Subcutaneous fat index holds prognostic value in castration-resistant prostate cancer
Subcutaneous fat index (SFI) shows utility in predicting survival in castration-resistant prostate cancer (CRPC), according to a study. Specifically, patients with higher SFI appear to have higher rates of radiographic progression-free survival (RFS) and cancer-specific survival (CSS) than those with lower SFI.
Researchers examined the medical records of 282 consecutive patients who were diagnosed with CRPC between 2009 and 2017. SFI, visceral fat index and skeletal muscle index at CRPC diagnosis were determined using computed tomography data.
Survival analyses for all body composition parameters, which were dichotomized at 39.9 cm2/m2 (SFI), 58 cm2/m2 (visceral fat index) and 52.4 cm2/m2 (skeletal muscle index).
Independent predictors of CSS at CRPC diagnosis included prostate-specific antigen levels, Gleason score ≥8, performance status, shorter period from androgen-deprivation therapy to CRPC and SFI <39.9 cm2/m2.
During the median follow-up of 16.0 months, the number of docetaxel cycles were higher in patients with SFI ≥39.9 cm2/m2 than in those with SFI <39.9 cm2/m2. More importantly, patients with higher SFI had more favourable 1-year RFS (p=0.009) and 2-year CSS (p=0.021).
The present data show that SFI determined via computed tomography data may be used as a useful objective prognostic factor for discussing therapeutic options for CRPC patients, researchers said.
However, more work is needed to define the roles of each body composition parameter in relation to pharmacokinetics and oncological outcome in CRPC, they added.