Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark.
Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark; Department of Oncology, Aarhus University Hospital, Denmark.
Radiother Oncol. 2021 Apr;157:106-113. doi: 10.1016/j.radonc.2021.01.010. Epub 2021 Jan 27.
Radiotherapy (RT) for early breast cancer (BC) reduces the risk of recurrence and improves overall survival. However, thoracic RT may cause some incidental RT dose to the heart with subsequent risk of heart disease. During 2000-2010, CT-based RT planning was gradually introduced. The aim of this study was to investigate the risk of cardiac events in left-sided compared with right-sided BC patients treated during a non-CT-based (1999-2007) vs a CT-based period (2008-2016).
Information on BC and cardiac events among Danish women was obtained from population-based medical registers. Patients diagnosed with BC during 1999-2016, were included. A cardiac event was defined as coronary artery disease or severe valvular heart disease.
Among 29,662 patients, 22,056 received RT. For those irradiated during the non-CT-based period, the 10-year cumulative risk of cardiac event was 1.7% (95% CI 1.4-2.0) at median follow-up of 11.1 years. The incidence rate ratio (IRR) for cardiac event in left-sided vs right-sided patients was 1.44 (1.07-1.94) and a trend towards worse outcome was seen within the first 10 years after RT and approached statistical significance with longer follow-up. Among patients irradiated during the CT-based period, the 10-year cumulative risk of cardiac event was 2.1% (1.8-2.4) at median 6.8 years follow-up. The IRR for cardiac event in left-sided vs right-sided patients was 0.90 (0.69-1.16) and no trend towards worse outcome within the first 10 years was observed.
This study confirmed a higher risk of cardiac events in left-sided vs right-sided BC patients irradiated during a non-CT-based period. For patients irradiated during a CT-based period, no increased risk of cardiac events in left-sided vs right-sided patients was observed within the first 10 years after RT, whilst information on cardiac events beyond 10 years after RT was limited.
早期乳腺癌（BC）的放射治疗（RT）可降低复发风险并提高总体生存率。然而，胸部 RT 可能会导致心脏偶然受到一些 RT 剂量，从而增加患心脏病的风险。在 2000-2010 年期间，逐渐引入了基于 CT 的 RT 规划。本研究的目的是调查与右侧 BC 患者相比，左侧 BC 患者在非 CT （1999-2007）与 CT （2008-2016）期间接受治疗的心脏事件风险。
从基于人群的医学登记处获得了丹麦女性的 BC 和心脏事件信息。包括 1999-2016 年期间诊断为 BC 的患者。心脏事件定义为冠心病或严重瓣膜性心脏病。
在 29662 名患者中，有 22056 名接受了 RT。对于在非 CT 基础治疗期间接受放射治疗的患者，中位随访 11.1 年后 10 年累积心脏事件风险为 1.7%（95%CI 1.4-2.0）。左侧与右侧患者的心脏事件发生率比（IRR）为 1.44（1.07-1.94），并且在 RT 后前 10 年内观察到趋势并随着随访时间的延长接近统计学意义。在 CT 基础治疗期间接受放射治疗的患者中，中位随访 6.8 年后 10 年累积心脏事件风险为 2.1%（1.8-2.4）。左侧与右侧患者的心脏事件 IRR 为 0.90（0.69-1.16），并且在前 10 年内未观察到心脏事件恶化的趋势。
本研究证实，在非 CT 基础治疗期间，左侧与右侧 BC 患者接受放射治疗的心脏事件风险更高。对于在 CT 基础治疗期间接受放射治疗的患者，在 RT 后前 10 年内，左侧与右侧患者的心脏事件风险未见增加，而 RT 后 10 年以上的心脏事件信息有限。
