dynamic dose for patient #10 was improved from 4,514 ± 138 cGy [RBE] (IMPT) vs. 4,755 ± 129 cGy [RBE] (SPArc) (p = 0.01).

Conclusion

SPArc effectively mitigated the interplay effect for proton lung SBRT compared to IMPT with repainting and was associated with normal tissue sparing. This technology may make delivery of proton SBRT more technically feasible and less complex with fewer concerns over underdosing the target compared to other proton therapy techniques.

Local therapy for oligometastatic esophageal squamous cell carcinoma: a prospective, randomized, Phase II clinical trial

For patients with oligometastatic esophageal squamous cell carcinoma, the efficacy of local therapy is still controversial because of patient selection and lack of adequate controls in most studies. Here the authors design the ESO-Shanghai 13 trial, a prospective, multicenter, randomized, Phase II trial, to assess the impact of combined local therapy and systemic therapy on progression and survival compared with systemic therapy alone for patients with four or less metastases. A total of 102 patients will be recruited over 3 years from approximately five centers and randomized in a 1:1 ratio to receive either systemic therapy alone or systemic therapy and local therapy, such as radiation, surgery and thermal ablation. The primary endpoint is progression-free survival. The secondary endpoints are overall survival, local control, toxicity and quality of life. Clinical trial registration: NCT03904927 (ClinicalTrials.gov).