Body Composition and Chemotherapy Toxicities in Women Undergoing Treatment for Breast Cancer

Purpose: This thesis provides a comprehensive overview of the impact of body composition on chemotherapy toxicities for women undergoing treatment for breast cancer. Breast cancer is the most diagnosed cancer and the leading cause of cancer death in women globally. Chemotherapy remains a common treatment option, however, current chemotherapy dosage calculations are determined by body surface area, which does not account for differences in an individual’s body composition. Systematic Review: A systematic review of studies from the last 10 years was completed which highlights the significance of body composition, particularly sarcopenia, in chemotherapy tolerance and overall survival. This review suggests body composition to be an important factor in predicting the severity of chemotherapy toxicities during treatment for breast cancer. Although significant findings were reported by many of the papers included, their heterogeneity made it difficult to make comparisons between individual studies, supporting the need for further prospective studies. This would allow for more robust, pre-determined data collection, leading to a better understanding of the implications of body composition on toxicities, and the possible benefits of using body composition to individualise chemotherapy dosing. Pilot Study: A prospective pilot study was conducted to investigate the influence of different body composition factors and the risk of experiencing chemotherapy toxicities during treatment for non-metastatic (stage I-III) breast cancer. While most previous studies relied on computed tomography (CT) scans for the assessment of body composition, this study utilised bioimpedance spectroscopy (BIS) technology, allowing measurements to be implemented in a clinical setting and without exposure to radiation as with CT. Although no significant findings were identified in this pilot study, likely due to the small sample size, it highlights the potential value of implementing BIS technology to assess body composition for all individuals prior to, and throughout their chemotherapy treatment and justifies future prospective studies with larger sample sizes to further examine this relationship. Implications: Complications arising from chemotherapy can lead to an inability to complete the planned treatment, potentially leading to compromised survival outcomes. Improved knowledge about the role of body composition on chemotherapy toxicities may give rise to a more reliable way of identifying those at risk. Furthermore, this may lead to the development of individualised chemotherapy dosage calculations based on body composition, to help mitigate this risk.<p></p>