Prognostic Impact of Sarcopenia in Patients with Metastatic Hormone-Sensitive Prostate Cancer

SIMPLE SUMMARY: As sarcopenia is recognized as a poor prognostic factor in various type of cancers, we hypothesized that sarcopenia may also have adverse impact in patients with metastatic hormone-sensitive prostate cancer (mHSPC). In this study, we found that sarcopenia is an independent prognostic factor for poor failure-free survival and time to prostate-specific antigen progression in patients with mHSPC who receive early docetaxel or abiraterone acetate treatment. In addition, we performed RNA sequencing of primary tumors to further understand the biological perspective of the presence of sarcopenia in mHSPC. Transcriptomic differences were found between primary tumors with and without sarcopenia, which may have a potential to link between sarcopenia and poor clinical outcomes in these patients. ABSTRACT: The clinical value of sarcopenia has not been determined yet in metastatic hormone-sensitive prostate cancer (mHSPC). We retrospectively evaluated data of 70 consecutive patients with mHSPC receiving treatment with either early docetaxel (n = 42) or abiraterone acetate (n = 28) between July 2018 and April 2021. Skeletal muscle index was calculated from cross-sectional areas of skeletal muscle on baseline computed tomography (CT), defining sarcopenia as a skeletal muscle index of ≤52.4 cm(2)/m(2). Failure-free survival (FFS), radiographic progression-free survival, and time to prostate-specific antigen (PSA) progression were estimated using the Kaplan–Meier method, and differences in survival probability were compared using the log-rank test. Cox proportional hazards regression analysis was conducted to identify the predictors of clinical outcomes. Patients with sarcopenia (n = 47) had shorter FFS than those without sarcopenia (n = 23) (median, 20.1 months vs. not reached; log-rank p < 0.001). Sarcopenia was independently associated with shorter FFS (hazard ratio (HR), 6.69; 95% confidence interval (CI), 1.57–28.49; p = 0.010) and time to PSA progression (HR, 12.91; 95% CI, 1.08–153.85; p = 0.043). In conclusion, sarcopenia is an independent prognostic factor for poor FFS and time to PSA progression in patients with mHSPC who receive early docetaxel or abiraterone acetate treatment.