Diagnostic criteria of cancer cachexia: relation to quality of life, exercise capacity and survival in unselected palliative care patients.

PURPOSE: Cachexia is associated with adverse outcomes. There is limited information on the impact of different diagnostic criteria of cachexia on patient centered outcomes.
METHODS: We compared the prevalence of reduced quality of life (QoL), physical function and survival in palliative care cancer patients classified by different cachexia criteria. Four hundred and five patients with advanced cancer were included. Cachexia criteria were BMI, weight loss, fatigue, Karnofsky performance score, low handgrip strength, lean tissue depletion (DXA or arm muscle circumference) and abnormal biochemistry (inflammation, anemia or low serum albumin). QoL was assessed with a cancer specific questionnaire (EORTC QLQ-C30) and classified by cluster analysis. Dietary intake was obtained from a 4-day food record. Physical function was measured on a treadmill.
RESULTS: Weight loss >2%, BMI <20, fatigue and CRP >10 mg/L were associated with adverse QoL, function and symptoms (odds ratios: 2.1, 2.9, 4.0 and 3.1 respectively, P < 0.05 for all). Fatigue, low grip strength and markers of systemic inflammation were associated with short walking distance (P < 0.05). Weight loss > 2%, fatigue, CRP > 10 mg/L and S-albumin < 32 g/L were associated with shorter survival (hazard ratios: 1.4, 1.6, 2.2 and 2.0 respectively, P < 0.05 for all). The prevalence of cachexia diagnosis varied from 12 to 85% using different definitions.
CONCLUSIONS: Weight loss, fatigue and markers of systemic inflammation were most strongly and consistently associated with adverse QoL, reduced functional abilities, more symptoms and shorter survival. The prevalence of cachexia using different definitions varied widely; indicating a need to further explore and validate diagnostic criteria for cancer cachexia.