Nilsson G, Holmberg L, Garmo H, Terent A, Blomqvist C
Department of Oncology, Radiology and Clinical Immunology, University Hospital, Uppsala, Sweden.
Br J Cancer. 2009 Mar 10;100(5):811-6. doi: 10.1038/sj.bjc.6604902.
The aim of this study was to assess whether adjuvant treatment of breast cancer (BC) affects the risk of stroke, and to explore radiation targets and fraction doses regarding risk and location of stroke. In a Swedish BC cohort diagnosed during 1970-2003, we carried out a nested case-control study of stroke after BC, with relevant details extracted from medical records. The odds ratio (OR) for radiotherapy (RT) vs that of no RT did not differ between cases and controls (OR=0.85; confidence interval, CI=0.6-1.3). Radiotherapy to internal mammary chain (IMC) and supraclavicular (SCL) lymph nodes vs that of no RT was associated with a higher, although not statistically significant, risk of stroke (OR=1.3; CI=0.8-2.2). In a pooled analysis, RT to IMC and SCL vs the pooled group of no RT and RT to breast/chest wall/axilla (but not IMC and SCL), showed a significant increase of stroke (OR=1.8; CI=1.1-2.8). There were no associations between cancer laterality, targets of RT, and location of stroke. The radiation targets, IMC and SCL, showed a statistically significant trend for an increased risk of stroke with daily fraction dose. Our finding of a target-specific increased risk of stroke and a dose-response relationship for daily fraction dose, indicate that there may be a causal link between RT to the IMC and SCL and risk of stroke.
本研究的目的是评估乳腺癌（BC）辅助治疗是否会影响中风风险，并探讨与中风风险和部位相关的放疗靶区和分次剂量。在1970年至2003年期间确诊的瑞典BC队列中，我们对BC后中风进行了一项巢式病例对照研究，从医疗记录中提取相关细节。放疗（RT）与未放疗的病例与对照之间的比值比（OR）无差异（OR = 0.85；置信区间，CI = 0.6 - 1.3）。内乳链（IMC）和锁骨上（SCL）淋巴结放疗与未放疗相比，中风风险虽无统计学意义但更高（OR = 1.3；CI = 0.8 - 2.2）。在一项汇总分析中，IMC和SCL放疗与未放疗及乳房/胸壁/腋窝（但不包括IMC和SCL）放疗的汇总组相比，中风显著增加（OR = 1.8；CI = 1.1 - 2.8）。癌症侧别、放疗靶区与中风部位之间无关联。放疗靶区IMC和SCL显示中风风险随每日分次剂量增加有统计学意义的趋势。我们发现特定靶区中风风险增加以及每日分次剂量存在剂量反应关系，这表明IMC和SCL放疗与中风风险之间可能存在因果联系。
