***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 Purpose : Green tea has been shown to exhibit cancer-preventive activities in pre clinical studies . Its consumption has been associated with decreased risk of certain types of cancers in humans . The oral bioavailability of the major green tea constituents , green tea catechins , is low , result ing in systemic catechin levels in humans many fold less than the effective concentrations determined in in vitro systems . We conducted this clinical study to test the hypothesis that the oral bioavailability of green tea catechins can be enhanced when consumed in the absence of food . Experimental Design s : Thirty healthy volunteers were r and omly assigned to one of the following doses of Polyphenon E ( a decaffeinated and defined green tea catechin mixture ) : 400 , 800 , or 1,200 mg , based on the epigallocatechin gallate content ( 10 subjects per dose group ) . After an overnight fast , study participants took a single dose of Polyphenon E with or without a light breakfast , which consisted of one or two 4-oz muffins and a glass of water . Following a 1-week wash-out period , subjects were crossed over to take the same dose of Polyphenon E under the opposite fasting/fed condition . Tea catechin concentrations in plasma and urine sample s collected after dosing were determined by high-pressure liquid chromatography analysis . Results : Consistent with previous reports , epigallocatechin gallate and epicatechin gallate were present in plasma mostly as the free form , whereas epicatechin and epigallocatechin were mostly present as the glucuronide and sulfate conjugates . There was > 3.5-fold increase in the average maximum plasma concentration of free epigallocatechin gallate when Polyphenon E was taken in the fasting condition than when taken with food . The dosing condition led to a similar change in plasma-free epigallocatechin and epicatechin gallate levels . Taking Polyphenon E in the fasting state did not have a significant effect on the plasma levels of total ( free and conjugated ) epigallocatechin , but result ed in lower plasma levels of total epicatechin . Urinary epigallocatechin gallate and epicatechin gallate levels were very low or undetectable following Polyphenon E administration with either dosing condition . Taking Polyphenon E under the fasting state result ed in a significant decrease in the urinary recovery of total epigallocatechin and epicatechin .  Polyphenon E administered as a single dose over the dose range studied was generally well-tolerated by the study participants . Mild and transient nausea was noted in some of the study participants and was seen most often at the highest study agent dose ( 1,200 mg epigallocatechin gallate ) and in the fasting condition . Conclusions : We conclude that greater oral bioavailability of free catechins can be achieved by taking the Polyphenon E capsules on an empty stomach after an overnight fast . Polyphenon E up to a dose that contains 800 mg epigallocatechin gallate is well-tolerated when taken under the fasting condition . This dosing condition is also expected to optimize the biological effects of tea catechins 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 Abstract : There is some evidence from case-control studies that coffee consumption might be positively associated with ovarian cancer risk , whereas the epidemiologic evidence regarding tea consumption and ovarian cancer is inconsistent . To date , there have been few prospect i ve studies of these associations . Therefore , we examined ovarian cancer risk in association with both coffee and tea intake in a prospect i ve cohort study of 49,613 Canadian women enrolled in the National Breast Screening Study ( NBSS ) who completed a self-administered food frequency question naire between 1980 and 1985 . Linkages to national mortality and cancer data bases yielded data on deaths and cancer incidence , with follow-up ending between 1998 and 2000 . Data from the food frequency question naire were used to estimate daily intake of coffee and tea .  Cox proportional hazards models were used to estimate hazard ratios ( HR ) and 95 % confidence intervals ( CI ) for the association between categories of  coffee and tea intake and ovarian cancer risk . During a mean 16.4 years of follow-up , we observed 264 incident ovarian cancer cases .  Tea intake was not associated with ovarian cancer risk in our study population . In contrast , a borderline positive association was observed among women who drank > 4 cups coffee/day compared to women who did not drink coffee ( HR = 1.62 , 95 % CI = 0.95–2.75 , P trend = 0.06 ) . Given the pervasive use of these beverages , the associations between  coffee and tea consumption and ovarian cancer risk warrant investigation in further prospect i ve studies BACKGROUND Substantial evidence from laboratory studies indicates that green and black tea preparations may protect against various cancers . Few epidemiologic studies , however , have examined the relationship specifically between tea consumption and risk of ovarian cancer . METHODS We prospect ively examined the association between tea consumption and risk of ovarian cancer in 61 057 women aged 40 to 76 years who were participants in the population -based Swedish Mammography Cohort . Participants completed a vali date d 67-item food frequency question naire at enrollment between 1987 and 1990 and were followed for cancer incidence through December 2004 . RESULTS During an average follow-up of 15.1 years , 301 incident cases of invasive epithelial ovarian cancer were ascertained . Tea consumption was inversely associated with the risk of ovarian cancer after controlling for potential confounders ( P for trend , .03 ) . Compared with women who never or seldom ( less than monthly ) consumed tea , the multivariate hazard ratios for those who consumed less than 1 cup per day , 1 cup per day , and 2 or more cups per day were 0.82 ( 95 % confidence interval [ CI ] , 0.62 - 1.08 ) , 0.76 ( 95 % CI , 0.56 - 1.04 ) , and 0.54 ( 95 % CI , 0.31 - 0.91 ) , respectively . Each additional cup of tea per day was associated with an 18 % lower risk of ovarian cancer ( multivariate hazard ratio , 0.82 ; 95 % CI , 0.68 - 0.99 ) . CONCLUSION These results suggest that tea consumption is associated with a reduced risk of epithelial ovarian cancer in a dose-response manner Tea has consistently been shown to inhibit the occurrence of tumors in experimental animals . The evidence for such a beneficial effect in humans , however , is limited . The authors examined the association between non-herbal tea consumption and cancer incidence in a prospect i ve cohort study of 35,369 postmenopausal Iowa women . In this cohort , information on the frequency of tea drinking and other dietary and lifestyle factors was collected by mailed survey in 1986 . After 8 years of follow-up , 2,936 incident non-skin cancer cases were ascertained in this cohort through the State Health Registry of Iowa . Proportional hazards regressions were used to derive adjusted relative risks and 95 % confidence intervals for the association between tea consumption and cancer incidence . After controlling for confounding factors , the authors found that regular tea consumption was related to a slight , but not statistically significant , reduced incidence of all cancers combined . Inverse associations with increasing frequency of tea drinking were seen for cancers of the digestive tract ( p for trend , 0.04 ) and the urinary tract ( p for trend , 0.02 ) . For women who reported drinking > or = 2 cups ( 474 ml ) of tea per day , compared with those who never or occasionally drank tea , the relative risk for digestive tract cancers was 0.68 ( 95 % confidence interval ( CI ) 0.47 - 0.98 ) and for urinary tract cancers , 0.40 ( 95 % CI 0.16 - 0.98 ) . Similar inverse associations were seen for specific digestive and urinary tract cancers , although site-specific analyses were not statistically significant . No appreciable association of  tea drinking was found with melanoma , non-Hodgkin 's lymphoma , or cancers of the pancreas , lung , breast , uterine corpus , or ovary . This study suggests that tea , one of the most popular beverages consumed worldwide , may protect against some cancers in postmenopausal women Flavonoids are antioxidant compounds found in plants , including fruits , vegetables and tea . No prior prospect i ve studies have examined the association between intake of flavonoids in the flavonol and flavone subclasses and ovarian cancer risk . We analyzed the association between intake of 5 common dietary flavonoids and incidence of epithelial ovarian cancer among 66,940 women in the Nurses ' Health Study . We calculated each participant 's intake of myricetin , kaempferol , quercetin , luteolin and apigenin from dietary data collected at multiple time points , and used Cox proportional hazards regression to model the incidence rate ratio ( RR ) of ovarian cancer for each quintile of intake . Our analysis included 347 cases diagnosed between 1984 and 2002 , and 950,347 person-years of follow-up . There was no clear association between total intake of the 5 flavonoids examined and incidence of ovarian cancer ( RR = 0.75 for the highest versus lowest quintile , 95 % confidence interval [ CI ] = 0.51 - 1.09 ) . However , there was a significant 40 % decrease in ovarian cancer incidence for the highest versus lowest quintile of kaempferol intake ( RR = 0.60 , 95 % CI = 0.42 - 0.87 ; p-trend = 0.002 ) , and a significant 34 % decrease in incidence for the highest versus lowest quintile of luteolin intake ( 
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RESULTS In epithelial ovarian cancer cell lines , green tea and green tea components have been shown to downregulate the expression of proteins involved in inflammation , cell signalization , cell motility and angiogenesis .
Green tea and green tea components would induce apoptosis and could potentiate the effects of cisplatin , a chemotherapeutic agent .
Available literature suggests potential molecular targets for green tea in ovarian cancer treatment and also provides data supporting the clinical evaluation of the role of green tea or green tea components in ovarian cancer prevention and treatment