In the small case study, the researchers report on four patients who appeared to have an improvement in the clinical state of their disease after starting over-the-counter products containing epigallocatechin gallate (EGCG), an extract of green tea. Three of the four patients met the standard criteria used to define a response treatment for clinical trials. These same investigators had previously shown that EGCG kills leukemia cells from patients with CLL in the test tube by interrupting the communication signals they need to survive.
"The experience of these individuals provides some suggestion that our previously published laboratory findings may actually translate into clinical effects for patients with this disease," says Tait Shanafelt, M.D., Mayo Clinic haematologist. Despite these encouraging preliminary findings, he urges caution. "We do not know how many patients were taking similar products and failed to have any benefit. We also do not yet know the optimal dose that should be used, the frequency with which patients should take the medication, and what side effects will be observed with long-term administration."
Dr. Shanafelt and his colleagues say more studies are needed to determine these things before they would recommend widespread use by patients. Dr. Shanafelt is also the lead investigator in an ongoing clinical trial sponsored by the National Cancer Institute studying pharmacologic doses of EGCG in pill form for patients with CLL.
"Green tea has long been thought to have cancer-prevention capabilities," says Dr. Shanafelt. "It is exciting that research is now demonstrating this agent may provide new hope for CLL patients."
MEDICA.de; Source: Mayo Clinic