***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Purpose Epidemiologic studies suggest that consumption of green tea may have a protective effect against the development of several cancers . Pre clinical studies of green tea and its polyphenolic components have demonstrated antimutagenic and anticarcinogenic activity , and inhibition of growth of tumor cell lines and animal tumor models , including lung cancer . Green tea may also have chemopreventive properties , and enhancement of cytotoxicity of chemotherapeutic agents has been demonstrated . This trial was design ed to determine the maximum tolerated dose ( MTD ) of green tea extract ( GTE ) in patients with advanced lung cancer . Methods A total of 17 patients with advanced lung cancer were registered to receive once-daily oral dosing of GTE at a starting dose of 0.5 g/m2 per day , with an accelerated dose-escalation scheme . Results On this schedule , the MTD of GTE was 3 g/m2 per day , and at this dose ,  GTE  was well tolerated with no grade 3 or 4 toxicity seen . Dose-limiting toxicities were diarrhea , nausea and hypertension . No objective responses were seen in this trial . Seven patients had stable disease ranging from 4 to 16 weeks ; no patient remained on therapy longer than 16 weeks due to the development of progressive disease . Conclusions This study suggests that while relatively nontoxic at a dose of 3 g/m2 per day , GTE likely has limited activity as a cytotoxic agent , and further study of GTE as a single-agent in established malignancies may not be warranted . Further studies should focus on the potential chemopreventive and chemotherapy-enhancing properties of GTE CONTEXT Green tea polyphenols have been extensively studied as cardiovascular disease and cancer chemopreventive agents in vitro and in animal studies . However , the effects of green tea consumption in humans remain unclear . OBJECTIVE To investigate the associations between green tea consumption and all-cause and cause-specific mortality . DESIGN , SETTING , AND PARTICIPANTS The Ohsaki National Health Insurance Cohort Study , a population -based , prospect i ve cohort study initiated in 1994 among 40,530 Japanese adults aged 40 to 79 years without history of stroke , coronary heart disease , or cancer at baseline . Participants were followed up for up to 11 years ( 1995 - 2005 ) for all-cause mortality and for up to 7 years ( 1995 - 2001 ) for cause-specific mortality . MAIN OUTCOME MEASURES Mortality due to cardiovascular disease , cancer , and all causes . RESULTS Over 11 years of follow-up ( follow-up rate , 86.1 % ) , 4209 participants died , and over 7 years of follow-up ( follow-up rate , 89.6 % ) , 892 participants died of cardiovascular disease and 1134 participants died of cancer .  Green tea consumption was inversely associated with mortality due to all causes and due to cardiovascular disease . The inverse association with all-cause mortality was stronger in women ( P = .03 for interaction with sex ) . In men , the multivariate hazard ratios of mortality due to all causes associated with different green tea consumption frequencies were 1.00 ( reference ) for less than 1 cup/d , 0.93 ( 95 % confidence interval [ CI ] , 0.83 - 1.05 ) for 1 to 2 cups/d , 0.95 ( 95 % CI , 0.85 - 1.06 ) for 3 to 4 cups/d , and 0.88 ( 95 % CI , 0.79 - 0.98 ) for 5 or more cups/d , respectively ( P = .03 for trend ) . The corresponding data for women were 1.00 , 0.98 ( 95 % CI , 0.84 - 1.15 ) , 0.82 ( 95 % CI , 0.70 - 0.95 ) , and 0.77 ( 95 % CI , 0.67 - 0.89 ) , respectively ( P<.001 for trend ) . The inverse association with cardiovascular disease mortality was stronger than that with all-cause mortality . This inverse association was also stronger in women ( P = .08 for interaction with sex ) . In women , the multivariate hazard ratios of cardiovascular disease mortality across increasing green tea consumption categories were 1.00 , 0.84 ( 95 % CI , 0.63 - 1.12 ) , 0.69 ( 95 % CI , 0.52 - 0.93 ) , and 0.69 ( 95 % CI , 0.53 - 0.90 ) , respectively ( P = .004 for trend ) . Among the types of cardiovascular disease mortality , the strongest inverse association was observed for stroke mortality . In contrast , the hazard ratios of cancer mortality were not significantly different from 1.00 in all green tea categories compared with the lowest-consumption category . CONCLUSION Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer Our study investigates whether tea consumption can enhance the survival of patients with epithelial ovarian cancer , a prospect i ve cohort study was conducted in Hangzhou , China . The cohort comprised 254 patients recruited during 1999 - 2000 with histopathologically confirmed epithelial ovarian cancer and was followed up for a minimum of 3 years . Two hundred forty four ( 96.1 % ) of the cohort or their close relatives were traced . The variables examined included their survival time and the  frequency and quantity of tea consumed post-diagnosis .  The actual number of deaths was obtained and Cox proportional hazards models were used to obtain hazard ratios and associated 95 % confidence intervals ( CI ) , adjusting for age at diagnosis , locality , BMI , parity , FIGO stage , histologic grade of differentiation , cytology of ascites , residual tumour and chemotherapeutic status . The survival experience was different between tea drinkers and non-drinkers ( p < 0.001 ) . There were 81 ( 77.9 % ) of 104 tea-drinkers who survived to the time of interview , compared to only 67 women ( 47.9 % ) still alive among the 140 non-drinkers . Compared to non-drinkers , the adjusted hazard ratios were 0.55 ( 95 % CI = 0.34 - 0.90 ) for tea-drinkers , 0.43 ( 95 % CI = 0.20 - 0.92 ) for consuming at least 1 cup of green tea/day , 0.44 ( 95 % CI = 0.22 - 0.90 ) for brewing 1 batch or more of green tea/day , 0.40 ( 95 % CI = 0.18 - 0.90 ) for consuming more than 500 g of dried tea leaves/year , and 0.38 ( 95 % CI = 0.15 - 0.97 ) for consuming at least 2 g of dried tea leaves/batch . The corresponding dose-response relationships were significant ( p < 0.05 ) . We conclude that increasing the consumption of green tea post-diagnosis may enhance epithelial ovarian cancer survival The incidence of prostate cancer is much lower in Asian than Western population s. Given that environmental factors such as dietary habits may play a major role in the causation of prostate cancer and the high consumption of green tea in Asian population s , this low incidence may be partly due to the effects of green tea . The JPHC Study ( Japan Public Health Center-based Prospect i ve Study ) was established in 1990 for cohort I and in 1993 for cohort II . The subjects were 49,920 men aged 40 - 69 years who completed a question naire that included their green tea consumption habit at baseline and were followed until the end of 2004 . During this time , 404 men were newly diagnosed with prostate cancer , of whom 114 had advanced cases , 271 were localized , and 19 were of an undetermined stage .  Green tea was not associated with localized prostate cancer . However , consumption was associated with a dose-dependent decrease in the risk of advanced prostate cancer . The multivariate relative risk was 0.52 ( 95 % confidence interval : 0.28 , 0.96 ) for men drinking 5 or more cups/day compared with less than 1 cup/day ( p(trend ) = 0.01 ) . Green tea may be associated with a decreased risk of advanced prostate cancer In a prospect i ve study of 19 561 Japanese men , green-tea intake was not associated with a lower risk of prostate cancer ( 110 cases ) , the multivariate hazard ratio for men drinking ⩾5 cups compared with < 1 cup per day being 0.85 ( 95 % confidence interval 0.50–1.43 , trend P=0.81 ) PURPOSE This trial was design ed to determine the maximum-tolerated dose , toxicity , and pharmacology of oral green tea extract ( GTE ) once daily or three times daily . PATIENTS AND METHODS Cohorts of three or more adult cancer patients were administered oral GTE with water after meals one or three times daily for 4 weeks , to a maximum of 6 months , depending on disease response and patient tolerance . Pharmacokinetic analyses were encouraged but optional . RESULTS Dose levels of 0.5 to 5.05 g/m(2 ) qd and 1.0 to 2.2 g/m(2 ) tid were explored . A total of 49 patients were studied . PATIENT CHARACTERISTICS median age , 57 years ( range , 27 to 77 years ) ; 23 patients were women ( 47 % ) ; 98 % had a Zubrod PS of 1 % ; 98 % had PS of 1 ; and 21 had non-small-cell lung , 19 had head & neck cancer , three had mesothelioma , and six had other .  Mild to moderate toxicities were seen at most dose levels and promptly reversed on discontinuation of GTE .  Dose-limiting toxicities were caffeine related and included neurologic and gastrointestinal effects . The maximum-tolerated dose was 4.2 g/m(2 ) once daily or 1.0 g/m(2 ) three times daily . No major responses occurred ; 10 patients with stable disease completed 6 months of GTE . Pharmacokinetic analyses found accumulation of caffeine levels that were dose dependent , whereas epigallocatechin gallate levels did not accumulate nor appear dose related . CONCLUSION A dose of 1.0 g/m(2 ) tid ( equivalent to 7 to 8 Japanese cups [ 120 mL ] of green tea three times daily ) is recommended for future studies . The side effects of this preparation of GTE were caffeine related . Oral GTE at the doses studied can be taken safely for at least 6 months PURPOSE To evaluate the efficacy and toxicity of green tea , prescribed as an alternative complementary ( CAM ) formulation on hormone refractory prostate cancer ( HRPC ) . METHODS Patients with HRCP were prescribed green tea extract capsules at a dose level of 250 mg twice daily . Efficacy and toxicity were evaluated during monthly visits . The primary endpoint was prostate-specific antigen ( PSA ) or measurable disease progression after a minimum of 2 months of therapy . RESULTS Nineteen patients were enrolled into the study . The treatment was generally well tolerated . Twelve patients reported at least one side effect ; only two of these were of moderate or severe grade . Primary toxicity was related to gastrointestinal irritation or caffeine intake . Four patients did not complete the minimum 2 months of therapy because of : intolerance ( two patients ) , physician stoppage ( one patient ) , death from cerebrovascular accident ( one patient ) . Fifteen patients completed at least 2 months of therapy . Nine of these patients had progressive disease within 2 months of starting therapy . Six patients developed progressive disease after additional 1 to 4 months of therapy . CONCLUSION Green tea , as CAM therapy , was found to have minimal clinical activity against hormone refractory prostate cancer BACKGROUND Although laboratory experiments and case-control studies have suggested that the consumption of green tea provides protection against gastric cancer , few prospect i ve studies have been performed . METHODS In January 1984 , a total of 26,311 residents in three municipalities of Miyagi Prefecture , in northern Japan ( 11,902 men and 14,409 women 40 years of age or older ) , completed a self-administered question naire that included questions about the frequency of consumption of green tea . During 199,748 person-years of follow-up , through December 1992 , we identified 419 cases of gastric cancer ( in 296 men and 123 women ) . We used Cox regression to estimate the relative risk of gastric cancer according to the consumption of green tea . RESULTS Green-tea consumption was not associated with the risk of gastric cancer . After adjustment for sex , age , presence or absence of a history of peptic ulcer smoking status , alcohol consumption , other dietary elements , and type of health insurance , the relative risks associated with drinking one or two , three or four , and five or more cups of green tea per day , as compared with less than one cup per day , were 1.1 ( 95 percent confidence interval , 0.8 to 1.6 ) , 1.0 ( 95 percent confidence interval , 0.7 
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Although the evidence from this review suggested associations between green tea consumption and a decreased risk for some cancers , the findings were inconclusive .
In selected cases , green tea was effective in slowing the progression of the earlier stages of cancer .
However , contrary evidence is reported and the dose and duration of use is variable .