Introduction: Reasonable to the improved prognosis of breast cancer (BC) long-term toxicities and side effects of oncological therapy gain more importance for work ability and social life of BC patients. Aim of this study was the analysis of occurence and differences of treatment-related side effects in relation to type of rehabilitation (so-called AHB vs. later rehabilitation) after therapy for BC., Methods: Clinical and patient related data as early and late toxicities after oncological treatment of 8.000 patients with BC (55.7±10.4y) were analyzed and compared with current literature., Results: In 23.9% a mastectomy was performed, in 87.3% radiotherapy. In most cases an additional systemic treatment (57,6% CTX, 15,1% anti-Her2, 71% antihormonal treatment) was carried out. In 8.1% women suffered from recurrent or metastatic BC. As most common side effects of multimodal treatment weakness/fatigue (73,6%), insomnia (51,9%), CIPN (33%), lymph edema (13,9%) and drug-induced arthralgia (24,8%) were detected. In addition, 60.4% of women reported high levels of psychological distress. Shortly after therapy typical side effects were drug-induced toxicities (Leucopenia, p<0.0001; anemia, p<0.001; weakness/fatigue p<0.001; CIPN, p<0.0001), whereas in a later course chronic lymphedema (p<0.0001), chronic or recurrent disease (p<0.0001), status after mastectomy (p<0.0001) and psychological distress (p<0.0001) were significantly more often seen. Moreover, in this collective patients were significantly younger (53,7±9,8 vs. 56,3±10,7y)., Conclusions: In BC patients, significantly different impairments and toxicities were documented between patients with early rehabilitation and patients with later onset of rehabilitation. These data may help to establish more individual and focused rehabilitation concepts in specialized centers., Competing Interests: Die Autorinnen / Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)