绿茶对抗白血病

Green Tea Compound May Fight Leukemia
7 P$ W+ |* B: P" {9 r, e' K8 L; EEarly Study Shows EGCG Supplements May Delay Need for Chemotherapy in Some Patients
By Charlene Laino
# v! F8 X/ W: x2 V* nWebMD Health NewsReviewed by Laura J. Martin, MDJune 9, 2010 (Chicago) -- Supplements that contain a chemical found in green tea show promise for delaying or preventing the need for chemotherapy in people with early-stage chronic lymphocytic leukemia (CLL).

The chemical is called epigallocatechin gallate (EGCG). In a small preliminary studyof 42 CLL patientswho took pills containing EGCG, about one-third showed a 20% or greater drop in their leukemia cell count that was sustained for at least several months.

5 c  z  `! g' VSince the patients in the study had such early-stage disease that most had no symptoms, the FDA and the researchers agreed that a drop in leukemia cell count would be used as a surrogate marker for disease activity, says study head Tait Shanafelt, MD, a hematologist at the Mayo Clinic in Rochester, Minn.
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In the 29 patients who had enlarged lymph nodes, 20 saw their node size cut in half or more following treatment, he tells WebMD.

Patients took the EGCG pills twice a day for six months. EGCG was generally well tolerated, but three patients had serious side effects: one had abdominal pain, one had severe fatigue, and one had substantially elevated liver enzymes.

. h' s6 z8 N; u" }6 A/ bThe findings were presented at the American Society of Clinical Oncology annual meeting.
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$ [8 M' d' s( R* ~' WLaboratory studies in a variety of tumor types have shown that EGCG cuts off the nutrient-rich blood supply to tumors and directly kills off cancer cells, Shanafelt says. Last year his team published a small study showing EGCG appears to be safe.

If the findings are confirmed and long-term safety established in larger, longer studies, the hope is that EGCG supplements can delay or prevent chemo, he says.
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CLL is a very slow growing leukemia, he says. "So for the 70% to 80% of patients diagnosed at an early stage, we wait for the development of symptoms to start chemotherapy," Shanafelt says.
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6 k: p7 B  a- m( xThe other potential niche is to use ECCG as maintenance therapy to prevent recurrence in patients who are in remission, Shanafelt says.

EGCG supplements can be bought at any health food store, and Shanafelt says he receives about one email a month from CLL patients who claim they help.

Pending further study, Shanafelt doesn't advise taking the supplements, which contain much more EGCG than you can get from green tea.
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But if you are going to swallow them, at least tell your oncologist and get blood tests to check your liver enzymes every six weeks, he says.

" E9 D! v  u. k8 W/ f8 {Ohio State University Comprehensive Cancer Center's John Byrd, MD, who served as discussant for the presentation, says that patients who saw early reports of effectiveness in the literature often ask him if they should be taking EGCG.
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The new findings suggest EGCG is generally well tolerated and appears to have some benefit for some patients, he says.

! b$ }0 |% d% Y: j: Z: @8 bBut much more work is needed, Byrd says.

1 o- ~! J% H) Q% E' q/ ~This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical