Clinical Assessment and Management of Cancer-Related Fatigue

Modafinil is a non-amphetamine psychostimulant that has been approved for the treatment of narcolepsy. In a trial studying the effect of modafinil on patients receiving docetaxel-based chemotherapy for metastatic breast or prostate cancer, there was a modest but not statistically significant improvement in fatigue scores on the MD Anderson Symptom Inventory compared with placebo. Nausea and vomiting were higher in the modafinil arm than in the placebo arm [86]. Similarly, modafinil was not superior to placebo for CRF in 208 patients with non-squamous cell lung cancer not undergoing chemotherapy or radiation [87]. A placebo effect was also noted in patients with multiple myeloma [88] and patients with primary brain tumors [89]. In a phase 3, multicenter, randomized, placebo-controlled, double-blind clinical trial of modafinil for CRF in 867 patients undergoing chemotherapy, there was a reduction in fatigue only for patients with severe baseline fatigue, with no significant effect on mild to moderate fatigue [90]. In another recent study, modafinil was shown to reduce depressive symptoms only in patients with severe fatigue (BFI item 3 score ≥ 7) [91]. This finding is consistent with previous studies showing benefit in patients with high baseline fatigue, but additional RCTs are needed to provide clarity. NCCN guidelines do not recommend the use of modafinil to treat CRF [37].

Other pharmacologic interventions. Corticosteroids are often used for symptom control in cancer patients. These drugs have anti-inflammatory effects through their modulation of pro-inflammatory cytokines [92]. In a RCT evaluating the efficacy of corticosteroids, patients receiving dexamethasone (4 mg twice daily) experienced significant improvement in their FACT-F scores compared with patients receiving placebo [93]. A similar benefit in fatigue was demonstrated in another study of methylprednisolone (32 mg daily) versus placebo [94]. Despite the benefits of steroids, their adverse effects, such as mood swings, gastritis, hyperglycemia, and immune suppression, limit their long-term use. Therefore, the use of steroids should be restricted to terminally ill fatigued patients with other symptoms such as anorexia, brain metastasis, or pain related to bone metastasis [37].

Testosterone replacement has been shown to diminish fatigue in non-cancer patients. Many men with advanced cancer have hypogonadism leading to low serum testosterone, which may cause fatigue. In a small trial in which cancer patients with hypogonadism received intramuscular testosterone every 14 days or placebo, the group receiving testosterone showed improvement in FACT-F scores, but there was no significant difference in FACT-F scores between the 2 groups [95].

Antidepressants have failed to demonstrate benefit in CRF without depression [8]. However, if a patient has both fatigue and depression, antidepressants may help [96]. A selective serotonin receptor inhibitor is recommended as a first-line antidepressant [97]. Patients with cancer are often receiving multiple medications, and medication interactions should be considered to prevent adverse events such as serotonin syndrome.

Complementary and Alternative Supplements

Studies using vitamin supplementation have been inconclusive in patients with CRF [74]. The use of other dietary supplements has yielded mixed results, and coenzyme Q has shown no benefit for patients with CRF [98].

The benefit of ginseng was studied in a RCT involving 364 patients with CRF. There was an improvement in Multidimensional Fatigue Symptom Inventory-short form (MFSI-SF) scores at 8 weeks in patients receiving 2000 mg of Wisconsin ginseng compared with patients receiving placebo [99]. Patients on active treatment had greater improvement as compared to the post-treatment group in this trial. In another study of high-dose panax ginseng (ginseng root) at 800 mg daily for 29 days, patients had improvement of CRF as well as overall quality of life, appetite, and sleep at night. It was also well tolerated with few adverse effects [100]. Interaction with warfarin, calcium channel blockers, antiplatelet agents, thrombolytic agents, imatinib, and other agents may occur; therefore, ginseng must be used with careful monitoring in selected patients. There is not enough evidence at this time to support the routine use of ginseng in CRF.