Association of muscle mass with survival after radical prostatectomy in patients with prostate cancer.

Although muscle mass has been associated with survival in patients with various types of solid tumors, the relationship between muscle mass and survival in prostate cancer patients remains unclear. This study retrospectively investigated the association of muscle mass with survival after radical prostatectomy in patients with prostate cancer.

Records of 2,042 patients who underwent radical prostatectomy for prostate cancer between 1998 and 2013 were reviewed. Muscle mass was evaluated by measuring psoas muscle index (PMI) on preoperative computed tomography images.

Ten-year distant metastasis-free survival rates in the lowest, second, third, and highest PMI quartiles were 72.5%, 83.8%, 92.3%, and 93.7%, respectively (p<0.001); 10-year cancer-specific survival rates were 85.7%, 92.1%, 96.8%, and 97.6%, respectively (p<0.001); and 10-year overall survival rates were 74.5%, 79.6%, 89.8%, and 90.6%, respectively (p<0.001). PMI was positively correlated with body mass index (BMI), serum concentrations of insulin-like growth factor (IGF)-binding protein-3 and bioavailable testosterone, and inversely correlated with age, serum concentration of sex hormone-binding globulin and neutrophil-lymphocyte ratio. In multivariable analysis, PMI was independently associated with increased risks of biochemical recurrence, distant metastasis, cancer-specific death and overall death.

Low muscle mass may be associated with increased risks of recurrence and mortality in patients who undergo radical prostatectomy for prostate cancer, regardless of BMI. Large-scale prospective studies are warranted.

The Journal of urology. 2019 Mar 27 [Epub ahead of print]

Sahyun Pak, Seo Young Park, Teak Jun Shin, Dalsan You, In Gab Jeong, Jun Hyuk Hong, Choung-Soo Kim, Hanjong Ahn

Department of Urology, Center for Urological Cancer, National Cancer Center , Goyang , Korea ., Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine , Seoul , Korea ., Department of Urology, Keimyung University School of Medicine , Daegu , Korea ., Department of Urology, University of Ulsan College of Medicine, Asan Medical Center , Seoul , Korea .