Sarcopenia in ovarian cancer: Identifying changes in muscle quantity and quality during treatment of advanced disease (214)

Abstract

<b>Objectives:</b> Sarcopenia, a loss of muscle mass and function, is a risk factor for decreased survival in advanced epithelial ovarian cancer (EOC). Little is known about the effect of treatment for EOC on sarcopenia and how this relates to outcomes. We aimed to determine the change in sarcopenia measures over the course of primary EOC treatment and how this impacts overall survival. <b>Methods:</b> We utilized an institutional EOC surgical database to identify stage IIIC or IV EOC patients who received primary debulking surgery (PDS) and adjuvant platinum-based chemotherapy between 2006-2016. Patients were included if they underwent at least five cycles of adjuvant chemotherapy and had CT scans available both before PDS (pre) and near completion of six cycles of adjuvant chemotherapy (post). Patient CT scans were analyzed for body composition measures, including skeletal muscle area (SMA), skeletal muscle attenuation (SMD), and skeletal muscle index (SMI), defined as SMA normalized for patient height. Change in muscle quality (SMD) over muscle quantity (SMI) was evaluated by the ratio of SMD/SMI. The percent change ([post – pre] x100/pre) in body composition measures over time were analyzed for association with death. <b>Results:</b> Among 109 patients included in the analysis (mean age, 62.6 years), the majority of patients received 5-6 cycles of adjuvant chemotherapy (83%). The median time between pre- and post-CT scans was 188 days (IQR: 175 to 211 days). Based on SMI cutoff of <39 cm²/m², almost half of the patients (50/109; 45.9%) were sarcopenic at some point during their treatment, including 27 (24.8%) who were sarcopenic on both scans and 23 (21.1%) who became sarcopenic at post-treatment scan. We observed a statistically significant decrease in muscle quantity (mean±SD percent change in SMI, -4.4±9.2; p<0.001) and a non-significant increase in muscle quality (mean±SD percent change in SMD, 6.3±25.1; p=0.28) following treatment. Given these findings, the density of muscle per unit area (SMD/SMI) was analyzed. On average, SMD/SMI increased from pre- to post-treatment CT scans, from 0.83±0.26 to 0.89±0.25 HU*m²/cm², translating to a percent increase of 12.2±30.0 (p<0.001). An increase in the percent change of SMD/SMI over the course of treatment was significantly associated with an increased risk of death (Figure A). In particular, the median OS was 3.6 years in women with percent change in SMD/SMI >10%, 4.8 years in those with percent change between ±10%, and 6.2 years for those with > -10% change (Figure B, p=0.017). There was no significant association observed when evaluating SMI and SMD.Fig. 1 <b>Conclusions:</b> Patients who underwent curative-intent PDS and adjuvant chemotherapy had changes in sarcopenia measures following treatment. Those with an increase in muscle density per unit area following treatment had worse survival; this hypothesis-generating finding illustrates the need for continued research evaluating how patient factors and tumor biology influence sarcopenia and subsequent outcomes in this high-risk group.