Prognostic Value of Body Fat Density in Colorectal Cancer Adjuvant Treatment: A Retrospective Cohort Study

Adipose tissue radiodensity has emerged as a prognostic biomarker in oncology. This study aimed to assess its prognostic value in colorectal cancer (CRC) patients receiving adjuvant therapy. Body composition was quantified by computed tomography, with visceral (VAT_d) and subcutaneous (SAT_d) adipose tissue radiodensity measured in Hounsfield units and categorized into tertiles, where higher tertiles indicated lower fat proportion, whereas lower tertiles higher fat proportion. The primary endpoint was 5-year overall survival. Stage III disease (HR 5.54, 95% CI: 1.64-18.70), recurrence or metastasis (HR 4.16, 95% CI: 2.39-7.24), and elevated systemic inflammation response index (HR 2.42, 95% CI: 1.55-3.76) were associated with reduced survival. Conversely, the second VAT_d tertile (HR 0.56, 95% CI: 0.33-0.94), adjuvant chemotherapy (HR 0.43, 95% CI: 0.22-0.84), and chemoradiotherapy (HR:0.45, 95% CI: 0.21-0.93) independently predicted improved outcomes. Higher tertiles of SAT_d and VAT_d negatively impacted the beneficial prognosis of adjuvant therapy. However, patients with intermediate SAT_d experienced better protective effects from chemotherapy or chemoradiotherapy (HR 0.17, 95% CI: 0.06-0.49; HR 0.26, 95% CI: 0.08-0.85, respectively). These findings indicate that intermediate VAT_d confers survival advantage, while elevated SAT_d may attenuate treatment efficacy, reinforcing adipose radiodensity as a clinically relevant prognostic marker in CRC.