A randomised phase III study of radiation doses and fractionation schedules in non-low risk DCIS of the breast

导管原位癌（DCIS）是乳腺癌的一种浸润前形式，其治疗目的是预防浸润性癌症复发。患有高风险DCIS的女性复发风险增加。本研究旨在为DCIS女性患者提供个性化治疗，以实现长期肿瘤控制，并将治疗毒性降至最低。局部切除DCIS后，放射治疗（RT）的整个乳房降低复发率。然而，目前还不清楚，如果增加辐射剂量的肿瘤床在高风险的妇女增加肿瘤控制。同样不确定的是，在3-4周内给予更少但更大的辐射剂量是否会达到与标准5-7周RT疗程相同的肿瘤控制，以改善患者的便利性和获得RT的机会。因此，这项对610名患有高风险DCIS的女性进行的多中心研究将调查在全乳腺RT后增加肿瘤床辐射增强是否会改善肿瘤控制，并且较短的RT疗程实现了与标准的较长疗程相同的肿瘤控制。目前，预测DCIS和RT毒性的恶性潜能的能力有限。本研究将使用最先进的技术研究是否存在预测DCIS女性患者浸润性复发和正常组织毒性的生物学和遗传学标记。女性需要权衡癌症控制的可能性和不良治疗效果，以做出明智的治疗决定。然而，很少有人知道的生活质量（QoL）的诊断和治疗DCIS的后果。在这项研究中，生活质量，心理困扰，浸润性癌症复发的感知风险和感知美容结果的女性DCIS，将使用一份问卷的有效措施进行评估。这项研究将根据DCIS复发的风险来完善女性DCIS的治疗。它将显著促进对DCIS生物学及其治疗后心理和生活质量结果的理解。

Treatment of ductal carcinoma in-situ (DCIS), a preinvasive form of breast cancer, is aimed at preventing invasive cancer recurrence. Women with higher-risk DCIS have an increased risk of recurrence. This study aims to individualise treatment for women with DCIS to achieve long-term tumour control with minimal treatment toxicity. After local excision of DCIS, radiotherapy (RT) to the whole breast reduces the recurrence rate. However, it is unclear if escalating radiation dose to the tumour bed in higher-risk women increases tumour control. It is also uncertain if giving fewer but larger radiation doses over 3-4 weeks would achieve the same tumour control as the standard 5-7 week course of RT to improve patient convenience and access to RT. Thus, this multicentre study of 610 women with higher-risk DCIS will investigate if adding a tumour bed radiation boost after whole breast RT improves tumour control, and the shorter RT course achieves the same tumour control as the standard longer course. Currently, the ability to predict the malignant potential of DCIS and RT toxicity is limited. This study will investigate if there are biological and genetic markers predictive of invasive recurrence and normal tissue toxicity in women with DCIS using state of the art technology. Women need to weigh up the likelihood of cancer control against adverse treatment effects to make an informed treatment decision. However, very little is known about the quality of life (QoL) consequences of the diagnosis and treatment of DCIS. In this study, the QoL, psychological distress, perceived risk of invasive cancer recurrence and perceived cosmetic outcomes of women with DCIS, will be assessed using a questionnaire of validated measures. This study will refine treatment for women with DCIS according to their risks of recurrence. It will significantly advance the understanding of the biology of DCIS and its psychological and QoL outcomes after treatment.