Green tea and lung cancer: a systematic review

Green tea is a beverage widely used by lung cancer patients and the public for its purported anticancer properties. The authors conducted a systematic review of green tea for the treatment and prevention of lung cancer.

Six electronic databases were searched from inception until November 2011 for human interventional and preclinical evidence pertaining to the safety and efficacy of green tea for lung cancer.

A total of 84 articles met inclusion criteria: two Phase I trials, three reports of one surrogate study, and 79 preclinical studies. There is a lack of controlled trials investigating green tea for lung cancer. Two Phase I studies showed no objective tumor responses at the maximum tolerated dose, ranging from 3 to 4.2 g/m(2) green tea extract (GTE) per day. Four cups of green tea daily decreased DNA damage (8OH-dG) in smokers. Human studies indicate that 800mg of green tea catechins daily does not alter activity of the CYP2D6, CYP1A2, CYP3A4 and CYP2C9 enzymes, however in vitro evidence suggests that green tea may bind to and reduce the effectiveness of bortezomib. Green tea applied topically may improve the healing time of radiation burns.

Although some evidence suggests that chemopreventative benefits can be accrued from green tea, there is currently insufficient evidence to support green tea as a treatment or preventative agent for lung cancer. Green tea should not be used by patients on bortezomib therapy. Further research is warranted to explore this natural agent for lung cancer treatment and prevention.