Article Text

Download PDFPDF

45 Body composition as a predictive and prognostic biomarker in advanced urothelial carcinoma (UC) patients treated with immune checkpoint inhibitors (ICI)
  1. Dylan Martini1,
  2. Julie Shabto1,
  3. Subir Goyal2,
  4. Yuan Liu2,
  5. T Anders Olsen1,
  6. Sean Evans1,
  7. Benjamin Magod1,
  8. Deepak Ravindranathan1,
  9. Jacqueline Brown1,
  10. Lauren Yantorni3,
  11. Greta Russler3,
  12. Sarah Caulfield1,
  13. Jamie Goldman1,
  14. Bassel Nazha1,
  15. Shreyas Joshi1,
  16. Haydn Kissick1,
  17. Kenneth Ogan1,
  18. Wayne Harris1,
  19. Omer Kucuk1,
  20. Bradley Carthon1,
  21. Viraj Master1 and
  22. Mehmet Bilen1
  1. 1Emory University School of Medicine, Atlanta, GA, USA
  2. 2Emory University, Atlanta, GA, USA
  3. 3Winship Cancer Institute of Emory University, Atlanta, GA, USA


Background Several immune checkpoint inhibitors (ICI) have been approved for the treatment of advanced urothelial carcinoma (UC). There are limited predictive biomarkers for UC patients treated with ICI. In this study, we investigated the association between body composition and clinical outcomes in ICI-treated advanced UC patients.

Methods We conducted a retrospective analysis of 70 ICI-treated advanced UC patients at Winship Cancer Institute from 2015–2020. Inclusion criteria was available computed tomography (CT) scans within 2 months of ICI-initiation. Baseline CT images were collected at mid-L3 and muscle and fat compartments were segmented using SliceOMatic v5.0 (TomoVision). The density of subcutaneous fat, inter-muscular fat, visceral fat, and skeletal muscle (SM) were measured and converted to indices by dividing by height(m)2 (SFI, IFI, VFI and SMI, respectively). Attenuated SM mean (Hounsfield Units) was also collected. Myosteatosis was calculated by IFI/SMI*100%. Gender-specific optimal cuts were used to dichotomize patients as high or low for each variable using OS as the primary outcome. A prognostic body composition risk score was created based on the beta coefficient from the multivariable Cox model (MVA) following best-subset variable selection. Our body composite risk score was SMI + 2*SM mean + VFI and patients were categorized as high (0–1), intermediate (2–3), or low-risk (4). Comparison of OS and PFS between the risk groups was performed via Kaplan-Meier method and Log-rank test. Concordance statistics (C-statistics) were used to quantify the discriminatory magnitude of the predictive model.

Results Most patients (70%) were male and more than one-quarter (26%) had an ECOG PS ≥ 2. The majority received ICI in the second (46%) or third-line (21%) setting. Body composite poor-risk patients had significantly shorter OS (HR: 6.18, p<0.001), PFS (HR: 5.91, p<0.001), and lower chance at CB (OR: 0.02, p=0.004) compared to low-risk group in MVA (table 1). Patients with low myosteatosis had significantly longer OS (HR: 0.35, p=0.002), PFS (HR: 0.32, p<0.001), and higher chance at CB (OR: 20.47, p=0.034) compared to high myosteatosis patients in MVA. The C-statistics for our body composition risk group and myosteatosis analyses were higher than BMI for all clinical outcomes (table 2). High and intermediate-risk patients had significantly shorter OS and PFS compared to low-risk patients per Kaplan-Meier estimation (figure 1).

Abstract 45 Table 1

MVA* of association between risk groups and myosteatosis with clinical outcomes

Abstract 45 Table 2

Comparison of C-statistics between body composition risk groups, myosteatosis and BMI

Abstract 45 Figure 1

Kaplan-Meier curves of association between body composition risk groups and overall survival (OS, top panel) and progression-free survival (PFS, bottom panel)

Conclusions Body composition variables such as SMI, SM mean, VFI and myosteatosis may be predictive of clinical outcomes in ICI-treated advanced UC patients. Larger, prospective studies are warranted to validate this hypothesis-generating data.

Acknowledgements Research reported in this publication was supported in part by the Biostatistics and Bioinformatics Shared Resource of Winship Cancer Institute of Emory University and NIH/NCI under award number P30CA138292. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Trial Registration Not applicable

Ethics Approval This retrospective study was approved by the Emory University Institutional Review Board.

Consent Not applicable

References Not applicable

This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.