Green Tea Extract Fights Oral Cancer

DALLASGreen tea extract has shown promise as cancer prevention agent for oral cancer in patients with a pre-malignant condition known as oral leukoplakia, according to a new study from The University of Texas M. D. Anderson Cancer Center.

Reseachers examined green tea as a chemopreventative agent in this high-risk patient population and found that more than half of the oral leukoplakia patients who took the extract had a clinical response. The results were published online in Cancer Prevention Research.

In the Phase II dose-finding study, 41 M. D. Anderson oral leukoplakia patients were randomized between August 2002 and March 2008 to receive either green tea extract or placebo. Participants took the extract, an oral agent, for three months at one of three doses500 per meter squared of body mass (mg/m2); 750 mg/m2 or 1,000 mg/m2 - three times daily. Participants also underwent a baseline and 12-week biopsy to best assess biomarkers.

Of those taking green tea at the two highest doses, 58.8 percent had a clinical response, compared with 36.4 percent in the lowest extract dose and 18.2 percent in the placebo arm. At an extended follow-up with a mean of 27.5 months, 15 participants had developed oral cancer, with a median time to disease development of 46.4 months.

"While still very early, and not definitive proof that green tea is an effective preventive agent, these results certainly encourage more study for patients at highest risk for oral cancer," said Vassiliki Papadimitrakopoulou, MD., professor in M. D. Anderson's Department of Thoracic/Head and Neck Medical Oncology, and the study's senior author. "The extract's lack of toxicity is attractive in prevention trials, it's very important to remember that these are otherwise healthy individuals and we need to ensure that agents studied produce no harm."