Mapping Physical Fitness Assessments in Interventional Research Among Breast Cancer Survivors: A Scoping Review

Background/Objectives: Breast cancer survivors differ from non-cancer populations in that cancer treatment commonly induces declines in physical fitness (PF) that are relevant to treatment tolerance, recovery, and survivorship outcomes. However, PF assessment methods vary widely across interventional studies. This scoping review aimed to map and characterize objective PF assessments used in interventional research among breast cancer survivors. Methods: Following PRISMA-ScR guidelines, PubMed, MEDLINE, EMBASE, Web of Science, KoreaMed, KCI, ClinicalTrials.gov, and Google Scholar were searched through November 2024. Interventional studies enrolling adult female breast cancer survivors and reporting at least one objectively measured PF outcome were included. Results: Of 9697 records identified, 316 studies met the inclusion criteria. Most interventions were exercise-based (83.2%) and conducted in the post-treatment phase (56.4%). Across the 316 studies, 557 PF domain records were identified because a single study could report more than one PF domain. Muscular strength accounted for the largest proportion of PF domain records (n = 222, 39.9%), followed by cardiorespiratory fitness (n = 190, 34.1%), flexibility (n = 100, 18.0%) and physical function (n = 45, 8.0%). Assessment method records showed that field-based walking test, strength test, shoulder range of motion test and balance tests were commonly used within their respective domain. Substantial heterogeneity in protocols, timing, and reporting limited comparability across studies. Conclusions: PF assessments are widely used in interventional breast cancer survivorship research but remain unevenly distributed across domains and treatment phases. More standardized and clearly reported PF assessment methods are needed to improve comparability and support future survivorship research.