Among lung cancer patients, objective physical function declines with increasing fatigue, according to researchers in Scotland. Fatigue, in turn, is related to mental stress rather than physical factors, they found.
“Functional disability is reported frequently in fatigued cancer patients, but little is known about the correlation between fatigue and objective physical function,” Dr. Duncan J. F. Brown, of St. Columba’s Hospice in Edinburgh, UK, and colleagues explain in the January 15th issue of Cancer. “In addition, from previous work, the systemic inflammatory response and psychological distress appear to be related to fatigue,” they point out.The researchers examined the relationship between fatigue, physical function, the systemic inflammatory response, and psychological distress in 38 subjects with advanced lung cancer and 15 matched healthy controls. The participants completed the Functional Assessment of Chronic Illness Therapy-Fatigue scale, a visual analogue weakness score, and the Hospital Anxiety and Depression (HAD) scale. In addition, hemoglobin concentrations, white blood cell count, body composition, Karnofsky performance status (KPS), grip strength, and chair-rise time were also assessed.Cancer patients weighed significantly less than control patients, and had lower albumin and hemoglobin concentrations. White blood cell counts and CRP concentrations were significantly elevated in patients with cancer. Compared with the control group, cancer patients had lower KPS, lower hand-grip strength, and performed worse in the chair-rise test.Levels of fatigue, weakness, and psychological distress were significantly greater (p < 0.001) in cancer patients than in controls. "With increasing fatigue, there were lower KPS scores (p = 0.001), slower chair-rise times (p < 0.01), higher weakness scores (p = 0.001), and higher HAD scale scores (p = 0.001)," Dr. Brown's team explains. "In a multiple regression analysis of these significant factors, only KPS scores, weakness scores, and HAD scale scores were correlated independently with fatigue (p < 0.001)." In other words, they say, "Fatigue is not a result primarily of weight loss or anemia." While other etiologies are elusive, it is "related to performance status and psychological distress."(Source: Cancer 2005;103:377-382: Reuters Health: Oncolink: February 2005.)