Improving analysis of sexual dimorphism in body composition dynamics in the oncology setting: A scoping review.

Background And Aims: Chemotherapy treatments induce loss of skeletal muscle and adipose tissue each of which are important prognostic indicators after a cancer diagnosis. Males and females may respond differently to drugs used to treat cancer. Given the high degree of heterogeneity in the literature, the objective of this scoping review is to evaluate the methodological variability in reporting of muscle and adipose tissue changes comparing males and females during cancer-directed treatment.

Methods: Relevant databases were searched for papers reporting longitudinal CT based body composition changes separately for males and females in solid tumors.

Results: Of the 29 studies that met inclusion criteria, 22 were retrospective and 7 were prospective. The majority of studies reported on gastrointestinal cancers [n=24]. Among collective participants (n= 5139), 32% were females. Females were under represented in half the studies. For 21/29 studies, baseline characteristics were combined for males and females, hindering the ability to understand the effect of disease stage, chemotherapy type and co-morbidities on muscle and fat changes experienced by each sex. Multiple chemotherapy regimens were combined (n=24) and not reported in a sex-specific way (n=26).

Conclusion: While the literature reporting body composition changes during cancer treatment is abundant, study design and reporting is problematic and precludes metaanalysis. Disproportionate numbers of males and females, marked heterogeneity in cancer types and chemotherapy regimens evaluated within a single study collectively pose challenges in analysing the impact of specific chemotherapy regimens on muscle and adipose change by sex. Strategies to standardize this set of literature in a sex specific way are required to improve evidence synthesis.