INTRODUCTION Synchronous oligometastatic disease (sOM) is an oncological concept, characterized by a limited cancer burden. Oligometastatic patients could potentially benefit from local radical treatments. Despite the fact that the sOM condition is well recognized, a universal definition, including a specific definition for non-small cell lung cancer (NSCLC), is not yet available. The aim of this systematic review is to resume sOM definitions and staging requirement used in NSCLC. METHODS The key issue was formulated in one research question according to the PICO strategy. The question was introduced in MEDLINE (OvidSP). All articles dealing with sOM-NSCLC and providing a definition of sOM-NSCLC were selected and analyzed. RESULTS A total of twenty-one eligible articles focusing on sOM NSCLC were retrieved and analyzed. In 17 studies (81%), patients had to be staged with magnetic resonance or computed tomography (CT) of the brain, thoracic and abdominal CT and positron emission tomography. The total number of metastases allowed in the definitions ranged between 1 and 8, but in 38.1% of studies the maximum number was 5. Most of the publications did not define the number of involved organs and the maximum number of metastases per organ. For mediastinal lymph-node involvement, only 5 (27.8%) articles counted this as a metastatic site. CONCLUSIONS No uniform definition of sOM-NSCLC could be retrieved by this systematic review. However, extended staging was mandated in the majority of studies. An accepted oncological definition of sOM is essential for patient selection in order to define prospective clinical trials.

中文翻译：

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定义同步寡转移性非小细胞肺癌：系统评价

引言同步性寡转移性疾病 (sOM) 是一个肿瘤学概念，其特点是癌症负担有限。寡转移患者可能受益于局部根治性治疗。尽管 sOM 条件已得到广泛认可，但尚无通用定义，包括非小细胞肺癌 (NSCLC) 的特定定义。本系统评价的目的是恢复 NSCLC 中使用的 sOM 定义和分期要求。方法 根据 PICO 策略，将关键问题表述为一个研究问题。这个问题是在 MEDLINE (OvidSP) 中引入的。选择并分析了所有涉及 sOM-NSCLC 并提供 sOM-NSCLC 定义的文章。结果 检索和分析了总共 21 篇关于 sOM NSCLC 的符合条件的文章。在 17 项研究 (81%) 中，患者必须进行脑部磁共振或计算机断层扫描 (CT)、胸腹部 CT 和正电子发射断层扫描。定义中允许的转移总数在 1 到 8 之间，但在 38.1% 的研究中，最大转移数为 5。大多数出版物没有定义受累器官的数量和每个器官的最大转移数。对于纵隔淋巴结受累，只有 5 篇（27.8%）文章将其视为转移部位。结论 本系统评价无法检索到 sOM-NSCLC 的统一定义。然而，大多数研究都要求延长分期。接受 sOM 的肿瘤学定义对于选择患者以定义前瞻性临床试验至关重要。