Abstract 669P
Background
In men with mCRPC, prolonged androgen ablation adversely impacts the distribution of adipose tissue and skeletal muscle mass, so body mass index (BMI) may be an imprecise surrogate for body composition in this population. Previous studies in men with mCRPC have suggested that the subcutaneous adipose tissue index (SATi) may influence outcomes on docetaxel, abiraterone, or enzalutamide alone, yet the impact of body composition on chemotherapy combined with maximal androgen ablation is unknown.
Methods
Men with mCRPC uniformly treated on a prospective clinical trial with a combination of abiraterone acetate, apalutamide, carboplatin, and cabazitaxel were included in this post-hoc analysis (NCT02703623). Body composition was assessed at the level of L3 on baseline CT scan at trial registration using Slice-O-Matic version 5.0. Body composition indices were normalized for height (m2). Associations between categorical baseline measures and objective response were tested with chi-square tests, continuous baseline measures were tested with non-parametric Kruskal-Wallis test.
Results
In 58 men with mCRPC, median BMI was 29.2, 68% had sarcopenia, and 25% had sarcopenic obesity. The SATi was strongly correlated with BMI (r=0.79), but there was a weaker correlation between the visceral adipose tissue index (VATi) and BMI (r=0.54). Responders had a significant and meaningfully higher SATi (87.9 vs. 62.7, p=0.01), with a non-significant trend towards higher BMI (30.4 vs. 28.6, p=0.21). Skeletal muscle mass index (46.3 vs. 48.1, p=0.36) and VATi (60.3 vs. 61.5, p=0.73) were similar between responders and non-responders.
Conclusions
In this cohort of men with mCRPC, increasing subcutaneous adiposity was associated with response to chemotherapy combined with maximal androgen ablation, whereas skeletal muscle mass was not. This study establishes a methodological program to more accurately capture body composition and understand its importance for outcomes in men with mCRPC. Ongoing studies are assessing the predictive and prognostic value of these measurements in men with mCRPC.
Clinical trial identification
NCT02703623.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
P. Msaouel: Honoraria (self): Pfizer; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution): Bristol-Myers Squibb; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution): Mirati; Honoraria (self): Exelixis; Research grant/Funding (institution): Takeda; Research grant/Funding (institution): Gateway for Cancer Research. E. Efstathiou: Advisory/Consultancy, Research grant/Funding (institution): Bayer; Advisory/Consultancy, Research grant/Funding (institution): Merck; Advisory/Consultancy, Research grant/Funding (institution): Janssen; Advisory/Consultancy, Research grant/Funding (institution): Pfizer; Advisory/Consultancy, Research grant/Funding (institution): AstraZeneca; Advisory/Consultancy, Research grant/Funding (institution): Oric; Advisory/Consultancy, Research grant/Funding (institution): Astellas; Advisory/Consultancy, Research grant/Funding (institution): Sanofi; Non-remunerated activity/ies, Member of scientific committee: ESMO. A.J. Zurita-Saavedra: Advisory/Consultancy: Bayer; Honoraria (self), Advisory/Consultancy: Pfizer; Advisory/Consultancy: Incyte; Advisory/Consultancy: Biocept; Research grant/Funding (institution): Infinity Pharma; Honoraria (self): McKesson Specialty Health; Honoraria (self): Janssen-Cliag. S-M. Tu: Advisory/Consultancy: Janssen Biotech. J.L. McQuade: Advisory/Consultancy: Roche; Advisory/Consultancy: Bristol-Myers Squibb; Advisory/Consultancy: Merck. D. Fogelman: Shareholder/Stockholder/Stock options, Full/Part-time employment: Merck. S.K. Subudhi: Advisory/Consultancy, Research grant/Funding (institution): Janssen Oncology; Advisory/Consultancy: Amgen; Research grant/Funding (institution), Shareholder/Stockholder/Stock options: Apricity Health; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution), Travel/Accommodation/Expenses: AstraZeneca; Advisory/Consultancy: Bayer; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution), Travel/Accommodation/Expenses: Bristol-Myers Squibb; Advisory/Consultancy: Cancer Now; Honoraria (self), Advisory/Consultancy, Travel/Accommodation/Expenses: Dava Oncology; Honoraria (self), Advisory/Consultancy, Travel/Accommodation/Expenses: Dendreon; Advisory/Consultancy: Exelixis; Advisory/Consultancy: MEDACorp; Advisory/Consultancy: Polaris; Honoraria (self), Travel/Accommodation/Expenses: Parker Institute of Cancer Immunotherapy; Honoraria (self), Travel/Accommodation/Expenses: Society for Immunotherapy of Cancer. A. Aparicio: Research grant/Funding (institution): AstraZeneca; Research grant/Funding (institution): Bristol-Myers Squibb; Research grant/Funding (institution): Emerson Collective; Research grant/Funding (institution): GlaxoSmithKline; Research grant/Funding (institution): Janssen; Research grant/Funding (institution): Sanofi; Advisory/Consultancy: Amgen. All other authors have declared no conflicts of interest.