A longitudinal study of muscle strength and function in patients with cancer cachexia.

Purpose: Patients with cancer frequently experience an involuntary loss of weight (in particular loss of muscle mass), defined as cachexia, with profound implications for independence and quality of life. The rate at which such patients' physical performance declines has not been well established. The aim of this study was to determine the change in muscle strength and function over 8 weeks in patients with already established cancer cachexia, to help inform the design and duration of physical activity interventions applicable to this patient group.

Methods: Patients with thoracic and gastrointestinal cancer and with unintentional weight loss of > 5% in 6 months or BMI < 20 plus 2% weight loss were included. Physical and functional assessments (baseline, 4 weeks, 8 weeks) included isometric quadriceps and hamstring strength, handgrip, standing balance, 10-m walk time and timed up and go.

Results: Fifty patients (32 male), mean ± SD age 65 ± 10 years and BMI 24.9 ± 4.3 kg/m, were recruited. Thoracic cancer patients had lower muscle strength and function (p < 0.05). Despite notable attrition, in patients who completed all assessments (8 thoracic and 12 gastrointestinal), there was little change in performance over 8 weeks (p > 0.05). Baseline variables did not differentiate between completers and non-completers (p > 0.05).

Conclusions: More than a third of patients with established cancer cachexia in our study were stable over 8 weeks, suggesting a subgroup who may benefit from targeted interventions of reasonable duration. Better understanding the physical performance parameters which characterise and differentiate these patients has important clinical implications for cancer multidisciplinary team practice.