Munich Cancer Registry (MCR), Institute for Medical Information Processing, Biometry and Epidemiology (IBE), Ludwig-Maximilians-University (LMU), 81377, Munich, Germany.
The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, NH, 03756, USA.
J Cancer Res Clin Oncol. 2020 Aug;146(8):2041-2049. doi: 10.1007/s00432-020-03264-0. Epub 2020 May 29.
In breast cancer (BC), the duration of endocrine adjuvant therapies (AT) has been extended continuously up to 10 years. We present an alternative explanation for the effect, which could enable shorter treatments.
The relevant literature on chemoprevention and (neo-)adjuvant therapy was reviewed. Data for initiation and growth of primary and contralateral BCs and their metastases (MET) were considered. Also, population-based data from the Munich Cancer Registry for MET-free survival, time trends of MET patterns, and survival achieved by improved ATs are used to estimate all events in the long-term follow-up.
Extended ATs (EAT) that continue after 1, 2, or 5 years reduce mortality only slightly. The effect is delayed, occurring more than 5 years after extension. EATs does not affect the prognosis of 1stBCs, they preventively eradicate contralateral 2ndBCs and thus their future life-threatening METs. Because chemoprevention can eradicate BCs from the smallest clusters to almost detectable BCs, ATs can be temporarily suspended without imposing harm. Results equal to EATs can be achieved by short-term ATs of the 1stBC and by repeated neo-ATs targeted at the indefinitely developing 2ndBCs. Considering this potential in de-escalation, a 70-80% reduction of overtreatment seems possible.
Knowledge of initiation and growth of tumors with known effects of neo-ATs suggest that intermittent endocrine ATs may achieve the same results as EATs but with improved quality of life and survival because of fewer side effects and better compliance. The challenge for developments of repeated ATs becomes: how short is short enough.
在乳腺癌（BC）中，内分泌辅助治疗（AT）的持续时间已连续延长至 10 年。我们提出了一种可能的替代解释，这可以使治疗时间更短。
综述了化学预防和（新）辅助治疗的相关文献。考虑了原发性和对侧 BC 及其转移（MET）的起始和生长数据。此外，还利用慕尼黑癌症登记处的基于人群的数据来评估无 MET 生存率、MET 模式的时间趋势以及通过改进 AT 获得的生存情况，以估计长期随访中的所有事件。
延长至 1、2 或 5 年后的延长 AT（EAT）仅略微降低死亡率。该效果延迟，在延长后超过 5 年发生。EAT 不会影响 1 期 BC 的预后，它们可预防性地消除对侧 2 期 BC 及其未来危及生命的 MET。由于化学预防可以从最小的簇中消除 BC 到几乎可检测的 BC，因此可以暂时暂停 AT 而不会造成伤害。通过对 1 期 BC 进行短期 AT 和对不断发展的 2 期 BC 进行重复新 AT，可以实现与 EAT 相等的结果。考虑到这种降级的潜力，过度治疗的减少 70-80%似乎是可能的。
对具有新 AT 已知效果的肿瘤起始和生长的了解表明，间歇性内分泌 AT 可能会达到与 EAT 相同的效果，但由于副作用更少和更好的依从性，生活质量和生存会得到改善。重复 AT 发展的挑战是：多短才算短。
