Green tea compound may fight leukaemia

9th June 2010 - 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 leukaemia (CLL).

The chemical is called epigallocatechin gallate (EGCG). In a small preliminary study of 42 CLL patients who took tablets containing EGCG, about a third showed a 20% or greater drop in their leukaemia cell count that was sustained for at least several months.

Since the patients in the study had such early-stage disease that most had no symptoms, the US drug regulator (FDA) and the researchers agreed that a drop in leukaemia cell count would be used as a surrogate marker for disease activity, says study head Dr Tait Shanafelt, a haematologist at the US Mayo Clinic.

In the 29 patients who had enlarged lymph nodes, 20 saw their node size cut in half or more following treatment, he tells us.

Patients took the EGCG tablets 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.

The findings were presented at the American Society of Clinical Oncology annual meeting.

Laboratory studies in a variety of tumour types have shown that EGCG cuts off the nutrient-rich blood supply to tumours 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.

CLL is a very slow growing leukaemia, 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.

The 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 shop, 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.

However, if you are going to swallow them, at least tell your oncologist and ask for blood tests to check your liver enzymes every six weeks, he says.
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 journal.