INTRODUCTION

Changes in body composition (BC) are associated with outcomes in colorectal cancer (CRC), with adverse features such as sarcopenia, myosteatosis, and excess adiposity linked to the systemic inflammatory response (SIR). Whilst ethnic differences in BC have been identified in healthy populations, little is known about how ethnicity influences BC and SIR in patients with CRC.

This study is aimed at assessing the impact of ethnicity on preoperative BC and SIR in patients undergoing surgery for CRC.

METHODS

A multivariate analysis was conducted on a prospectively collected database of CRC patients treated between May 2007 and January 2017. Retrospective augmentation of the dataset included CT-derived BC data and inflammatory markers.

BC was assessed at the third lumbar vertebra using Slice-O-Matic v5.0 with the ABACS L3 plug-in. Predefined thresholds were applied to classify sarcopenia, myosteatosis, visceral obesity (VO), and sarcopenic obesity (SO).

SIR was defined using clinically relevant cut-offs: neutrophil-to-lymphocyte ratio (NLR) > 3, platelet-to-lymphocyte ratio (PLR) > 150, and modified Glasgow Prognostic Score (mGPS) > 0. Ethnicity was recorded using the UK Office for National Statistics 2001 coding and categorised as White (WBB), Black or Black British (BBB), Asian or Asian British (AAB), or Other.

WBB served as the reference group for all comparisons.

RESULTS

A total of 776 patients were included in the final analysis (56% male; median age 69 years, IQR 60-78). Compared to WBB, BBB patients were significantly less likely to be sarcopenic (OR 0.35, 95% CI 0.194-0.624, p = 0.0001), whilst AAB patients were more likely to be sarcopenic (OR 2.02, 95% CI 1.26-3.24, p = 0.003).

BBB patients were also significantly less likely to be myosteatotic (OR 0.39, 95% CI 0.21-0.73, p = 0.003). AAB patients showed a trend toward lower BMI-defined obesity (OR 0.58, 95% CI 0.32-1.04, p = 0.067).

No significant ethnic differences were observed for VO or SO. With respect to inflammation, AAB and BBB patients were significantly less likely to exhibit an NLR > 3 (OR 0.34, 95% CI 0.20-0.56, p = 0.0001 and OR 0.35, 95% CI 0.17-0.74, p = 0.006 respectively).

AAB patients were also significantly less likely to have a PLR > 150 (OR 0.57, 95% CI 0.36-0.92, p = 0.021). No significant association was found between ethnicity and mGPS.

CONCLUSION

Ethnicity significantly influences body composition and systemic inflammation in patients with CRC.

These findings challenge previous models that have not accounted for ethnic variation and highlight the need for ethnicity to be considered in both prognostic modelling and personalised supportive care. Future studies should explore the relationship between BC, inflammation, and oncological outcomes within individual ethnic groups to inform tailored interventions and risk stratification strategies.