Abstract P1-08-04: The impact of sarcopenia and sarcopenic obesity detected by bioelectrical impedance analysis in patients with early breast cancer
Authors: Aleixo Gabriel F. P. , Wei Wei , Valente Sephanie A , Moore Halle CF 
Published: March 2022

Background: Low muscle mass, known as sarcopenia, is associated with chemotherapy toxicity and reduced survival in women with breast cancer (BC). Sarcopenic obesity, a process in which patients lose muscle mass and increase body adipose mass, is associated with multiple comorbidities and worse outcomes in BC. Most studies to date used Computer Tomography (CT) to obtain the parameters necessary to calculate sarcopenia and sarcopenic obesity. However, CT scans are not routinely performed in women with early BC. Bioelectrical impedance analysis (BIA) is a noninvasive, easy to use tool to assess multiple body composition parameters; it does not expose patients to radiation, and gives results instantaneously. BIA can assess for both sarcopenia and sarcopenic obesity. Our study aims to evaluate the impact of BIA assessed sarcopenia and sarcopenic obesity on treatment-related adverse events in patients with early-stage BC who received (neo)adjuvant chemotherapy.Methods: From a cohort of 713 patients with stage I-III breast cancer who had undergone BIA analyses around the time of their initial cancer diagnosis and treatment, 361 were treated with chemotherapy. BIA was used to generate the Skeletal Muscle Area (SMA), Fat Mass (FM) and Fat-Free Mass (FFM). Skeletal Muscle Index (SMI) was calculated to assess for sarcopenia: SMI= (SMA, cm2)/(patient height, m2). Patients were divided into normal (SMI &gt; 6.75 kg/m2), moderate sarcopenia (SMI between 6.75 and 5.76 kg/m2), and severe sarcopenia (SMI &lt;5.75 kg/m2). Sarcopenic obesity is suggested by an elevated ratio of FM to FFM. Since there is no predefined cut-point for sarcopenic obesity, we compared patients with FM/FFM at or above the median to those below the median. Fisher's exact test was performed to associate patient characteristics and toxicity outcomes with sarcopenia and sarcopenic obesity status.Results: Median age was 60 years old (range: 26 to 88). Moderate Sarcopenia was present in 28% and severe sarcopenia in 6% of patients. The presence of sarcopenia was associated with higher rates of early chemotherapy termination at 17% and 38% among those with moderate or severe sarcopenia compared with 8% of those without sarcopenia (p=0.0006). Hospitalizations related to chemotherapy were higher in patients with moderate (17%) and severe sarcopenia (15%) compared with those without sarcopenia (8%; p=0.02). In addition, grade 3-4 neuropathy was more common in patients with moderate or severe sarcopenia (38% and 12%) compared to those without sarcopenia (9%; p=0.006). Similarly, patients with sarcopenic obesity had a significantly higher chance of early chemotherapy termination (16% versus 7%; p=0.004), hospitalization related to chemotherapy (15% versus 7%; p=0.008), and grade 3-4 neuropathy (17% versus 6%; p=0.0004). No significant differences were observed in rates of dose delay or dose reduction between the groups.Conclusion: Patients with early-stage breast cancer and baseline evidence of BIA assessed sarcopenia or sarcopenic obesity had poorer tolerance of (neo)adjuvant chemotherapy. Future studies should address whether body composition-based dosing strategies can improve patient outcomes.

Citation Format: Gabriel F. P. Aleixo, Wei Wei, Sephanie A Valente, Halle CF Moore. The impact of sarcopenia and sarcopenic obesity detected by bioelectrical impedance analysis in patients with early breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-08-04.