Green tea component may slow chronic lymphocytic leukemia

But researchers at the U.S. Mayo Clinic caution that the finding was preliminary as effect seen only in early stages of disease.

The researchers are now in the second phase of trials with early-stage, asymptomatic patients to explore the potential of epigallocatechin gallate (EGCG) to strike a blow against this type of leukemia.

The latest research builds on earlier Mayo lab work from eight years ago, during which EGCG's potential to curtail the survival of CLL leukemia cells was first noted.

The current trial marks the first time this green tea extract has been studied in actual patients as a treatment option for an illness that is described as a hybrid between leukemia and lymphoma.

A total of 42 CLL patients were involved in the phase 2 trial. All were at such an early point in their illness that they were not taking any other treatment.

Nearly one-third showed a 20 percent or greater drop in their leukemia cell count after being treated with EGCG.

What's more, almost 70 percent of the patients who had enlarged lymph nodes saw their node size cut in half or more following treatment, the researchers found.

"The benefits we have seen in most CLL patients who use the chemical suggest that it has modest clinical activity and may be useful for stabilizing this form of leukemia, potentially slowing it down," lead author Dr. Tait Shanafelt, a Mayo Clinic hematologist, said.

Yet despite the encouraging findings, the study authors cautioned that EGCG would not ultimately replace chemotherapy. And they expressed hesitancy with respect to any current patient use of the compound while research is ongoing.

"Without a phase 3 clinical trial, we cannot make a recommendation that EGCG be used by CLL patients," said co-author Dr. Neil Kay, a hematology researcher. "But those who want to take supplements should consult with their oncologists and need to receive appropriate monitoring using laboratory tests."