Further Study Needed of the Role of Ginseng in Combating Fatigue

American ginseng shows promise in decreasing cancer-related fatigue, according to results of a placebo-controlled, double-blind, randomized pilot trial presented during Sunday's Patient Care Oral Abstract Session (Abstract 9001).

However, more research of the herb (Panax quinquefolius ) is needed before investigators can recommend its routine use in patients with cancer, reported Debra Barton, RN, PhD, of the Mayo Clinic, a principal investigator in the

National Cancer Institute-sponsored North Central Cancer Treatment Group (NCCTG) Trial N03CA. The trial was undertaken to determine if there is sufficient indication of fatigue reduction to proceed with a larger study.

Fatigue is a major problem for patients with cancer, yet few therapies, including ginseng, have been subjected to rigorous scientific study, Dr. Barton said.

She and her colleagues studied the effects of American ginseng at three doses: 750, 1,000 and 2,000 mg per day. Eligible patients had had surgery more than 4 weeks earlier, had a life expectancy of 6 months or longer and had reported cancer-related fatigue of at least 4 (on a scale of 0 to 10) for 1 month or longer, with no other known causes or treatments of fatigue. More than 50% of the patients were receiving concurrent chemotherapy. Of the 282 patients initially enrolled, 175 patients completed the study.

Participants were randomly assigned to receive either placebo or Wisconsin ginseng-root capsules twice a day for 8 weeks. Testing showed the capsules had a uniform concentration of ginsenosides. The primary trial endpoint was the Brief Fatigue Inventory (BFI). Other endpoints included the Vitality Subscale of the Short-Form-36 (SF-36); a self-assessment scale of physical, mental, emotional and spiritual well-being; and the patient's global impression of change (perceived benefit).

Clear evidence of benefit for ginseng in the primary study endpoint of the BFI was not seen (see Figure). Values of the area under the curve for improvement in BFI at 8 weeks ranged from 460 in patients in the placebo group to 551 in patients who received ginseng at a dose of 2,000 mg. Patients who received ginseng had more than twice the perceived benefit of feeling moderately to very much better than did those who received a placebo, Dr. Barton reported.

Additionally, American ginseng had a favorable toxicity profile. Most toxicities were grade 1 or 2, and there was no significant difference in toxicity between ginseng and placebo.

“Further study of American ginseng in survivors of cancer is warranted,” Dr. Barton said. “While our results may be just noise, there is too much signal to ignore.”

The investigators hope to begin a larger trial next year, Dr. Barton said in an interview.

Discussant Ian Tannock, MD, PhD, of Princess Margaret Hospital, Canada, noted that progress has been made in this field since the publication of a 2000 study that reported that fatigue is “inevitable, unimportant and untreatable” (Stone P et al. Ann Oncol. 2000;11:971-975 ). Several recent studies have found that fatigue is the second most frequently reported problem in patients with cancer, occurring in more than 50% of patients and lasting as long as 5 years after diagnosis.

Exercise has the greatest scientific evidence of improving fatigue, but it is not an easy option for many patients with cancer-associated fatigue. “We desperately need other treatment measures,” Dr. Tannock said.

However, he recommended that oncologists continue to educate patients who experience fatigue about the importance of exercise. He added that placebos can have positive effects in the short term.

“There is no evidence to support pharmacologic treatment of fatigue from the [study] presented,” Dr. Tannock said.

The NCCTG trial did not address whether patients exercised before or during the study, Dr. Barton said.