Oligometastatic disease (OMD) is currently known as an intermediate state of cancer, characterized by a limited number of systemic metastatic lesions for which local ablative therapy could be curative. Indeed, data from multiple clinical trials have illustrated an increase in overall survival (OS) for cancer patients when local ablative therapy was included in the systemic adjuvant therapy. Given that no driver and somatic mutations specific to OMD are currently established, the diagnosis of OMD is mainly based on the results of X-ray studies. In 2020, 20 international experts from the European Society for Radiotherapy and Oncology (ESTRO) and the European Organization for Research and Treatment of Cancer (EORTC) developed a comprehensive system for the characterization and classification of OMD. They identified 17 OMD characteristics that needed to be assessed in all patients who underwent radical local treatment. These characteristics reflect the tumor biology and clinical features of the disease underlying the development of OMD independently of the primary tumor type and the number of metastatic lesions. In particular, the system involves the characteristics of the primary tumor (e.g., localization, histology, TNM stage, mutational status, specific tumor markers), clinical parameters (e.g., disease-free interval, treatment-free interval), therapies (e.g., local, radical or palliative treatment, the numbers of the therapeutic regimens), and type of OMD (e.g., invasive). Based on the aforementioned criteria, an algorithm was introduced into the clinic to classify OMDs collectively according to their nomenclature. A history of polymetastatic disease (PMD) prior to OMD is used as a criterion to delineate between induced OMD (previous history of PMD after successful therapy) and genuine OMD (no history of PMD). Genuine OMD is divided into two states: recurrent OMD (i.e., after a previous history of OMD) and de novo OMD (i.e., a first newly diagnosed oligometastatic disease). de novo OMD is differentiated into synchronous and metachronous forms depending on the length of time from the primary diagnosis to the first evidence of OMD. In the case of synchronous OMD, this period is less than 6 months. Lastly, metachronous and induced OMD are divided into oligorecurrence, oligoprogression, and oligopersistence, depending on whether OMD is firstly diagnosed during an absence (oligo recurrence) or presence (oligoprogression or oligopersistence) of active systemic therapy. This classification and nomenclature of OMD are evaluated prospectively in the OligoCare study. In this article, we present a practical review of the current concept of OMD and discuss the available prospective clinical trials and potential future directions.
寡转移性疾病（OMD）目前被认为是癌症的一种中间状态，其特征是全身转移病灶数量有限，局部消融治疗可能达到根治效果。事实上，多项临床试验数据表明，当局部消融治疗被纳入全身辅助治疗时，癌症患者的总生存期（OS）得到延长。由于目前尚未确立OMD特有的驱动基因突变和体细胞突变，OMD的诊断主要基于影像学检查结果。2020年，来自欧洲放射治疗与肿瘤学会（ESTRO）和欧洲癌症研究与治疗组织（EORTC）的20位国际专家共同制定了一套全面的OMD特征描述与分类体系。他们确定了17项需要在所有接受根治性局部治疗的患者中进行评估的OMD特征。这些特征反映了独立于原发肿瘤类型和转移病灶数量的、导致OMD发生的肿瘤生物学特性及疾病临床特点。该体系特别涵盖了原发肿瘤特征（如部位、组织学类型、TNM分期、突变状态、特异性肿瘤标志物）、临床参数（如无病间期、无治疗间期）、治疗方式（如局部治疗、根治性或姑息性治疗、治疗方案数量）以及OMD类型（如侵袭性）。基于上述标准，临床引入了一套根据命名法对OMD进行系统分类的算法。将OMD发生前的多转移性疾病（PMD）病史作为区分诱导性OMD（既往PMD病史经成功治疗后转化）与真性OMD（无PMD病史）的标准。真性OMD分为两种状态：复发性OMD（即既往有OMD病史）和初发性OMD（即首次新诊断的寡转移疾病）。根据从原发肿瘤诊断到首次出现OMD证据的时间间隔，初发性OMD又分为同步性OMD（间隔时间小于6个月）和异时性OMD。最后，根据OMD是在未接受全身治疗期间（寡复发）还是在接受全身治疗期间（寡进展或寡持续）首次诊断，将异时性OMD和诱导性OMD细分为寡复发、寡进展和寡持续三类。这套OMD分类与命名体系正在OligoCare研究中进行前瞻性验证。本文对当前OMD概念进行了实用性综述，并探讨了现有的前瞻性临床试验及未来潜在发展方向。
Oligometastatic Disease (OMD): The Classification and Practical Review of Prospective Trials
肿瘤(癌症)患者之家