Purpose:Poor body composition metrics (BCM) are associated with inferior cancer outcomes; however, in early breast cancer (EBC) there is a paucity of evidence regarding BCM's impact on toxicities. This study investigates associations between BCM and treatment-related toxicity in EBC patients receiving anthracyclines-taxane based chemotherapy. Experimental Design: Pretreatment computerized tomography (CT) images were evaluated for skeletal muscle area (SMA), density (SMD), and fat tissue at the 3rd lumbar vertebrae. Skeletal muscle index (SMI) (SMA/height2) and skeletal muscle gauge (SMG=SMI x SMD) were also calculated. Relative risks (RR) are reported for associations between body composition measures and toxicity outcomes, after adjustment for age and body surface area (BSA). Results:BCM were calculated for 151 patients with EBC (median age 49, range 23 to 75). Fifty patients (33%) developed grade 3 or 4 toxicity, which was significantly higher in those with low SMI (RR=1.29, p=0.002), low SMG (RR=1.09, p=0.01), and low LBM (RR=1.48, p=.002). ROC analysis showed the SMG measure to be the best predictor of grade 3 and 4 toxicity. Dividing SMG into tertiles showed toxicity rates of 46%, and 22% for lowest versus highest tertile, respectively (p=0.005). After adjusting for age and BSA, low SMG (<1475 units) was significantly associated with hematological (RR=2.12, p=0.02), gastrointestinal grade 3-4 toxicities (RR=6.49, p=0.02), and hospitalizations (RR=1.91, p=0.05). Conclusions:Poor BCM are significantly associated with increased treatment-related toxicities. Further studies are needed to investigate how these metrics can be used to more precisely dose chemotherapy to reduce treatment related toxicity while maintaining efficacy.
- Received September 20, 2016.
- Revision received January 18, 2017.
- Accepted January 25, 2017.
- Copyright ©2017, American Association for Cancer Research.