Cancer Patients Typically Have Increased Interleukin-6 Levels

June 26, 2006

June 26, 2006 (Atlanta) — Proinflammatory cytokines have been linked to depression, and researchers theorize that the spike in interleukin-6 levels seen in many cancer patients may explain in part why so many battle with mood disorders and cognitive dysfunction. The findings were presented at the recent 42nd annual meeting of the American Society of Clinical Oncology.

"Depression was associated with a significant higher median interleukin-6 level — 14.8 vs 3.7 pg/mL; P < .001," reports the group, led by Christian Jehn, MD, from Charité Campus Mitte in Berlin, Germany. "For cognitive function, only long-term memory was significantly reduced in depression ( P = .01)."

The researchers looked at 55 patients with metastatic cancer assessed by the hospital anxiety and depression scale. Slightly more than half the cohort was diagnosed as having depression according to Diagnostic and Statistical Manual of Mental Disorders ( DSM-IV) criteria. Jehn and colleagues observed no significant differences in mean age or Karnofsky index between patients with and without depression. The researchers also assessed cognitive function using the auditory verbal learning test.

In addition to increased proinflammatory cytokines, depression has been linked to decreased brain-derived neurotrophic factor levels. But the researchers found no difference in neurotrophic factor levels between the 2 groups in this study ( P = .164). They did, however, observe correlations between hospital anxiety and depression scale and interleukin-6 ( r = 4.11; P = .002). They also found associations between interleukin-6 levels and neurotrophic factor levels ( r = -0.42; P = .001) and neurotrophic factor levels and long-term memory ( r = 0.48; P = .02).

Is Depression Under Diagnosed?

In a separate presentation at the meeting, another group of researchers assessed the burden of depression, anxiety, and social distress in a sample of cancer patients at a university center. They wanted to determine whether, despite an active referral program, an unmet need for psychosocial services remains.

They looked at more than 180 patients and found that mental health distress was common. A total of 34% of patients met criteria for referral to psychological or psychiatric services. Led by Caroline Doebbeling, MD, from Indiana University in Indianapolis, the group developed a survey composed of the memorial distress thermometer, specific social work needs, and the depression and anxiety modules from the patient health questionnaire.

They administered the survey to patients presenting for either referral visits or ongoing cancer treatment for a 4-month period. The mean patient health questionnaire depression score was 4.7, with moderate to severe depression in 13%. Symptoms of generalized anxiety were also common, with a mean score of 5.0.

Most of the cohort — 78% — reported at least some distress. A total of 46% were more seriously troubled, scoring 4 or higher on the memorial distress thermometer.

Social Work Needs
Areas of Concern to Patients
Helping children cope with parental illness
Pharmaceutical expenses
Insurance assistance
Discussing illness with spouse
Lodging during treatment

"In people receiving cancer care, previously unknown distress, social work needs, depression, and anxiety were common," Doebbeling reports. "The burden of symptoms resulted in a markedly increased need for psychosocial services."

The researchers recommend routine screening and more integration of psychosocial services with cancer treatment.

ASCO 42nd Annual Meeting: Abstracts 8632, 8633. Presented June 3, 2006.


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