INTRODUCTION In incidence lung cancer screening rounds, new pulmonary nodules are regular findings. They have a higher lung cancer probability than baseline nodules. Previous studies showed that baseline perifissural nodules (PFNs) represent benign lesions. Whether this is also the case for incident PFNs is unknown. This study evaluated newly detected nodules in the Dutch-Belgian randomized-controlled NELSON study with respect to incidence of fissure-attached nodules, their classification, and lung cancer probability. METHOD Within the NELSON trial, 7,557 participants underwent baseline screening between April 2004 and December 2006. Participants with new nodules detected after baseline were included. Nodules were classified based on location and attachment. Fissure-attached nodules were re-evaluated to be classified as typical, atypical or non-PFN by two radiologists without knowledge of participant lung cancer status. RESULT 1,484 new nodules were detected in 949 participants (77.4% male, median age 59 [interquartile range: 55-63]) in the second, third and final NELSON screening round. Based on 2-year follow-up or pathology, 1,393 nodules (93.8%) were benign. In total, 97 (6.5%) were fissure-attached, including 10 malignant nodules. None of the new fissure-attached malignant nodules was classified as a typical or atypical PFN. CONCLUSION In the NELSON study, 6.5% of incident lung nodules were fissure-attached. None of the lung cancers that originated from a new fissure-attached nodule in the incidence lung cancer screening rounds was classified as a typical or atypical PFN. Our results suggest that also in the case of a new PFN, it is highly unlikely that these PFNs will be diagnosed as lung cancer.

中文翻译：

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肺癌筛查中新的裂隙附着结节：尼尔森研究的简要报告

简介 在肺癌筛查中，新发肺部结节是常见的发现。与基线结节相比，它们患肺癌的可能性更高。先前的研究表明，基线裂周结节（PFN）代表良性病变。事件 PFN 是否也是如此尚不清楚。本研究评估了荷兰-比利时随机对照 NELSON 研究中新发现的结节，包括裂隙附着结节的发生率、分类和肺癌概率。方法 在 NELSON 试验中，2004 年 4 月至 2006 年 12 月期间，7,557 名参与者接受了基线筛查。基线后检测到新结节的参与者也被纳入其中。结节根据位置和附着情况进行分类。两名放射科医生在不了解参与者肺癌状况的情况下重新评估了裂隙附着结节，将其分类为典型、非典型或非 PFN。结果 在第二轮、第三轮和最后一轮 NELSON 筛查中，949 名参与者（77.4% 为男性，中位年龄 59 岁 [四分位距：55-63]）中检测到 1,484 个新结节。根据 2 年随访或病理结果，1,393 个结节 (93.8%) 为良性。总共有 97 个 (6.5%) 存在裂隙附着，其中包括 10 个恶性结节。没有一个新的裂隙附着恶性结节被分类为典型或非典型 PFN。结论 在 NELSON 研究中，6.5% 的肺结节是裂隙附着的。在发病率肺癌筛查轮次中，没有任何起源于新的裂隙附着结节的肺癌被归类为典型或非典型 PFN。我们的结果表明，对于新的 PFN，这些 PFN 被诊断为肺癌的可能性也很小。