Coffee and alcohol intake and risk of ovarian cancer: an Italian case-control study

Association between coffee and tea consumption and ovarian cancer incidence: A prospective analysis in the PLCO dataset

Epidemiological evidence regarding the relationship between coffee and tea consumption and the risk of ovarian cancer (OC) is inconsistent. Therefore, we aimed to quantitatively investigate this topic in a large prospective cohort study. This cohort study included 24,715 individuals recruited from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trials between 1993 and 2001. The data used for our analysis included the latest follow-up information collected up to 2015. Coffee intake of ≥4 cups/day (hazard ratio [HR], 0.586; 95% confidence interval [CI]: 0.356-0.966) or caffeine intake of 458.787 mg/day (HR, 0.607; 95% CI: 0.411-0.895) were associated with the lowest HR of incident OC in the fully adjusted model. Participants who consumed varying amounts of tea did not exhibit a statistically significant reduction in the risk of OC. Our findings suggest that a higher consumption of coffee or caffeine is associated with a reduced risk of OC. However, no statistically significant association was observed between tea consumption and the risk of OC.

Association between wine consumption and cancer: a systematic review and meta-analysis

Background

Alcohol consumption is related to the risk of developing different types of cancer. However, unlike other alcoholic beverages, moderate wine drinking has demonstrated a protective effect on the risk of developing several types of cancer.

Objective

To analyze the association between wine consumption and the risk of developing cancer.

Methods

We searched the MEDLINE (through PubMed), Scopus, Cochrane, and Web of Science databases to conduct this systematic review and meta-analysis. Pooled relative risks (RRs) were calculated using the DerSimonian and Laird methods. I2 was used to evaluate inconsistency, the τ2 test was used to assess heterogeneity, and The Newcastle-Ottawa Quality Assessment Scale were applied to evaluate the risk of bias. This study was previously registered in PROSPERO, with the registration number CRD42022315864.

Results

Seventy-three studies were included in the systematic review, and 26 were included in the meta-analysis. The pooled RR for the effect of wine consumption on the risk of gynecological cancers was 1.03 (95% CI: 0.99, 1.08), that for colorectal cancer was 0.92 (95% CI: 0.82, 1.03), and that for renal cancer was 0.92 (95% CI: 0.81, 1.04). In general, the heterogeneity was substantial.

Conclusion

The study findings reveal no association between wine consumption and the risk of developing any type of cancer. Moreover, wine drinking demonstrated a protective trend regarding the risk of developing pancreatic, skin, lung, and brain cancer as well as cancer in general.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022315864, identifier CRD42022315864 (PROSPERO).

Alcohol intake and the risk of epithelial ovarian cancer

PURPOSE

To investigate the association between alcohol intake over the lifetime and the risk of overall, borderline, and invasive ovarian cancer.

METHODS

In a population-based case-control study of 495 cases and 902 controls, conducted in Montreal, Canada, average alcohol intake over the lifetime and during specific age periods were computed from a detailed assessment of the intake of beer, red wine, white wine and spirits. Multivariable logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the association between alcohol intake and ovarian cancer risk.

RESULTS

For each one drink/week increment in average alcohol intake over the lifetime, the adjusted OR (95% CI) was 1.06 (1.01-1.10) for ovarian cancer overall, 1.13 (1.06-1.20) for borderline ovarian cancers and 1.02 (0.97-1.08) for invasive ovarian cancers. This pattern of association was similarly observed for alcohol intake in early (15- < 25 years), mid (25- < 40 years) and late adulthood (≥ 40 years), as well as for the intake of specific alcohol beverages over the lifetime.

CONCLUSIONS

Our results support the hypothesis that a higher alcohol intake modestly increases the risk of overall ovarian cancer, and more specifically, borderline tumours.

Potential role of tea extract in oocyte development

Tea is the second most popular beverage in the world and beneficial to health. It has been demonstrated that tea polyphenols can reduce the risk of diseases, such as cancers, diabetes, obesity, Alzheimer's disease, etc. But the knowledge of tea extract on the female germline is limited. Folliculogenesis is a complicated process and prone to be affected by ROS. Tea polyphenols can reduce the accumulation of ROS in folliculogenesis and affect oocyte maturation. Tea extract also influences granulosa cell proliferation and expansion during oocyte growth and maturation. However, the studies about the benefits of tea extract on female germline are few, and the underlying mechanisms are obscure. In the present study, we will mainly discuss the effects of tea extract on ovarian function, oocyte maturation, and the underlying possible mechanisms, and according to the discussion, we suggest that tea extract may have benefits for oocytes at an appropriate dose.

Empirically derived dietary patterns and ovarian cancer risk: a meta-analysis

Dietary patterns, which reflect overall diet and possible nutrient and food interactions, have been reported to be related to ovarian cancer (OC) risk. However, studies on the relationship between dietary patterns and OC risk have been inconsistent. Thus, we carried out a systematic meta-analysis to assess the relationship between dietary patterns and the risk of OC. Relevant studies are identified by searching the Medline and Embase electronic databases up to December 2016. The Cochrane Q statistic and the I statistical were used to evaluate heterogeneity. A total of 22 studies fulfilled the inclusion criteria and were included in this meta-analysis. There was evidence of a decreased risk for OC in the highest versus the lowest categories of healthy dietary pattern [odds ratio (OR)=0.86; 95% confidence interval (CI): 0.74-0.99; P=0.04]. An increased risk of OC was shown for the highest versus the lowest category of a western-style dietary pattern (OR=1.19; 95% CI: 1.01-1.41; P=0.04). No significant association with OC risk was observed in the highest versus the lowest category of a heavy drinking pattern (OR=0.89; 95% CI: 0.67-1.19; P=0.42). The results of this meta-analysis suggest that a healthy dietary pattern is associated with reduced risk for OC and a western-style dietary pattern is associated with an increased risk of OC. Further studies are needed to confirm our results.

Coffee and caffeine intake and risk of ovarian cancer: a systematic review and meta-analysis

Background

Results from earlier publications on the association of coffee and caffeine and risk of ovarian cancer are inconsistent.

Objective

To evaluate the link between coffee, caffeine, caffeinated coffee, and decaffeinated coffee consumption and risk of ovarian cancer.

Methods

We searched PubMed/Medline, ISI Web of Science, Scopus, and Google Scholar to identify relevant publications up to April 2018. All case–control studies that considered coffee, caffeine, caffeinated coffee, or decaffeinated coffee as the exposure variables and ovarian cancer as the main outcome variable or as one of the outcomes were included in the systematic review. Publications in which odds ratios (ORs) or rate or risk ratios (RRs) and 95% confidence intervals (CIs) were reported, were included in the meta-analysis.

Results

A total of 22 case–control studies were included in the systematic review, and 20 studies in the meta-analysis. Overall, 40 140 participants, including 8568 patients with ovarian cancer, aged ≥ 17 years were included. Combining 21 effect sizes from 18 studies, no significant association was observed between total coffee intake and risk of ovarian cancer (OR=1.09; 95% CI 0.94 to 1.26). There was no significant association between total caffeine intake and ovarian cancer risk (OR=0.89; 95% CI 0.55 to 1.45). In addition, caffeinated coffee intake was not significantly associated with ovarian cancer (OR=1.05; 95% CI 0.87 to 1.28). However, combining effect sizes from five studies, we found an inverse significant association between decaffeinated coffee intake and risk of ovarian cancer (OR=0.72; 95% CI 0.58 to 0.90).

Conclusions

Our findings indicated an inverse association between decaffeinated coffee consumption and risk of ovarian cancer. No significant association was found between coffee, caffeine or caffeinated coffee intake and risk of ovarian cancer.

Associations of coffee, tea and caffeine intake with risk of breast, endometrial and ovarian cancer among Canadian women

BACKGROUND

Although, biologically plausible evidence has implicated coffee, tea and caffeine with carcinogenesis, there is a paucity of data on their associations with risk of cancer among Canadian women. Hence, we assessed their associations with risk of breast, endometrial and ovarian cancers within this population.

METHODS

The study comprised a subcohort of 3185 women from a cohort of 39,532 female participants who completed self-administered lifestyle and dietary questionnaires at enrollment. During a median follow-up of approximately 12.2years, we ascertained 922, 180 and 104 breast, endometrial and ovarian cancer cases, respectively. We used Cox proportional hazards regression models modified for the case-cohort design to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for the associations of coffee, tea and caffeine with risk of selected cancers.

RESULTS

Coffee, tea, and caffeine intake were not associated with overall risk of breast and ovarian cancers. There was, however, a tendency towards an increased risk of breast cancer with increasing levels of total coffee, caffeinated coffee and/or caffeine among premenopausal and normal weight women. Total coffee, caffeinated coffee, and caffeine were inversely associated with risk of endometrial cancer (HR_{per cup increase}: 0.88; 95% CI: 0.79-0.95, HR_{per cup increase:} 0.88; 95% CI: 0.80-0.96 and HR_{per 100mg increase:} 0.93; 95% CI: 0.87-0.99, respectively).

CONCLUSION

Our findings suggest that coffee and/or caffeine may be associated with reduced risk of endometrial cancer but, probably, associated increased with risk of breast cancer among premenopausal or normal weight women. However, further studies are needed to confirm our findings.

Tea consumption and the risk of ovarian cancer: A meta-analysis of epidemiological studies

A large number of epidemiological studies have provided conflicting results about the relationship between tea consumption and ovarian cancer. This study aimed to clarify the association between tea consumption and ovarian cancer. A literature search of the MEDICINE, Scopus, PubMed, and Web of Science databases was performed in April 2016. A total of 18 (11 case-control and 7 cohort) studies, representing data for 701,857 female subjects including 8,683 ovarian cancer cases, were included in the meta-analysis. A random-effects meta-analysis was used to compute the pooled relative risks (RR), meta regression, and publication bias, and heterogeneity analyses were performed for the included trials. We found that tea consumption had a significant protective effect against ovarian cancer (relative risk [RR] = 0.86; 95% confidence interval [CI]: 0.76, 0.96). The relationship was confirmed particularly after adjusting for family history of cancer (RR = 0.85; 95% CI: 0.72, 0.97), menopause status (RR = 0.85; 95% CI: 0.72, 0.98), education (RR = 0.82; 95% CI: 0.68, 0.96), BMI (RR = 0.85; 95% CI: 0.70, 1.00), smoking (RR = 0.83; 95% CI: 0.72, 0.93) and Jadad score of 3 (RR = 0.76; 95% CI: 0.56, 0.95) and 5 (RR = 0.74; 95% CI: 0.59, 0.89). The Begg's and Egger's tests (all P > 0.01) showed no evidence of publication bias. In conclusion, our meta-analysis showed an inverse association between tea consumption and ovarian cancer risk. High quality cohort-clinical trials should be conducted on different tea types and their relationship with ovarian cancer.

Ovarian cancer: epidemiology and risk factors

The present overview of ovarian cancer epidemiology summarizes the main results for a network of case-control studies in Italy and from the Collaborative Group on Epidemiological Studies of Ovarian Cancer. There are consistent inverse relations between parity, oral contraceptive use and the risk of ovarian cancer. For other menstrual and hormonal factors (i.e. early age at menarche and late menopause), there are established associations, but of limited impact on ovarian cancer incidence on a population level. Serous and endometrioid ovarian cancers (but not mucinous or clear cell types) are related to current and recent use of hormone replacement therapy in menopause. There are no strong associations with alcohol and tobacco overall, but a direct link for tobacco with (borderline) mucinous cancers, of limited impact, however, on overall ovarian cancer mortality. There are direct associations of ovarian cancer risk with height and BMI, as well as possible relations with selected dietary factors - in the absence, however, of consistent findings - and a possible inverse association with physical activity. There is a strong association with a family history of ovarian cancer (and a few selected other neoplasms, including colorectum and endometrium). Recognized risk factors explain only a limited proportion of ovarian cancer cases on a population level. A key reason for the recent favourable trends of ovarian cancer incidence and mortality in several high-income countries is the widespread use of oral contraceptive in the generations born after 1930.

Coffee, tea, and caffeine consumption and risk of epithelial ovarian cancer and borderline ovarian tumors: Results from a Danish case-control study

BACKGROUND

Epidemiological studies that have investigated the association between coffee, tea and caffeine consumption and ovarian cancer risk have produced conflicting results. Furthermore, only few studies have examined the role of coffee and tea consumption separately for borderline ovarian tumors. By use of data from a large Danish population-based case-control study, we examined the risk of ovarian tumors associated with coffee, tea, and caffeine consumption with a particular focus on characterizing risks by tumor behavior and histology.

MATERIAL AND METHODS

From 1995 through 1999, we included 267 women with ovarian cancer, 115 women with borderline ovarian tumors and 911 randomly selected control women. All women completed a beverage frequency questionnaire with detailed information on coffee and tea consumption. Analyses were performed using multiple logistic regression models.

RESULTS

Both coffee (OR = 0.90; 95% CI 0.84-0.97 per cup/day) and total caffeine consumption from coffee and tea combined (OR = 0.93; 95% CI 0.88-0.98 per 100 mg/day) decreased the risk of ovarian cancer. These associations were significant only for the serous and "other" subtypes of ovarian cancer. No relation between tea consumption and ovarian cancer risk was observed. The risk estimates for borderline ovarian tumors resembled those observed for ovarian cancer, but did not reach statistical significance.

CONCLUSIONS

Our results indicate that coffee consumption and total caffeine consumption from coffee and tea combined is associated with a modest decreased risk of ovarian cancer. However, more biological studies are needed to identify bioactive chemical compounds in coffee that potentially could affect ovarian cancer development.

Tea consumption and cardiovascular disease risk

BACKGROUND

The present analysis was conducted in response to inconsistent epidemiologic studies on the relation between consumption of tea and cardiovascular diseases.

OBJECTIVE

We undertook a literature review of the consistency and strength of the associations between tea and cardiovascular diseases on the basis of published observational studies and meta-analyses addressing tea or tea flavonoids and cardiovascular disease risk.

DESIGN

We performed a search in 3 databases for meta-analyses and compared them with studies they subsumed. We performed an additional search for subsequent studies to determine whether the conclusions were consistent.

RESULTS

Many epidemiologic studies have been conducted and summarized in 5 meta-analyses on either tea consumption or flavonoid consumption and cardiovascular disease or the subset of stroke. Heterogeneity of effect was seen when the outcome included all cardiovascular diseases. In the case of stroke, a consistent, dose-response association with tea consumption on both incidence and mortality was noted with RRs of 0.80 (95% CI: 0.65, 0.98) for flavonoids and 0.79 (95% CI: 0.73, 0.85) for tea when high and low intakes were compared or the addition of 3 cups/d was estimated.

CONCLUSION

Thus, the strength of this evidence supports the hypothesis that tea consumption might lower the risk of stroke.

Green tea for ovarian cancer prevention and treatment: a systematic review of the in vitro, in vivo and epidemiological studies

OBJECTIVE

This systematic review was conducted to examine the effects of green tea or green tea components on the prevention and progression of epithelial ovarian cancer.

METHODS

Using Medline, EMBASE and SciVerse (last researched: July 2011), we retrieved 22 articles including 5 epidemiological studies.

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. In human observational studies, significant associations between green tea intake and both decreased ovarian cancer occurrence and better prognosis were reported.

CONCLUSIONS

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.

Coffee and tea consumption and the risk of ovarian cancer: a prospective cohort study and updated meta-analysis

BACKGROUND

In 2007 the World Cancer Research Fund Report concluded that there was limited and inconsistent evidence for an effect of coffee and tea consumption on the risk of epithelial ovarian cancer (EOC).

OBJECTIVE

In the European Prospective Investigation into Cancer and Nutrition (EPIC), we aimed to investigate whether coffee intakes, tea intakes, or both are associated with the risk of EOC.

DESIGN

All women participating in the EPIC (n = 330,849) were included in this study. Data on coffee and tea consumption were collected through validated food-frequency questionnaires at baseline. HRs and 95% CIs were estimated by using Cox proportional hazards models. Furthermore, we performed an updated meta-analysis of all previous prospective studies until April 2011 by comparing the highest and lowest coffee- and tea-consumption categories as well as by using dose-response random-effects meta-regression analyses.

RESULTS

During a median follow-up of 11.7 y, 1244 women developed EOC. No association was observed between the risk of EOC and coffee consumption [HR: 1.05 (95% CI: 0.75, 1.46) for the top quintile compared with no intake] or tea consumption [HR: 1.07 (95% CI: 0.78, 1.45) for the top quintile compared with no intake]. This lack of association between coffee and tea intake and EOC risk was confirmed by the results of our meta-analysis.

CONCLUSION

Epidemiologic studies do not provide sufficient evidence to support an association between coffee and tea consumption and risk of ovarian cancer.

Alcohol drinking and epithelial ovarian cancer risk. a systematic review and meta-analysis

OBJECTIVE

In order to provide an updated quantification of the association between alcohol drinking and epithelial ovarian cancer risk, we conducted a meta-analysis of published observational studies.

METHODS

Using PubMed, we performed a literature search of all case-control and cohort studies published as original articles in English up to September 2011. We included 27 observational studies, of which 23 were case-control studies, 3 cohort studies and one pooled analysis of prospective cohort studies, including a total of 16,554 epithelial ovarian cancer cases. We derived pooled meta-analytic estimates using random-effects models.

RESULTS

The pooled relative risk (RR) for any alcohol drinking compared with non/occasional drinking was 1.00 [95% confidence interval (CI), 0.95-1.05]. The RRs were 0.97 (95% CI, 0.92-1.02), 1.03 (95% CI, 0.96-1.11) and 1.09 (95% CI, 0.80-1.50) for light (≤ 1 drink/day), moderate (>1 to <3 drinks) and heavy drinking (≥ 3 drinks/day), respectively. In particular, the pooled RR for invasive epithelial ovarian cancers was 1.00 (95% CI, 0.95-1.06), while for borderline cancers was 0.96 (95% CI, 0.74-1.26). Stratified analyses across cancer histotypes revealed a modest protective effect of alcohol on endometrioid epithelial ovarian tumors (RR=0.82, 95% CI, 0.70-0.96), while no association was found for serous (RR=1.00, 95% CI, 0.84-1.19), mucinous (RR=0.91, 95% CI, 0.78-1.08) and clear cell (RR=0.93, 95% CI, 0.76-1.14) cancers. There was no evidence of publication bias.

CONCLUSIONS

This comprehensive meta-analysis provided no evidence of a material association between alcohol drinking and epithelial ovarian cancer risk.

Folate, vitamin B(6) , vitamin B(12) , methionine and alcohol intake in relation to ovarian cancer risk

Folate, methionine, vitamin B(6) and vitamin B(12) may influence carcinogenesis due to their roles in the one-carbon metabolism pathway, which is critical for DNA synthesis, methylation and repair. Low intake of these nutrients has been associated with an increased risk of breast, colon and endometrial cancers. Previous studies that have examined the relation between these nutrients and ovarian cancer risk have been inconsistent and have had limited power to examine the relation by histologic subtype. We investigated the association between folate, methionine, vitamin B(6) , vitamin B(12) and alcohol among 1910 women with ovarian cancer and 1989 controls from a case-control study conducted in eastern Massachusetts and New Hampshire from 1992 to 2008. Diet was assessed via food frequency questionnaire. Participants were asked to recall diet one-year before diagnosis or interview. Logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (95% CIs). We also examined whether the associations varied by ovarian cancer histologies using polytomous logistic regression. We observed an inverse association between dietary vitamin B(6) (covariate-adjusted OR = 0.76, 95% CI 0.64-0.92; p(trend) = 0.002) and methionine intake (covariate-adjusted OR = 0.72, 95% CI = 0.60-0.87; p(trend) < 0.001) and ovarian cancer risk comparing the highest to lowest quartile. The association with dietary vitamin B(6) was strongest for serous borderline (covariate-adjusted OR = 0.49, 95% CI = 0.32-0.77; p(trend) = 0.001) and serous invasive (covariate-adjusted OR = 0.74, 95% CI = 0.58-0.94; p(trend) = 0.012) subtypes. Overall, we observed no significant association between folate and ovarian cancer risk. One-carbon metabolism related nutrients, especially vitamin B(6) and methionine, may lower ovarian cancer risk.

Tea consumption and epithelial ovarian cancer risk: a systematic review of observational studies

Ovarian cancer is the seventh most common type of cancer in the United States and is often not diagnosed until late stages. Thus, identifying potential risk factors and prevention strategies is particularly important. This systematic review analyzes existing evidence on the association between tea consumption and epithelial ovarian cancer risk in human observational studies. PubMed was searched through September 30, 2010 for eligible articles; 16 articles met the inclusion criteria for this systematic review. Five studies found overall tea intake to be associated with a decreased epithelial ovarian cancer risk, 1 found a borderline decreased risk, 9 found no association, and 1 found a borderline increased risk. Overall, it does not appear that tea consumption increases risk of ovarian cancer, but there is insufficient evidence at this point to conclude that it is protective against ovarian cancer. Many of the studies included in this review had important limitations, especially related to the lack of detailed data collected on tea consumption. Further research is needed and should focus on more detailed assessment of type of tea consumed, frequency, and duration of tea intake. Future studies should also explore potential differences in the association between tea intake and ovarian cancer risk among subpopulations.

Green and black tea in relation to gynecologic cancers

SCOPE

Observational studies have evaluated the relationship between green tea intake and cancers of the ovary and endometrium, but we are not aware of the published studies on green tea intake and risk of human papillomavirus (HPV)-related cancers of the cervix, vagina, or vulva.

METHODS AND RESULTS

A critical review of the published literature on tea intake and risk of ovarian and endometrial cancers was conducted. In meta-analyses, we report inverse associations for green tea intake and risk of ovarian cancer (odds ratio [OR]=0.66; 95% confidence interval [CI]: 0.54, 0.80), and for green tea and risk of endometrial cancer (OR=0.78, 95% CI: 0.62, 0.98). There was no association for black tea and ovarian cancer risk (OR=0.94, 95% CI: 0.87, 1.02) and a positive association with endometrial cancer risk (OR=1.20, 95% CI: 1.05, 1.38). We summarized the experimental evidence supporting the antiviral and immunomodulatory activities of green tea catechins, and results from randomized clinical trials that demonstrated green tea catechin efficacy on treatment of cervical lesions and external genital warts.

CONCLUSION

Observational data support a protective role of green tea on risk of ovarian and endometrial cancers. Observational data are needed to evaluate whether green tea reduces risk of human papillomavirus-related cancers.

Wine drinking and epithelial ovarian cancer risk: a meta-analysis

OBJECTIVE

Wine has been the focus in the prevention of epithelial ovarian cancer (EOC) development because resveratrol abundant in wine has anti-carcinogenic properties. However, epidemiologic results have been heterogenous in the chemopreventive effect of wine on the development of EOC. Thus, we performed a meta-analysis for comparing EOC risk between wine and never drinkers using previous related studies.

METHODS

After extensive search of the literature between January 1986 and December 2008, we analyzed 10 studies (3 cohort and 7 case control studies) with 135,871 women, who included 65,578 of wine and 70,293 of never drinkers.

RESULTS

In all studies, there was no significant difference in EOC risk between wine and never drinkers (odds ratio [OR], 1.13; 95% confidence interval [CI], 0.92 to 1.38; random effects). When we performed re-analysis according to the study design, 3 cohort and 7 case control studies showed that there were also no significant differences in EOC risk between wine and never drinkers, respectively (OR, 1.44 and 1.04; 95% CI, 0.74 and 2.82 and 0.88 to 1.22; random effects). In sub-analyses using 2 case-control studies, EOC risk was not different between former and never drinkers (OR, 1.12; 95% CI, 0.87 to 1.44; fixed effect), and between current and former drinkers (OR, 0.74; 95% CI, 0.41 to 1.34; random effects).

CONCLUSION

Although resveratrol, abundantly found in wine, is a promising naturally occurring compound with chemopreventive properties on EOC in preclinical studies, this meta-analysis suggests the epidemiologic evidence shows no association between wine drinking and EOC risk.

Flavonoid intake and ovarian cancer risk in a population-based case-control study

Several recent studies have evaluated the association between dietary flavonoid intake and ovarian cancer risk, and all reported significant or suggestive inverse associations with certain flavonoids or flavonoid subclasses; however, most of these studies were small to moderate in size. We, therefore, examined this association in a large, population-based case-control study. We calculated intake of 5 common dietary flavonoids (myricetin, kaempferol, quercetin, luteolin, and apigenin), as well as total intake of these flavonoids, for 1,141 cases and 1,183 frequency-matched controls. We used unconditional logistic regression to estimate the relative risk (RR) of ovarian cancer for each quintile of flavonoid intake when compared with the lowest quintile. We did not observe an association between total flavonoid intake and ovarian cancer risk. The multivariable-adjusted RR for the highest versus lowest quintile of total flavonoid intake was 1.06 (95% confidence interval [CI] = 0.78-1.45). In analyses of each individual flavonoid, only intake of apigenin was associated with a borderline significant decrease in risk (RR, highest vs. lowest quintile = 0.79, 95% CI = 0.59-1.06; p-trend = 0.26), and this association was significant after adjustment for intake of the other 4 individual flavonoids (comparable RR = 0.72, 95% CI = 0.53-0.98; p-trend = 0.09). These results provide limited support for an association between flavonoid intake and ovarian cancer risk. However, given the findings of previous studies and the biologic plausibility of this association, additional studies are warranted.

Coffee and caffeine intake and the risk of ovarian cancer: the Iowa Women's Health Study

Laboratory data suggest that caffeine or some components of coffee may cause DNA mutations and inhibit tumor suppressor mechanisms, leading to neoplastic growth. However, coffee consumption has not been clearly implicated in the etiology of human postmenopausal ovarian cancer. This study evaluated the relationship of coffee and caffeine intake with risk of epithelial ovarian cancer in a prospective cohort study of 29,060 postmenopausal women. The participants completed a mailed questionnaire that assessed diet and health history and were followed for ovarian cancer incidence from 1986 to 2004. Age-adjusted and multivariate-adjusted hazard ratios were calculated for four exposure variables: caffeinated coffee, decaffeinated coffee, total coffee, and total caffeine to assess whether or not coffee or caffeine influences the risk of ovarian cancer. An increased risk was observed in the multivariate model for women who reported drinking five or more cups/day of caffeinated coffee compared to women who reported drinking none (HR = 1.81, 95% CI: 1.10-2.95). Decaffeinated coffee, total coffee, and caffeine were not statistically significantly associated with ovarian cancer incidence. Our results suggest that a component of coffee other than caffeine, or in combination with caffeine, may be associated with increased risk of ovarian cancer in postmenopausal women who drink five or more cups of coffee a day.

Coffee, tea, colas, and risk of epithelial ovarian cancer

Associations of coffee, tea, and other caffeinated beverages with ovarian cancer risk remain uncertain. In a population-based study in Washington State, 781 women with epithelial ovarian cancer diagnosed in 2002 to 2005 and 1,263 controls completed self-administered questionnaires detailing consumption of caffeinated and noncaffeinated coffee, teas, and colas and in-person interviews regarding reproductive and hormonal exposures. We assessed risk associated with coffee, tea, and cola drinking and with total caffeine consumption using logistic regression to calculate odds ratios and 95% confidence intervals. Neither caffeinated nor decaffeinated coffees were associated with ovarian cancer risk; also, we observed no association of total caffeine with risk using a combined index that summed intake from coffee, tea, and carbonated soft drinks. Among teas, neither herbal/decaffeinated nor black teas were associated with risk; however, women who reported drinking >or=1 cup/d of green tea had a 54% reduction in risk (P trend = 0.01). Associations of green tea with risk were similar when invasive and borderline cases were considered separately and when Asian women were excluded from analysis. Green tea, which is commonly consumed in countries with low ovarian cancer incidence, should be further investigated for its cancer prevention properties.

Caffeine, alcohol, smoking, and the risk of incident epithelial ovarian cancer

BACKGROUND

Smoking, caffeine, and alcohol intake are all potentially modifiable factors that have an unclear association with ovarian cancer risk. Therefore, the associations between these exposures and ovarian cancer risk were prospectively examined among 110,454 women in the Nurses' Health Study (NHS) for the smoking analyses and 80,253 women for the dietary analyses.

METHODS

Women completed biennial questionnaires assessing ovarian cancer risk factors beginning in 1976, with food frequency questionnaires administered every 2 to 4 years starting in 1980. For the smoking analyses, 737 confirmed cases of epithelial ovarian cancer were identified and for the dietary aims, 507 cases were identified through June 1, 2004.

RESULTS

Compared with never-smokers, neither current nor past smoking was associated with ovarian cancer risk overall; however, both were associated with mucinous tumors (n = 69; rate ratio [RR], past = 2.02 [95% confidence interval (CI), 1.15-3.55]; RR, current = 2.22 [95% CI, 1.16-4.24]). A modest inverse association between caffeine intake and ovarian cancer risk was observed (RR, top vs bottom quintile = 0.80; 95% CI, 0.60-1.07 [P = .03]), which was strongest for women who had never used either oral contraceptives (RR = 0.65; 95% CI, 0.46-0.92 [P for heterogeneity = .02]) or postmenopausal hormones (RR = 0.57; 95% CI, 0.36-0.91 [P for heterogeneity = .13]). Alcohol was not associated with ovarian cancer risk.

CONCLUSIONS

The results of the current study suggest that cigarette smoking may only increase the risk for mucinous ovarian tumors, and alcohol intake was not associated with risk. However, an inverse association was observed between caffeine intake and ovarian cancer risk, particularly in women not using hormones; this finding merits further study.

The association of tea consumption with ovarian cancer risk: A metaanalysis

OBJECTIVE

This metaanalysis was undertaken to evaluate the relationship between tea intake and ovarian cancer risk.

STUDY DESIGN

A systematic literature search up to September 2006 was performed in Medline, Embase, CANCERLIT, and the Cochrane Database. The summary relative risk was calculated. A sensitivity analysis was conducted to test the influence of each single study. Heterogeneity and publication bias were also evaluated.

RESULTS

Two cohort and 7 case-control studies were included. The combined relative risk did not show that tea consumption was associated with a reduced ovarian cancer risk (relative risk, 0.84; 95% confidence interval, 0.66-1.07). When the analyses were stratified into subgroups, there was no evidence that study design substantially influenced the estimate of effects. The sensitivity analysis which means removing one study at a time confirmed the stability of our results.

CONCLUSION

Our findings did not support that tea consumption was related to the decreased risk of ovarian cancer.

A prospective study of dietary flavonoid intake and incidence of epithelial ovarian cancer

Flavonoids are antioxidant compounds found in plants, including fruits, vegetables and tea. No prior prospective 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 (RR = 0.66, 95% CI = 0.49-0.91; p-trend = 0.01). There was evidence of an inverse association with consumption of tea (nonherbal) and broccoli, the primary contributors to kaempferol intake in our population. These data suggest that dietary intake of certain flavonoids may reduce ovarian cancer risk, although additional prospective studies are needed to further evaluate this association. If confirmed, these results would provide an important target for ovarian cancer prevention.

Tea and coffee drinking and ovarian cancer risk: results from the Netherlands Cohort Study and a meta-analysis

In a cohort study, ovarian cancer (280 cases) showed no significant association with tea or coffee, the multivariable rate ratios being 0.94 (95% confidence interval (CI): 0.89, 1.00) and 1.04 (95% CI: 0.97, 1.12) per cup per day, respectively. A meta-analysis also produced no significant findings overall, though the cohort studies showed a significant inverse association for tea.

Intake of coffee and tea and risk of ovarian cancer: a prospective cohort study

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 prospective studies of these associations. Therefore, we examined ovarian cancer risk in association with both coffee and tea intake in a prospective cohort study of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS) who completed a self-administered food frequency questionnaire between 1980 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending between 1998 and 2000. Data from the food frequency questionnaire 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 prospective studies.

Possible role for green tea in ovarian cancer prevention

Ovarian cancer is the leading cause of death from gynecologic cancer. Tea, especially green tea, has shown promise in the prevention of several cancers. Green tea contains a number of compounds, including polyphenols, that have chemopreventive properties. There is much evidence from in vitro and animal studies suggesting that components of tea are associated with decreased risk or progression of ovarian cancer. However, epidemiologic studies have generated inconsistent results. Recent research conducted in China reported reduced risk of ovarian cancer and increased survival post diagnosis with green tea consumption. This review presents emerging evidence and the authors' perspectives on the role of green tea in ovarian cancer prevention.

Wine and other alcohol consumption and risk of ovarian cancer in the California Teachers Study cohort

Objective

Whether alcohol consumption influences ovarian cancer risk is unclear. Therefore, we investigated the association between alcohol intake at various ages and risk of ovarian cancer.

Methods

Among 90,371 eligible members of the California Teachers Study cohort who completed a baseline alcohol assessment in 1995–1996, 253 women were diagnosed with epithelial ovarian cancer by the end of 2003. Multivariate Cox proportional hazards regression analysis was performed to estimate relative risks (RRs) and 95% confidence intervals (CIs).

Results

Consumption of total alcohol, beer, or liquor in the year prior to baseline, at ages 30–35 years, or at ages 18–22 years was not associated with risk of ovarian cancer. Consumption of at least one glass per day of wine, compared to no wine, in the year before baseline was associated with increased risk of developing ovarian cancer: RR = 1.57 (95% CI 1.11–2.22), P_trend = 0.01. The association with wine intake at baseline was particularly strong among peri-/post-menopausal women who used estrogen-only hormone therapy and women of high socioeconomic status.

Conclusions

Alcohol intake does not appear to affect ovarian cancer risk. Constituents of wine other than alcohol or, more likely, unmeasured determinants of wine drinking were associated with increased risk of ovarian cancer.

Consumption of black tea or coffee and risk of ovarian cancer

The goal of this study was to investigate the associations between ovarian cancer risk and usual consumption of black tea, regular coffee, or decaffeinated coffee. Using a hospital-based case–control design, participants included 414 women with primary epithelial ovarian, fallopian, or peritoneal cancer and 868 age- and region-matched women with nonneoplastic conditions. All participants completed a comprehensive epidemiologic questionnaire. Black tea consumption was associated with a linear decline in ovarian cancer risk (P for trend 0.03), with individuals consuming two or more cups daily experiencing a 30% decline in risk (adjusted OR 0.70, 95% CI 0.51–0.97). Similar declines were noted among individuals consuming two or more cups of decaffeinated coffee daily (adjusted OR 0.71, 95% CI 0.51–0.99; P for trend 0.002). However, no association was noted between any level of regular coffee consumption and risk of ovarian cancer. The chemoprotective effects of phytochemicals in black tea and decaffeinated coffee may be important, although the effects of phytochemicals in regular coffee may be counteracted by the elevated risk associated with its higher caffeine content.

The effect of lifestyle factors on gynaecological cancer

Several lifestyle factors affect a woman's risk of gynaecological cancer and-potentially-can be modified to reduce risk. This chapter summarises the evidence for the effect of lifestyle factors on the incidence of gynaecological malignancy. The incidence of obesity is increasing in the developed world such that it now contributes as much as smoking to overall cancer deaths. Women with a body mass index (BMI)>40 have a 60% higher risk of dying from all cancers than women of normal weight. They are also at increased risk from gynaecological cancer. Dietary factors significantly influence the risk of gynaecological cancer: fruit, vegetables and antioxidants reduce risk whereas high animal fat and energy intakes increase risk. Alcohol intake adversely affects breast cancer risk, possibly accounting for 4% of all breast cancers. Physical activity protects against ovarian, endometrial and postmenopausal breast cancer, independently of BMI. The oral contraceptive pill has a substantial and long-lasting effect on the prevention of ovarian and endometrial cancer and is one of the best examples of large-scale chemoprevention in the developed world. Childbearing is protective against ovarian, endometrial and breast cancer but increases the risk of cervical cancer. Smoking acts as a cofactor in cervical carcinogenesis and increases the risk of ovarian cancer, particularly mucinous tumours.

Alcohol consumption and ovarian cancer risk in a population-based case-control study

Alcohol consumption has been investigated as a possible risk factor for ovarian cancer in several epidemiological studies, with inconsistent findings. Recent studies have suggested that the association between alcohol consumption and ovarian cancer may vary according to histologic subtype of ovarian cancer and type of alcohol consumed (e.g., wine, beer, or liquor). We examined these associations in a population-based case-control study comprised of 762 incident cases of epithelial ovarian cancer and 6,271 population controls from Massachusetts and Wisconsin aged 40-79 years. Women reported their usual alcohol consumption as young adults (20-30 years of age) and in the recent past. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. There was no significant association of ovarian cancer with increasing alcohol consumption either during ages 20-30 years (p trend 0.42) or in the recent past (p trend 0.83). Regular drinking of beer (1 drink/day or more) during ages 20-30 (OR 1.55, 95% CI 1.07-2.26), though not liquor (OR 1.35, 95% CI 0.86-2.11) or wine (OR 0.99, 95% CI 0.49-2.00), was associated with a statistically significant increase in risk of invasive tumors, whereas no significant relationships were observed for recent drinking, regardless of alcohol type. The elevated risk for early adult regular drinking was confined to serous invasive tumors (OR 1.52, 95% CI 1.01-2.30), though results for other subtypes were based on sparse data and results were imprecise. In this study, neither total alcohol consumption as a young adult nor recently was associated with an increase in the risk of ovarian cancer.

Tea, hormone-related cancers and endogenous hormone levels

Tea is one of the most popular beverages consumed around the world, second only to water. There has been substantial interest in the potential role of tea in cancer prevention, particularly in respiratory and gastrointestinal tract cancers. Recent epidemiological data have linked tea intake to reduced risk of hormone-related cancers, including breast, ovarian and prostate cancers. Based on sparse data, there is suggestion that tea intake may influence circulating hormone levels, providing a plausible mechanism whereby tea intake may influence risk of hormone-related cancers. The major objectives of this paper are to review the epidemiological evidence on tea and risk of breast, ovarian, and prostate cancers as well as the human and non-human studies on tea and circulating hormone levels. We pay special attention to some of the limitations of the human studies and discuss future research needs.

Modification of N‐Acetyltransferases and Glutathione S‐Transferases by Coffee Components: Possible Relevance for Cancer Risk

Enzymes of xenobiotic metabolism are involved in the activation and detoxification of carcinogens and can play a pivotal role in the susceptibility of individuals toward chemically induced cancer. Differences in such susceptibility are often related to genetically predetermined enzyme polymorphisms but may also be caused by enzyme induction or inhibition through environmental factors or in the frame of chemopreventive intervention. In this context, coffee consumption, as an important lifestyle factor, has been under thorough investigation. Whereas the data on a potential procarcinogenic effect in some organs remained inconclusive, epidemiology has clearly revealed coffee drinkers to be at a lower risk of developing cancers of the colon and the liver and possibly of several other organs. The underlying mechanisms of such chemoprotection, modifications of xenobiotic metabolism in particular, were further investigated in rodent and in vitro models, as a result of which several individual chemoprotectants out of the >1000 constituents of coffee were identified as well as some strongly metabolized individual carcinogens against which they specifically protected. This chapter discusses the chemoprotective effects of several coffee components and whole coffee in association with modifications of the usually protective glutathione-S-transferase (GST) and the more ambivalent N-acetyltransferase (NAT). A key role is played by kahweol and cafestol (K/C), two diterpenic constituents of the unfiltered beverage that were found to reduce mutagenesis/tumorigenesis by strongly metabolized compounds, such as 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine, 7,12-dimethylbenz[a]anthracene, and aflatoxin B(1), and to cause various modifications of xenobiotic metabolism that were overwhelmingly beneficial, including induction of GST and inhibition of NAT. Other coffee components such as polyphenols and K/C-free coffee are also capable of increasing GST and partially of inhibiting NAT, although to a somewhat lesser extent.

Common risk factors of breast and ovarian cancer: recent view

Clinicians, epidemiologists, and public health specialists tend to examine breast and ovarian cancer separately. Although this seems fairly rational and expected, both malignancies are estrogen related and thus share many risk factors. In this review, we investigate the common familial, reproductive, anthropometric, nutritional, and lifestyle risk factors of breast and ovarian cancer. We believe that the parallel examination of the two cancer types could significantly contribute to an improved prevention of "gynecological cancer" as a whole.

Association of folate and alcohol with risk of ovarian cancer in a prospective study of postmenopausal women

Studies evaluating the association of ovarian cancer with alcohol intake are inconsistent, and few have evaluated this association in the context of folate consumption. Dietary folate and alcohol intakes and lifestyle and medical information were collected with self-administered questionnaires in 1986 from postmenopausal women aged 55-69 followed prospectively for 15 years for risk of epithelial ovarian cancer in the Iowa Women's Health Study. Among 27,205 eligible women free of baseline cancer, 147 incident epithelial ovarian cancer cases were identified by linkage to a cancer registry. Compared to the lowest quartile of total folate (food plus supplement) intake, the multivariable risk ratios (RR) for increasing quartiles were 1.0 (referent), 1.59, 1.24, 1.73 (95% confidence interval [CI], 0.90-3.33; p for trend, 0.20). Compared to non-drinkers, the RRs for increasing alcohol intake were 1.0 (referent), 0.78 for 0.01-3.9 g/d, 0.75 for 4.0-9.9 g/d and 0.58 for > or =10 g/d (95% CI, 0.30-1.11; p for trend, 0.08). Among women with alcohol intake > or =4 g/d compared to < 4 g/d, the apparent risk reduction was limited to those with total folate intake > or =331 microg/d (RR, 0.52; 95% CI, 0.22-1.19; p for interaction, 0.04) although this estimate was based on only seven cases. The association did not change appreciably when we excluded tumors of mucinous histology. These findings suggest that alcohol consumption is inversely related to postmenopausal ovarian cancer, and that the association of folate with ovarian cancer may vary by the amount of alcohol consumed.

Alcohol, Wine, and Risk of Epithelial Ovarian Cancer

Moderate alcohol intake can influence sex hormone levels and affect ovarian function as well as increasing breast cancer risk. This suggests that alcohol might also influence ovarian cancer risk. We have evaluated this among 696 Australian women with histologically confirmed epithelial ovarian cancer and 786 cancer-free control women, selected at random from the electoral roll. Sociodemographic information and a detailed reproductive history were collected in a face-to-face interview, and information about diet and alcohol consumption was obtained from a food frequency questionnaire. Logistic regression was used to calculate adjusted odds ratios (OR) and 95% confidence intervals (95% CI). Overall, 59% of women drank &lt;1 standard drink/week and only 5% of cases and 8% of controls drank an average of ≥2 standard drinks/day. Compared with nondrinkers, the OR for women who drank an average of ≥2 standard drinks/day was 0.49 (95% CI = 0.30–0.81). This effect did not vary for the different subtypes but was restricted to wine (OR = 0.56, 95% CI = 0.33–0.93 for ≥1 glass/day versus nondrinkers) with no effect for beer (OR = 1.26, 95% CI = 0.65–2.46) or sherry/spirits (OR = 1.07, 95% CI = 0.59–1.95). Combining our results with the six previous population-based studies gave a pooled OR of 0.72 (95% CI = 0.54–0.97) for the highest alcohol intake group versus nondrinkers. These data suggest that alcohol does not increase risk of ovarian cancer. In this Australian population, the inverse association with alcohol was due solely to wine consumption and so may be a consequence of antioxidants and/or phytoestrogens in wine rather than the alcohol itself.

Association of caffeine intake and CYP1A2 genotype with ovarian cancer

Coffee and caffeine consumption has been associated with ovarian cancer risk in several epidemiological studies. CYP1A2 is a key enzyme in the metabolism of coffee and in the activation of heterocyclic aromatic compounds that may be carcinogenic. Data from a preliminary investigation conducted in Hawaii of 164 epithelial ovarian cancer cases and 194 controls were used to examine the hypothesis that coffee and caffeine intake increases the risk of ovarian cancer and that these relations are modified by the CYP1A2 high-inducibility A/A genotype. A personal interview and blood specimen were collected in the subjects' homes. A significant positive trend (p = 0.02) in the odds ratios (ORs) was found with increasing intake of caffeine but not with tea or soda. Regular coffee drinkers were at significantly increased risk (OR = 1.8, 95% confidence interval, CI = 1.1-2.8) of ovarian cancer compared with women who did not drink regular coffee. Women with any CYP1A2 C allele were at similar risk of ovarian cancer (OR = 1.1, 95% CI = 0.7-1.7) compared with women with the A/A genotype. The associations of caffeine and coffee intake with risk were stronger among women with the A/A genotype than among women with any C allele. Somewhat stronger relations of coffee and caffeine intake to risk were found among women with cruciferous vegetable consumption above the median and among cases with mucinous histology. These preliminary data suggest a modest positive association of caffeine and coffee consumption with the OR for ovarian cancer that may be modified by CYP1A2 genotype and exposures, such as cruciferous vegetable consumption, that influence CYP1A2 expression.

Catechin content of 18 teas and a green tea extract supplement correlates with the antioxidant capacity

Our literature review of currently available data in the area of tea and cancer prevention demonstrated that there is more conclusive evidence for the chemopreventive effect of green tea compared with black tea. We suggest that this is due to a large variation of the flavanol content in tea, which is not taken into consideration in most of the epidemiological studies. It was the purpose of this study to determine the flavanol content of various teas and tea products and to correlate it with their radical scavenging activity. A modified oxygen radical absorbance capacity (ORAC) assay at pH 5.5 was utilized. The total flavavol content varied from 21.2 to 103.2 mg/g for regular teas and from 4.6 to 39.0 mg/g for decaffeinated teas. The ORAC value varied from 728 to 1686 trolox equivalents/g tea for regular teas and from 507 to 845 trolox equivalents/g for decaffeinated teas. There was a significant correlation of flavanol content to ORAC value (r = 0.79, P = 0.0001) for the teas and green tea extract. The large variation in flavanol content and ORAC value among various brands and types of tea provides critical information for investigators using tea in studies of nutrition and cancer prevention.