The underrecognized role of impaired muscle function in cancer-related fatigue

This timely article by Drs. Davis and Walsh provides a succinct overview of the task-dependent mechanisms that could limit neuromuscular function to result in increased muscle fatigue or decreased muscle endurance. This work has particular importance to cancer survivorship, because such mechanisms could possibly explain part (or all) of the phenomenon of cancer-related fatigue (CRF). Anemia, cachexia, and malnutrition are well-understood consequences of cancer or its treatment that can contribute to CRF, but impaired neuromuscular or muscle function resulting in muscle fatigue has attracted comparatively little attention. This finding is somewhat surprising given that the process (decreased maximal force generation) or consequences (eg, decreased endurance) are readily quantifiable using the standard techniques highlighted by Drs. Davis and Walsh. From a broad perspective, an understanding of muscle or neuromuscular fatigue could provide a mechanistic link that is somewhat lacking in some current models of CRF. For example, it is becoming increasingly accepted that exercise is one of the few effective tools for managing unexplained CRF in the absence of anemia or cachexia. The mechanism of action of exercise could be through preserving muscle strength or endurance by preventing deterioration o