Atkins Graham T, Kim Taeha, Munson Jeffrey
1 Section of Pulmonary Medicine.
2 Department of Internal Medicine, and.
Ann Am Thorac Soc. 2017 Mar;14(3):403-411. doi: 10.1513/AnnalsATS.201606-469OC.
There is increased lung cancer mortality in rural areas of the United States. However, it remains unclear to what extent rural-urban differences in disease incidence, stage at diagnosis, or treatment explain this finding.
To explore the relationship between smoking rates, lung cancer incidence, and lung cancer mortality in populations across the rural-urban continuum and to determine whether survival is decreased in rural patients diagnosed with lung cancer and whether this is associated with rural-urban differences in stage at diagnosis or the treatment received.
We conducted a retrospective cohort study of 348,002 patients diagnosed with lung cancer between 2000 and 2006. Data from metropolitan, urban, suburban, and rural areas in the United States were obtained from the Surveillance, Epidemiology, and End Results program database. County-level population estimates for 2003 were obtained from the U.S. Census Bureau, and corresponding estimates of smoking prevalence were obtained from published literature. The exposure was rurality, defined by the rural-urban continuum code area linked to each cohort participant by county of residence. Outcomes included lung cancer incidence, mortality, diagnostic stage, and treatment received.
Lung cancer mortality increased with rurality in a dose-dependent fashion across the rural-urban continuum. The most rural areas had almost twice the smoking prevalence and lung cancer incidence of the largest metropolitan areas. Rural patients diagnosed with stage I non-small cell lung cancer underwent fewer surgeries (69% vs. 75%; P < 0.001) and had significantly reduced median survival (40 vs. 52 mo; P = 0.0006) compared with the most urban patients. Stage at diagnosis was similar across the rural-urban continuum, as was median survival for patients with stages II-IV lung cancer.
Higher rural smoking rates drive increased disease incidence and per capita lung cancer mortality in rural areas of the United States. There were no rural-urban discrepancies in diagnostic stage, suggesting similar access to diagnostic services. Rural patients diagnosed with stage I non-small cell lung cancer had shorter survival, which may reflect disparities in access to surgical care. No survival difference for patients with advanced-stage lung cancer is attributed to lack of effective treatment during the time period of this study.
美国农村地区肺癌死亡率有所上升。然而，疾病发病率、诊断时的分期或治疗方面的城乡差异在多大程度上能解释这一发现仍不清楚。
探讨城乡连续体人群中吸烟率、肺癌发病率和肺癌死亡率之间的关系，并确定农村肺癌患者的生存率是否降低，以及这是否与诊断时的分期或所接受的治疗方面的城乡差异有关。
我们对2000年至2006年间诊断为肺癌的348,002例患者进行了一项回顾性队列研究。美国大都市、城市、郊区和农村地区的数据来自监测、流行病学和最终结果（SEER）项目数据库。2003年县级人口估计数来自美国人口普查局，相应的吸烟流行率估计数来自已发表的文献。暴露因素为农村地区情况，通过根据居住县与每个队列参与者相关联的城乡连续体代码区域来定义。结局包括肺癌发病率、死亡率、诊断分期和所接受的治疗。
在城乡连续体中，肺癌死亡率随着农村地区情况的增加呈剂量依赖性增加。最偏远农村地区的吸烟流行率和肺癌发病率几乎是最大都市地区的两倍。与最城市地区的患者相比，诊断为I期非小细胞肺癌的农村患者接受手术的比例较低（69%对75%；P<0.001），中位生存期显著缩短（40个月对52个月；P=0.0006）。在城乡连续体中，诊断时的分期相似，II-IV期肺癌患者的中位生存期也相似。
美国农村地区较高的吸烟率导致疾病发病率和人均肺癌死亡率上升。在诊断分期方面不存在城乡差异，这表明获得诊断服务的机会相似。诊断为I期非小细胞肺癌的农村患者生存期较短，这可能反映了获得手术治疗的机会存在差异。晚期肺癌患者无生存差异归因于本研究期间缺乏有效的治疗。
