Pravosud Vira, Huang Bin, Tucker Thomas, Vanderford Nathan L
From the Departments of Epidemiology, Cancer Biostatistics, Toxicology, and Cancer Biology, Rural Cancer Prevention Center, College of Medicine, University of Kentucky, Lexington.
South Med J. 2017 Dec;110(12):775-781. doi: 10.14423/SMJ.0000000000000742.
The aim of this study was to investigate whether patients with lung cancer in Appalachian Kentucky are more likely to develop multiple primary cancers than patients in non-Appalachian Kentucky. Additional analyses were conducted to identify other factors that may be associated with an increased hazard of developing multiple primary cancers in patients with lung cancer.
The data for this retrospective, population-based cohort study of 26,456 primary lung cancer patients were drawn from the Kentucky Cancer Registry. For inclusion in the study, patients must have been diagnosed between January 1, 2000 and December 31, 2013 and they must either have continually resided in Appalachian Kentucky or continually resided in non-Appalachian Kentucky. Cases were excluded if the patient was diagnosed as having additional primary cancers within 3 months of the initial diagnosis of primary lung cancer. The medical records for each case were examined to determine whether the patient was subsequently diagnosed as having additional primary cancers. The Cox proportional hazards model was then used to assess whether there was an association between the region in which the patients live and the likelihood of developing multiple primary cancers. Time to event was considered as the time from diagnosis to either death or development of a second primary cancer.
The results presented here indicate that the risk of developing multiple primary cancers is the same for patients with lung cancer throughout Kentucky (hazard ratio [HR] 1.002, = 0.9713). We found no evidence for a greater hazard in patients from Appalachia; however, additional analyses revealed several high-risk groups. Male patients and older patients had a significantly greater hazard of developing multiple primary cancers (HR 1.169, = 0.012 and 1.015, = 0.0001, respectively). In addition, patients who underwent surgery and those who were diagnosed initially as having an earlier stage of cancer also were more likely to develop multiple primary cancers (HR 1.446, = 0.0003 and 0.684, = 0.0015, respectively).
This is a negative study. Patients with primary lung cancer living in Appalachian Kentucky are not at a greater risk of developing multiple primary cancers than those residing in non-Appalachian Kentucky. High-risk groups identified in this study are male patients and older patients. The increased hazard seen in patients who underwent surgery or those who were diagnosed as having earlier stages of lung cancer are likely an artifact of these patients living longer and, therefore, having more time to develop additional primary cancers.
本研究旨在调查肯塔基州阿巴拉契亚地区的肺癌患者是否比非阿巴拉契亚地区的肺癌患者更易患多发性原发性癌症。还进行了其他分析，以确定可能与肺癌患者发生多发性原发性癌症风险增加相关的其他因素。
这项基于人群的回顾性队列研究纳入了26456例原发性肺癌患者的数据，数据来自肯塔基州癌症登记处。纳入研究的患者必须在2000年1月1日至2013年12月31日期间被诊断，且必须一直居住在肯塔基州阿巴拉契亚地区或一直居住在非阿巴拉契亚地区。如果患者在原发性肺癌初次诊断后3个月内被诊断患有其他原发性癌症，则将其排除。检查每个病例的病历，以确定患者随后是否被诊断患有其他原发性癌症。然后使用Cox比例风险模型评估患者居住地区与发生多发性原发性癌症可能性之间是否存在关联。事件发生时间被视为从诊断到死亡或发生第二种原发性癌症的时间。
此处呈现的结果表明，肯塔基州各地的肺癌患者发生多发性原发性癌症的风险相同（风险比[HR]为1.002，P = 0.9713）。我们没有发现阿巴拉契亚地区患者风险更高的证据；然而，进一步分析发现了几个高危组。男性患者和老年患者发生多发性原发性癌症的风险显著更高（HR分别为1.169，P = 0.012和1.015，P = 0.0001）。此外，接受手术的患者和最初被诊断为癌症早期的患者也更有可能发生多发性原发性癌症（HR分别为1.446，P = 0.0003和0.684，P = 0.0015）。
这是一项阴性研究。居住在肯塔基州阿巴拉契亚地区的原发性肺癌患者发生多发性原发性癌症的风险并不高于居住在非阿巴拉契亚地区的患者。本研究确定的高危组是男性患者和老年患者。手术患者或被诊断为肺癌早期患者中观察到的风险增加可能是这些患者存活时间更长的结果，因此有更多时间发生其他原发性癌症。
