Department of Experimental Clinical Oncology.
Department of Medical Physics, Aarhus University Hospital.
Radiother Oncol. 2014 Jun;111(3):366-73. doi: 10.1016/j.radonc.2014.05.004. Epub 2014 Jun 5.
Several epidemiological studies have reported increased risks of second lung cancers after breast cancer irradiation. In this study we assessed the effects of the delivered radiation dose to the lung and the risk of second primary lung cancer.
We conducted a nested case-control study of second lung cancer in a population based cohort of 23,627 early breast cancer patients treated with post-operative radiotherapy from 1982 to 2007. The cohort included 151 cases diagnosed with second primary lung cancer and 443 controls. Individual dose-reconstructions were performed and the delivered dose to the center of the second lung tumor and the comparable location for the controls were estimated, based on the patient specific radiotherapy charts.
The median age at breast cancer diagnosis was 54 years (range 34-74). The median time from breast cancer treatment to second lung cancer diagnosis was 12 years (range 1-26 years). 91% of the cases were categorized as ever smokers vs. 40% among the controls. For patients diagnosed with a second primary lung cancer five or more years after breast cancer treatment the rate of lung cancer increased linearly with 8.5% per Gray (95% confidence interval=3.1-23.3%; p<0.001). This rate was enhanced for ever smokers with an excess rate of 17.3% per Gray (95% CI=4.5-54%; p<0.005).
Second lung cancer after radiotherapy for early breast cancer is associated with the delivered dose to the lung. Although the absolute risk is relative low, the growing number of long-time survivors after breast cancer treatment highlights the need for advances in normal tissue sparing radiation techniques.
几项流行病学研究报告称，乳腺癌放疗后发生第二肺癌的风险增加。在这项研究中，我们评估了肺接受的辐射剂量与第二原发性肺癌风险的关系。
我们对 1982 年至 2007 年间接受术后放疗的 23627 例早期乳腺癌患者进行了一项基于人群的队列研究，以确定第二原发性肺癌的病例。该队列包括 151 例诊断为第二原发性肺癌的患者和 443 例对照。根据患者特定的放疗图表，对个体剂量进行了重建，并估计了第二肺肿瘤中心和对照组可比部位的剂量。
乳腺癌诊断时的中位年龄为 54 岁（范围 34-74 岁）。从乳腺癌治疗到第二肺癌诊断的中位时间为 12 年（范围 1-26 年）。91%的病例为曾经吸烟者，而对照组中这一比例为 40%。对于乳腺癌治疗后 5 年或以上诊断为第二原发性肺癌的患者，肺癌的发病率呈线性增加，每格雷增加 8.5%（95%置信区间=3.1-23.3%；p<0.001）。对于曾经吸烟者，这种比率因每格雷增加 17.3%而增强（95%置信区间=4.5-54%；p<0.005）。
早期乳腺癌放疗后发生第二肺癌与肺接受的剂量有关。尽管绝对风险相对较低，但乳腺癌治疗后长期生存人数的增加突显了需要在正常组织保护放疗技术方面取得进展。
