Long term side effects of adjuvant chemotherapy in patients with early breast cancer.

Adjuvant systemic therapy along with screening has been key to the observed improvements in disease-free and overall survival (DFS/OS) in breast cancer. Improvements in overall survival already take into account therapy related toxicities that can result in death. However, this measure alone does not adequately capture the impact on health-related quality of life. Therefore, it is important to examine the prevalence, frequency and short/long-term impact of therapy-related toxicities, identify patients who might be at greatest risk. Ultimately decisions regarding expected therapy benefits (relative and absolute percentage improvements in DFS/OS) must be made against a background of known potential harms. For many patients with early breast cancer (EBC), their risk of recurrence is not zero but is small. At the same time, for many therapies for early stage breast cancer, the risk of serious side effects is small but is not zero. As we better understand the long-term side effects of adjuvant chemotherapy and targeted therapy, it becomes critical to integrate our growing understanding of breast cancer biology with standard high-quality histopathologic measures to better identify the patients most likely to benefit from the various options for combined multimodality therapy. Hence, we must strive against the notion of recommending adjuvant systemic chemotherapy "just in case." This article focuses on the long-term side effects of adjuvant chemotherapy in patients with EBC.