Visceral and subcutaneous fat attenuation as prognostic indicators of survival in castration resistant prostate cancer

Abstract

Background

While previous studies have examined the link between body fat mass and prognosis in patients with castration-resistant prostate cancer (CRPC), limited evidence exists regarding the prognostic role of specific fat characteristics. We aimed to analyze the relationship between body fat characteristics and cancer-specific survival (CSS) in patients newly diagnosed with CRPC.

Methods

Subcutaneous fat attenuation (SAT-HU) and visceral fat attenuation (VAT-HU) were quantified using Hounsfield units (HU) on computed tomography scans at the time of CRPC diagnosis. Average HU values were measured at the L3 vertebra. Patients were stratified into quartiles by SAT-HU and VAT-HU values, and survival outcomes were estimated for each subgroup.

Results

Among the 420 patients studied, 340 (81.0%) died from prostate cancer (PC), with a median CSS of 21 months. SAT-HU quartiles were as follows: Q1 (−121.2 to −108.2 HU), Q2 (−108.1 to −102.2 HU), Q3 (−102.1 to −96.0 HU), and Q4 (−95.9 to −52.6 HU). VAT-HU quartiles were as follows: Q1 (−112.6 to −100.9 HU), Q2 (−100.8 to −96.3 HU), Q3 (−96.2 to −89.8 HU), and Q4 (−89.7 to −57.2 HU). The proportion of patients receiving both androgen receptor pathway inhibitor and chemotherapy was the highest in Q1, while chemotherapy alone was the most common in Q4. Median CSS by quartile were Q1: 44, Q2: 24, Q3: 20, and Q4: 12 months for SAT-HU, and Q1: 39, Q2: 29, Q3: 19, and Q4: 13 months for VAT-HU (both P < 0.001). Multivariate analysis showed that higher SAT-HU (hazard ratio [HR] 1.686, P = 0.004) and VAT-HU (HR 1.850, P < 0.001) independently predicted poorer CSS.

Conclusions

Higher SAT-HU and VAT-HU were associated with worse CSS in patients with CRPC. These findings highlight the potential of fat tissue attenuation as a valuable imaging biomarker for prognosis in CRPC, warranting further studies into its clinical application.