A large pooled analysis of liver oligometastases, classified accordingly to the ESTRO/EORTC recommendations, treated by stereotactic radiotherapy (SBRT) and Radiosurgery (SRS) was carried out. The clinical and dosimetric data of patients who underwent SBRT/SRS for liver metastases were analysed in terms of efficacy and toxicity profile. In particular, the Local Control (LC), the Distant Metastases Free Survival (DMFS), the Disease-Free Survival (DFS), the Overall Survival (OS), and the Next Systemic Therapy Free Survival (NEST-FS) rates were analysed. 113 patients (M/F: 49/64), accounting for a total of 150 hepatic lesions (March 2006-February 2023) in two Italian radiotherapy Institutions were evaluated. Median age was 67 years old (36-92) and 48 (42.5%) patients had at least one comorbidity. The majority of the lesions were induced (30.7%) or repeated oligoprogressive (12.7%) metastases. 98 lesions were treated with more than one daily fraction (mainly 50 Gy in 5 fractions), while 52 were radiosurgery treatments (mainly 32 Gy). The treatment response at 3-4 months was evaluable in 147 lesions: complete response was 32.0%, partial response 17.0%, and stable disease 32.0%. Actuarial LC, DMFS, DFS, OS, and NEST-FS at 1 year were 75.8%, 37.7%, 34.9%, 78.7%, and 59.4% respectively; while actuarial LC, DMFS, DFS, OS, and NEST-FS at 2 years were 52.1%, 24.9%, 21.9%, 51.3%, and 36.8%, respectively. The achievement of complete response, synchronous oligometastases, and no treatment interruptions correlated with a more favorable outcomes. As per the toxicity profile, we registered only two acute and one late toxicity cases higher than grade 2. Stereotactic treatment for liver metastases seems to be a safe and promising option in terms of local control. The best results in term of outcomes have been obtained in patients with complete response, synchronous oligometastases, favorable histology, and no treatment interruptions.

BACKGROUND: 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.
CONCLUSIONS: 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.

BACKGROUND: Small retrospective series suggest that local consolidative treatment (LCT) may improve survival in oligometastatic pancreatic ductal adenocarcinoma (PDAC). However, no uniform definition of oligometastatic disease (OMD) in PDAC exists; this impedes meaningful conclusions.
METHODS: A systematic literature search using PubMed, Web of Science, and Cochrane CENTRAL registries for studies and protocols reporting on definitions and/or LCT of OMD in PDAC was performed. The primary endpoint was the definition of OMD. Levels of agreement were categorized as consensus (≥75% agreement between studies), fair agreement (50%-74%), and absent/poor agreement (<50%).
RESULTS: After screening of 5374 abstracts, the full text of 218 studies was assessed, of which 76 were included in the qualitative synthesis. The majority of studies were retrospective (n = 66, 87%), two were prospective studies and eight were study protocols. Studies investigated mostly liver (n = 38, 51%) and lung metastases (n = 15, 20%). Across studies, less than one-half (n = 32, 42%) reported a definition of OMD, while 44 (58%) did not. Involvement was limited to a single organ (consensus). Additional criteria for defining OMD were the number of lesions (consensus), metastatic site (poor agreement), metastatic size (poor agreement), treatment possibilities (poor agreement), and biomarker response (poor agreement). Liver OMD could involve three or fewer lesions (consensus) and synchronous disease (fair agreement), while lung metastases could involve two or fewer lesions and metachronous disease (consensus). The large majority of studies were at a high risk of bias or did not include any control groups.
CONCLUSIONS: Definitions of OMD were not used or varied widely between studies hampering across-study comparability and highlighting an unmet need for a consensus. The present study is part of a multistep process that aims to develop an interdisciplinary consensus on OMD in pancreatic cancer.

The oligometastatic state in non-small cell lung cancer (NSCLC) has recently become well-established. However, the specific definition of oligometastases remains unclear. Several smaller randomized studies have investigated the safety and efficacy of radiation as metastasis-directed therapy (MDT) in oligometastatic NSCLC, which have led the way to larger studies currently accruing patients globally.
This review covers the definitions of \'oligometastases\' and explains why the oligometastatic state is becoming increasingly relevant in metastatic NSCLC. This includes the rationale for MDT in oligometastatic NSCLC, specifically reviewing stereotactic body radiation therapy (SBRT) as a treatment strategy. This review details many randomized trials that support radiation as MDT and introduces trials that are currently accruing patients. Finally, it explores some of the controversies that warrant further investigation.
Radiation treatment, specifically SBRT, has been shown to be safe, convenient, and cost-effective as MDT. As systemic therapy, including targeted agents and immunotherapy, continues to improve, the precise role(s) and timing of radiation therapy may evolve. However, radiation therapy as MDT will continue to be an integral part of treatment in patients with oligometastatic NSCLC.

OBJECTIVE: A systematic review of treatment characteristics, outcomes, and treatment-related toxicities of stereotactic body radiation therapy (SBRT) for pulmonary oligometastases served as the basis for development of this International Stereotactic Radiosurgery Society (ISRS) practice guideline.
METHODS: In accordance with PRISMA guidelines, a systematic review was performed of retrospective series with ≥50 patients/lung metastases, prospective trials with ≥25 patients/lung metastases, analyses of specific high-risk situations, and all randomized trials published between 2012 and July 2022 in the MEDLINE or Embase database using the key words \"lung oligometastases\", \"lung metastases\", \"pulmonary metastases\", \"pulmonary oligometastases\", \"stereotactic body radiation therapy (SBRT)\" and \"stereotactic ablative body radiotherapy (SBRT)\". Weighted random effects models were used to calculate pooled outcomes estimates.
RESULTS: Of the 1884 articles screened, 35 analyses (27 retrospective-, 5 prospective, and 3 randomized trials) reporting on treatment of >3600 patients and >4650 metastases were included. The median local control was 90 % (Range: 57-100 %) at 1 year and 79 % (R: 70-96 %) at 5 years. Acute toxicity ≥3 was reported for 0.5 % and late toxicity ≥3 for 1.8 % of patients. A total of 21 practice recommendations covering the areas of staging & patient selection (n = 10), SBRT treatment (n = 10), and follow-up (n = 1) were developed, with agreements rates of 100 %, except for recommendation 13 (83 %).
CONCLUSIONS: SBRT represents an effective definitive local treatment modality combining high local control rates with low risk of radiation-induced toxicities.

Local treatment improves the outcomes for oligometastatic disease (OMD, i.e. an intermediate state between locoregional and widespread disseminated disease). However, consensus about the definition, diagnosis and treatment of oligometastatic oesophagogastric cancer is lacking. The aim of this study was to develop a multidisciplinary European consensus statement on the definition, diagnosis and treatment of oligometastatic oesophagogastric cancer.
In total, 65 specialists in the multidisciplinary treatment for oesophagogastric cancer from 49 expert centres across 16 European countries were requested to participate in this Delphi study. The consensus finding process consisted of a starting meeting, 2 online Delphi questionnaire rounds and an online consensus meeting. Input for Delphi questionnaires consisted of (1) a systematic review on definitions of oligometastatic oesophagogastric cancer and (2) a discussion of real-life clinical cases by multidisciplinary teams. Experts were asked to score each statement on a 5-point Likert scale. The agreement was scored to be either absent/poor (<50%), fair (50%-75%) or consensus (≥75%).
A total of 48 experts participated in the starting meeting, both Delphi rounds, and the consensus meeting (overall response rate: 71%). OMD was considered in patients with metastatic oesophagogastric cancer limited to 1 organ with ≤3 metastases or 1 extra-regional lymph node station (consensus). In addition, OMD was considered in patients without progression at restaging after systemic therapy (consensus). For patients with synchronous or metachronous OMD with a disease-free interval ≤2 years, systemic therapy followed by restaging to consider local treatment was considered as treatment (consensus). For metachronous OMD with a disease-free interval >2 years, either upfront local treatment or systemic treatment followed by restaging was considered as treatment (fair agreement).
The OMEC project has resulted in a multidisciplinary European consensus statement for the definition, diagnosis and treatment of oligometastatic oesophagogastric adenocarcinoma and squamous cell cancer. This can be used to standardise inclusion criteria for future clinical trials.

BACKGROUND: The European Society of Medical Oncology (ESMO) recently published extensively revised guidelines on cancer of unknown primary (CUP). The new version contains the following relevant amendments: with respect to diagnostics of CUP, the current guidelines aim for a more precise and standardized definition of CUP by establishing diagnostic algorithms. Recommendations for molecular diagnostics of cancer tissue have also been implemented. With respect to CUP classification, the favorable category has been revised. A carcinoma with immunohistochemistry typical for renal cell carcinoma (renal-like CUP) was introduced in the new definition of favorable subtypes, for which a specific treatment is indicated. Based on a newly defined oligometastatic situation a subgroup with localized cancer potentially curatively treatable with surgery and/or radiotherapy was introduced into the CUP classification. With respect to treatment of CUP, the current guidelines present options beyond empirical chemotherapy, which is still the standard of care treatment, and pinpoint indications and predictive biomarkers for targeted and immune checkpoint inhibitor treatment.
UNASSIGNED: The European Society of Medical Oncology (ESMO) recently published extensively revised guidelines on the CUP syndrome. The new version contains the following relevant amendments: the current guidelines aim for a more precise and standardized definition of CUP by establishing diagnostic algorithms with respect to the diagnostics of CUP syndrome. Recommendations for molecular diagnostics of cancer tissue have also been implemented. The classification of the CUP syndrome has also been revised. A carcinoma with immunohistochemistry typical for renal cell carcinoma (renal-like CUP) was introduced in the new definition of favorable subtypes, for which a specific treatment is indicated. Based on a newly defined oligometastatic situation a local potentially curatively treatable with surgery and/or radiotherapy subgroup was introduced into the CUP classification. With respect to treatment of the CUP syndrome, the current guidelines present options beyond empirical chemotherapy, which is still the gold standard treatment, and pinpoint indications and predictive biomarkers for targeted and immune checkpoint inhibitor treatment.
UNASSIGNED: The aim of this review is to present the current state of diagnostics, classification and treatment of CUP syndrome, with a focus on recent developments and revisions implemented in the current ESMO guidelines.
UNASSIGNED: HINTERGRUND: Als CUP-Syndrom („cancer of unknown primary“) bezeichnet man eine Krebserkrankung, die histologisch aus Metastasengewebe gesichert ist, bei der aber trotz ausführlicher Diagnostik kein Primärtumor nachgewiesen werden kann. Damit handelt es sich beim CUP-Syndrom um eine Ausschlussdiagnose.
UNASSIGNED: Aktuell hat die European Society of Medical Oncology (ESMO) stark überarbeitete Leitlinien zum CUP-Syndrom herausgegeben. Folgende relevante Aktualisierungen sind vorgenommen worden: Bei der Diagnose des CUP-Syndroms zielen die neuen Leitlinien darauf ab, die Erkrankung präziser zu definieren und die Diagnose anhand von Algorithmen besser zu standardisieren. Auch wird die molekulare Diagnostik am Tumorgewebe in den neuen Empfehlungen verankert. Die Klassifikation des CUP-Syndroms wurde ebenfalls überarbeitet. Zum einen wurde bei der Neudefinition der günstigen Untergruppen, für die eine spezifische Behandlung indiziert ist, das Karzinom mit nierenzellkarzinomtypischer Immunhistochemie („renal-like CUP“) neu aufgenommen. Zum anderen wurde eine lokal mittels Operation und/oder Strahlentherapie potenziell kurativ behandelbare Subgruppe basierend auf einer neu definierten oligometastasierten Situation in die CUP-Klassifikation eingeführt. Bezüglich der Therapie der CUP-Syndrome zeigen die aktuellen Leitlinien auf, in welchen Indikationen jenseits der empirischen Chemotherapie, die immer noch den therapeutischen Goldstandard darstellt, auch Immuntherapien und zielgerichtete Therapien zum Einsatz kommen können.
UNASSIGNED: Ziel dieser Übersichtsarbeit ist es, den aktuellen Stand der Diagnostik, Klassifikation und Therapie des CUP-Syndroms aufzuzeigen und dabei insbesondere die aktuellen Entwicklungen und die in den revidierten ESMO-Leitlinien vorgenommenen Änderungen darzustellen.

Over the past few years, there have been many developments in the treatment of advanced breast cancer; these have been incorporated into national and international treatment guidelines, resulting in an improved prognosis for these patients. The 6th International Consensus Conference for Advanced Breast Cancer (ABC6) was held in November 2021. The aim is to standardize the treatment of advanced breast cancer based on a high level of evidence, and to make new treatment options accessible to all patients. In this article we discuss the ABC6 consensus in the context of German treatment guidelines, and compare it with clinical practice in Germany. The authors refer to the current recommendations of the Breast Cancer Working Group for Gynecological Oncology (AGO Mamma) published in March 2022. The AGO Breast Cancer Guidelines are updated annually. Since discrepancies between national and international guidelines can occur due to country-specific regulations, this is a useful comparison to make. The German authors refer to the voting results of the ABC6 panelists from 6 November 2021.

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.
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.
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.

Non-small cell lung cancer (NSCLC) is a heterogeneous disease accounting for approximately 85% of all lung cancers. Only 17% of patients are diagnosed at an early stage. Treatment is multidisciplinary and radiotherapy plays a key role in all stages of the disease. More than 50% of patients with NSCLC are treated with radiotherapy (curative-intent or palliative). Technological advances-including highly conformal radiotherapy techniques, new immobilization and respiratory control systems, and precision image verification systems-allow clinicians to individualize treatment to maximize tumor control while minimizing treatment-related toxicity. Novel therapeutic regimens such as moderate hypofractionation and advanced techniques such as stereotactic body radiotherapy (SBRT) have reduced the number of radiotherapy sessions. The integration of SBRT into routine clinical practice has radically altered treatment of early-stage disease. SBRT also plays an increasingly important role in oligometastatic disease. The aim of the present guidelines is to review the role of radiotherapy in the treatment of localized, locally-advanced, and metastatic NSCLC. We review the main radiotherapy techniques and clarify the role of radiotherapy in routine clinical practice. These guidelines are based on the best available evidence. The level and grade of evidence supporting each recommendation is provided.