Resistance exercise training in patients with genitourinary cancers to mitigate treatment-related skeletal muscle loss.

The use of targeted therapies in patients with genitourinary malignancies has significantly improved outcomes. For example, androgen receptor (AR) pathway inhibitors have improved outcomes for patients with prostate cancer, and antiangiogenic agents have improved outcomes for those with kidney cancer. However, these advances have been accompanied by musculoskeletal side effects that manifest as physical dysfunction. Although the effects of androgen deprivation therapy on skeletal muscle are well-known, an additional concern is that the muscle loss associated with these newer drugs-especially AR pathway inhibitors-may result in insulin resistance and metabolic syndrome, thus increasing the risk for cardiovascular events and diabetes. Antiangiogenic agents also may cause muscle loss, although this has been poorly described in the literature. As these targeted therapies begin to be used in the earlier stages of treatment, there will be a critical need to prevent treatment-related toxicities with nonpharmacologic interventions. Over the past decade, exercise training has emerged as a novel nonpharmacologic adjunctive method to address toxicities resulting from these targeted therapies. Despite numerous studies in patients with prostate cancer, there remains a large gap in our knowledge of the true efficacy of exercise therapy, as well as the best way to prescribe exercise programs. Here, we suggest that the central role of skeletal muscle in the development of side effects of AR pathway inhibitors and antiangiogenic agents may unlock a number of unique opportunities to study how exercise prescriptions can be used more effectively. Resistance training may be a particularly important modality.