Law Alastair B, Evans Tamasin, Hayward Richard L, Higgins Geoffrey S, Murray Katherine L, Summers David, Kunkler Ian H
Edinburgh Cancer Centre, UK.
Breast Care (Basel). 2009;4(1):40-42. doi: 10.1159/000193069. Epub 2009 Feb 20.
BACKGROUND: Trastuzumab is used as adjuvant treatment in patients with HER2-positive breast cancers and has been shown to reduce the chance of recurrence by up to 50%. However, experience with it given with radiotherapy is limited and there is in vitro evidence of a radiosensiti-sation effect. We describe the first case of trastuzumab-associated radiation-induced myelitis. CASE REPORT: This patient received a calculated dose of 28 Gy to the spinal cord when receiving adjuvant radiotherapy to the chest wall and supraclavicular and axillary lymph nodes. This is well below the accepted radiation tolerance of the spinal cord (50-60 Gy) but she developed radiation-induced myelitis of her spinal cord with characteristic magnetic resonance imaging changes. We postulate that trastuzu-mab given concurrently with radiation may have acted as a radiosensitiser and that normal repair mechanisms in the acute stage were affected by trastuzumab blockage of epidermal growth factor receptors, resulting in demy-elination at a lower dose of radiation than normally seen. CONCLUSIONS: Concomitant radiotherapy and adjuvant trastuzumab treatment should be given with caution and consideration made of delaying trastuzumab until after radiotherapy has been completed. As longer-term data become available for patients who received trastuzumab and radiation, it will become clearer whether there is a significant interaction on organs such as the heart and spinal cord in the radiation field.
背景：曲妥珠单抗用于HER2阳性乳腺癌患者的辅助治疗，已显示可将复发几率降低多达50%。然而，其与放疗联合应用的经验有限，且有体外证据表明存在放射增敏作用。我们描述了首例曲妥珠单抗相关的放射性脊髓炎病例。病例报告：该患者在接受胸壁、锁骨上及腋窝淋巴结辅助放疗时，脊髓接受的计算剂量为28 Gy。这远低于公认的脊髓放射耐受剂量（50 - 60 Gy），但她出现了具有特征性磁共振成像改变的放射性脊髓炎。我们推测，放疗期间同时给予曲妥珠单抗可能起到了放射增敏剂的作用，急性期的正常修复机制受到曲妥珠单抗对表皮生长因子受体的阻断影响，导致在低于正常所见剂量的辐射下发生脱髓鞘。结论：放疗与辅助性曲妥珠单抗治疗应谨慎联合应用，考虑在放疗完成后再给予曲妥珠单抗。随着接受曲妥珠单抗和放疗患者的长期数据不断可得，放疗区域内心脏和脊髓等器官是否存在显著相互作用将变得更加清晰。
