Regression of follicular lymphoma with Devil's Claw: coincidence or causation?

Cancer patients frequently use alternative therapies. Two follicular lymphoma patients who had objective tumour regression after taking Devil's Claw without cytotoxic therapy are reported here.

Patient 1 presented with coexistent immunoglobulin G plasma cell dyscrasia and stage iiia lymphoma (nodes 5 cm in diameter). Computed tomography scan 10 months later showed partial regression. On enquiry, it was learned that the patient was taking Devil's Claw and Essiac (Essiac Products Services, Pompano Beach, FL, U.S.A.). This patient later developed overt myeloma, at which time he stopped the herbal supplements and underwent high-dose chemotherapy and stem cell transplantation, since which no lymphoma progression has occurred. Patient 2 presented with stage IIIA lymphoma (nodes 2.5 cm in diameter). He learned of patient 1 through our lymphoma patient support group and started Devil's Claw. Computed tomography scan 11 months later showed decreased adenopathy and splenomegaly, which has been sustained for 4 years.

Devil's Claw tuberous root has anti-inflammatory properties, probably through suppression of cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase expression. There are no prior reports of anticancer activity. Inhibition of COX-2 has a role in colon cancer prevention, has been implicated in lymphomagenesis, and is associated both with lymphoma stage and with response to treatment. However, spontaneous regression in lymphoma has been reported in 16% of patients in one series, of whom none were on herbal medications or COX-2 inhibitors. The key issue in both these patients is whether disease regression was "spontaneous" or causally related to therapy with Devil's Claw. The timing of the response suggests a positive effect. Further investigation is warranted, preferably with a COX-2 inhibitor of known purity.