BACKGROUND Lung cancer with lung to lung metastasis is common. The objective of this study was to investigate the association among the distribution of contralateral lung metastases versus primary lung tumor location, clinical characteristics, and epidermal growth factor receptor (EGFR) mutations status. METHODS The study included treatment-naïve stage IV lung adenocarcinoma with contralateral lung metastases from 2012 through 2013. RESULTS In total, 103 patients were enrolled after excluding lung cancer with histology other than adenocarcinoma, synchronous multiple primary lung cancers, or other active malignancy. The median age was 65 years (range, 28-93 years); 47 male patients (45.6%); 69 non-smoker (NS) patients (67.0%); 68 Eastern Cooperative Oncology Group performance status (ECOG PS) 0-1 patients (66.0%); 38 M1a patients (38.9%); and 60 EGFR mutation patients (58.3%). There were 51 cases (49.5%) with primary lung cancer located over upper lobes. Among them, 36 (70.6%) had contralateral upper lung predominance metastasis, 9 (17.6%) had lower lung predominance, and 6 (11.8%) had equal distribution. Among the 52 lower lobe tumors, 17 (32.7%), 19 (36.5%), and 16 (30.8%) had upper, lower lung predominance, and equal distribution metastasis, respectively. Univariate analysis showed only male gender and primary tumor location over upper lobes were significantly associated with contralateral upper lung predominance metastases. After multivariate analysis, only primary tumor location over upper lobes was significantly associated with contralateral upper lung predominance metastases (adjusted OR 5.49, 95% CI, 2.15-14.03, P<0.001). CONCLUSIONS Upper lobe lung adenocarcinoma was significantly associated with contralateral upper lung predominance metastases. Further research is needed to elucidate the mechanisms underlying this phenomenon.

中文翻译：

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上叶肺腺癌患者对侧上肺转移的好发。

背景技术肺癌具有肺到肺转移是常见的。这项研究的目的是调查对侧肺转移的分布与原发性肺肿瘤位置，临床特征和表皮生长因子受体（EGFR）突变状态之间的关联。方法该研究包括从2012年到2013年的初治IV期肺腺癌，并伴有对侧肺转移。结果总共有103例患者被排除在组织学检查之外的肺癌中，除了腺癌，同步多发性原发性肺癌或其他活动性恶性肿瘤。中位年龄为65岁（范围为28-93岁）；男47例（45.6％）; 69名非吸烟（NS）患者（67.0％）；68东部合作肿瘤小组表现状态（ECOG PS）0-1例（66.0％）；38例M1a患者（38.9％）; 60例EGFR突变患者（58.3％）。原发性肺癌位于上叶上方的病例为51例（49.5％）。其中，对侧上肺占优势转移有36（70.6％），下肺占优势有9（17.6％），等分分布有6（11.8％）。在52例下叶肿瘤中，分别有17例（32.7％），19例（36.5％）和16例（30.8％）具有较高，较低的肺优势和均等的转移。单因素分析显示，仅男性性别和上叶上方的原发肿瘤位置与对侧上肺优势转移显着相关。经过多变量分析后，仅原发肿瘤位于上叶上方与对侧上肺优势转移显着相关（校正OR 5.49，95％CI，2.15-14.03，P <0.001）。结论上叶肺腺癌与对侧上肺优势转移密切相关。需要进一步研究以阐明这种现象的潜在机制。