Objective: Cat's claw (Uncaria tomentosa) is a native Amazon plant that exhibits anti-inflammatory and antitumor properties. We wanted to assess its activity for symptom management of terminal cancer patients.
Methods: This prospective phase II study assessed the effects of a 100-mg dose of a dry extract of U. tomentosa three times per day in patients with advanced solid tumors who had no further therapeutic options and a life expectancy of at least 2 months. The European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ C30) and Functional Assessment of Chronic Illness Therapy - Fatigue questionnaires were used to assess the participants' quality of life, the Hospital Anxiety and Depression Scale questionnaire was used to assess anxiety and depression, and the Pittsburgh Sleep Quality Index was used to assess sleep quality. In addition, several biochemical and inflammatory parameters were analyzed.
Results: Fifty-one volunteers were recruited. Their median age was 64 (range, 33-85) years, and 47% of patients were female. More than 65% of patients had scores on the Karnofsky Performance Scale of 80% or less. Treatment improved the patients' overall quality of life (p=0.0411) and social functioning (p=0.0341), as assessed by the EORTC QLQ C-30, and reduced fatigue (p=0.0496) according to the Chalder Fatigue Questionnaire. None of the biochemical or inflammatory parameters assessed (interleukin-1 and -6, C-reactive protein, tumor necrosis factor-α, erythrocyte sedimentation rate, and α-1-acid glycoprotein) changed significantly. No tumor response was detected according to the Response Evaluation Criteria In Solid Tumors; however, the disease stabilized for more than 8 months in four participants. The medication was well tolerated by most patients.
Conclusion: Use of cat's claw might be beneficial in patients with advanced cancer by improving their quality of life and reducing fatigue. The mechanism of action does not seem to be related to the anti-inflammatory properties of this plant.