***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: Epidemiologic studies have focused on the association between diet and breast cancer with conflicting results . Whereas a majority of case-control studies indicate a role for the intake of total fat and saturated fat , most prospect i ve cohort studies either are negative or indicate very modest associations . Only a few authors have examined the role of meat intake in relation to breast cancer risk . The aim of this study was to examine the relation between risk of breast cancer and dietary intake of meat , animal products , fat , and protein .  Between 1985 and 1991 , we recruited 14,291 New York City women in a prospect i ve cohort study of endogenous hormones , diet , and cancer in which they reported on their recent diet using a food frequency question naire self-administered at enrollment . From the cohort , 180 invasive breast cancer cases diagnosed before December 1990 and five times as many controls , individually matched by age , calendar time at enrollment , menopausal status , and , if premenopausal , phase of menstrual cycle , were included in a nested case-control study . There was an evident increase in the relative risk ( RR ) of breast cancer for increasing consumption of meat . Women in the upper quintile of meat consumption , as compared with the lowest quintile , had an energy-adjusted RR of 1.87 ( 95 % confidence interval = 1.09–3.21 ) . There was a modest RR increase in the upper quintile of total and saturated fat and no apparent association for other types of fat , protein , dairy products , poultry , or fish . The study indicates that the elevated consumption of certain foods of animal origin , such as red meat , may be a factor in explaining the postulated role of diet in breast cancer etiology The International Agency for Research on Cancer ( WHO-IARC ) classified red meat and processed meat as probably carcinogenic and carcinogenic for humans , respectively . These conclusions were mainly based on studies concerning colorectal cancer , but scientific evidence is still limited for other cancer locations . In this study , we investigated the prospect i ve associations between red and processed meat intakes and overall , breast , and prostate cancer risk . This prospect i ve study included 61,476 men and women of the French NutriNet-Santé cohort ( 2009 - 2015 ) aged ≥35 y and who completed at least three 24 hrs dietary records during the first year of follow-up .  The risk of developing cancer was compared across sex-specific quintiles of red and processed meat intakes by multivariable Cox models . 1,609 first primary incident cancer cases were diagnosed during follow-up , among which 544 breast cancers and 222 prostate cancers . Red meat intake was associated with increased risk of overall cancers [ HRQ5vs . Q1 = 1.31 ( 1.10 - 1.55 ) , ptrend = 0.01 ) and breast cancer ( HRQ5vs . Q1 = 1.83 ( 1.33 - 2.51 ) , ptrend = 0.002 ] . The latter association was observed in both premenopausal [ HRQ5vs . Q1 = 2.04 ( 1.03 - 4.06 ) ] and postmenopausal women [ HRQ5vs . Q1 = 1.79 ( 1.26 - 2.55 ) ] . No association was observed  between red meat intake and prostate cancer risk . Processed meat intake was relatively low in this study ( cut-offs for the 5th quintile = 46 g/d in men and 29 g/d in women ) and was not associated with overall , breast or prostate cancer risk . This large cohort study suggested that red meat may be involved carcinogenesis at several cancer locations ( other than colon-rectum ) , in particular breast cancer . These results are consistent with mechanistic evidence from experimental studies Abstract Objective : We studied whether polymorphisms in N-acetyltransferase 1 and 2 and Glutathione S-transferase M1 and T1 genes modify the association between  meat consumption and breast cancer .  Methods : A nested case control was conducted in a Dutch prospect i ve cohort . Breast cancer cases ( 229 ) and controls ( 264 ) were frequency matched on age , town and menopausal status . Results : There is no relation between any type of meat consumption ( i.e. , total meat , processed meat , fresh meat , red meat and white meat ) and breast cancer risk . Neither presence of NAT1 or NAT2 rapid genotype , or GSTT1 null genotype , alone or in combination with meat consumption affects breast cancer risk . Absence of GSTM1 shows 46 % increased breast cancer risk ( OR = 1.46 ( 95 % confidence interval , 95 % CI = 1.02–2.09 ) ) . When stratifying according to combined ‘ GSTM1 genotype-meat consumption ’ categories , breast cancer risk is slightly increased with consumption of red meat both in women with genotype GSTM1 presence ( OR = 1.49 and 1.75 for intermediate and high versus low consumption ) and in GSTM1 null genotype ( OR = 1.18 and 1.02 ) . These increases are statistically not significant . In postmenopausal women a suggestion of an effect of red meat consumption is observed : effects are slightly stronger , although still not statistically significant and without a clear dose – response relation : OR = 1.79 ( 95 % CI = 0.92–3.50 ) and 1.46 ( 1.46 ( 95 % CI = 0.76–2.82 ) for intermediate and high compared to low red meat consumption respectively . Reliable evaluation of interaction is not possible due to the small number of cancers . Conclusion : GSTM1 null genotype increases breast cancer risk .  Red meat consumption slightly increases breast cancer risk , but the relation is not statistically significant and GSTM1 , NAT1 , NAT2 and GSTT1 polymorphisms do not modify this relation Breast cancer incidence rates more than double in Chinese women as they migrate from China to Hong Kong to the United States , suggesting that environmental factors contribute to the international variation in breast cancer incidence . Several dietary factors , which differ between the United States and the Chinese population , including intake of soy , meat , and fruits and vegetables , have been suggested to affect breast cancer risk . This report describes results from a case-control study of diet and risk of breast cancer nested in a r and omized trial of breast self exam in Shanghai , China . Participating breast cancer cases ( n = 378 ) and frequency age-matched controls ( n = 1,070 ) completed a comprehensive food frequency question naire and a risk factor question naire . After adjustment for age , total energy intake , and total years of breast-feeding , women in the highest quartile of fruit and vegetable intake ( > or = 3.8 servings/d ) were significantly less likely to have breast cancer ( odds ratio , 0.48 ; 95 % confidence interval , 0.29 - 0.78 ) as compared with women in the lowest quartile of intake ( < or = 2.3 servings/d ) . Egg consumption was also significantly inversely associated with risk of breast cancer ( odds ratio for > or = 6.0 eggs/wk versus < or = 2.0 eggs/wk is 0.56 ; 95 % confidence interval , 0.35 - 0.91 ) . There was no difference in soy consumption between cases and controls . None of the associations with a single botanical family explained the strong inverse relationship between fruits and vegetables and breast cancer risk . These results provide additional evidence in support of the important role of fruits and vegetables in breast cancer prevention Background : Epidemiological evidence on meat intake and breast cancer is inconsistent , with little research on potentially carcinogenic meat-related exposures . We investigated meat subtypes , cooking practice s , meat mutagens , iron , and subsequent breast cancer risk . Methods : Among 52 158 women ( aged 55–74 years ) in the Prostate , Lung , Colorectal , and Ovarian Cancer Screening Trial , who completed a food frequency question naire , 1205 invasive breast cancer cases were identified . We estimated meat mutagen and haem iron intake with data bases accounting for cooking practice s. Using Cox proportional hazards regression , we calculated hazard ratios ( HRs ) and 95 % confidence intervals ( CIs ) within quintiles of intake . Results : Comparing the fifth to the first quintile , red meat ( HR=1.23 ; 95 % CI=1.00–1.51 , P trend=0.22 ) , the heterocyclic amine ( HCA ) , 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline ( MeIQx ) , ( HR=1.26 ; 95 % CI=1.03–1.55 ; P trend=0.12 ) , and dietary iron ( HR=1.25 ; 95 % CI=1.02–1.52 ; P trend=0.03 ) were positively associated with breast cancer . We observed elevated , though not statistically significant , risks with processed meat , the HCA 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline ( DiMeIQx ) , mutagenic activity , iron from meat , and haem iron from meat . Conclusion : In this prospect i ve study , red meat , MeIQx , and dietary iron elevated the risk of invasive breast cancer , but there was no linear trend in the association except for dietary iron Recent studies suggest that elevated body iron levels may contribute to breast carcinogenesis ; however , epidemiologic evidence is lacking . We used data from a large cohort study of Canadian women to assess breast cancer in association with total iron and heme iron intake . Among 49,654 women ages 40 to 59 followed for an average of 16.4 years , we identified 2,545 incident breast cancer cases .  Data from a food frequency question naire administered at baseline were used to calculate  total dietary iron and heme iron intake . Using Cox proportional hazards models , we found no association of  iron or heme iron intake with risk of breast cancer overall , in women consuming 30 + g of alcohol per day , or in women who had ever used hormone replacement therapy . The present study offers no support for an association of  iron or heme iron intake with breast cancer risk or for a modification by iron of the effect of alcohol or estrogen . However , further cohort studies with repeated measurement of iron intake are warranted . ( Cancer Epidemiol Biomarkers Prev 2007;16(6):1306–8 Objective To investigate the association between dietary protein sources in early adulthood and risk of  breast cancer . Design Prospect i ve cohort study . Setting Health professionals in the United States . Participants 88 803 premenopausal women from the Nurses ’ Health Study II who completed a question naire on diet in 1991 . Main outcome measure Incident cases of invasive breast carcinoma , identified through self report and confirmed by pathology report . Results We documented 2830 cases of breast cancer during 20 years of follow-up . Higher intake of total red meat was associated with an increased risk of breast cancer overall ( relative risk 1.22 , 95 % confidence interval 1.06 to 1.40 ; Ptrend=0.01 , for highest fifth v lowest fifth of intake ) . However , higher intakes of poultry , fish , eggs , legumes , and nuts were not related to breast cancer overall . When the association was evaluated by menopausal status , higher intake of poultry was associated with a lower risk of breast cancer in postmenopausal women ( 0.73 , 0.58 to 0.91 ; Ptrend=0.02 , for highest fifth v lowest fifth of intake ) but not in premenopausal women ( 0.93 , 0.78 to 1.11 ; Ptrend=0.60 , for highest fifth v lowest fifth of intake ) . In estimating the effects of exchanging different protein sources , substituting one serving/day of legumes for one serving/day of red meat was associated with a 15 % lower risk of breast cancer among all women ( 0.85 , 0.73 to 0.98 ) and a 19 % lower risk among premenopausal women ( 0.81 , 0.66 to 0.99 ) . Also , substituting one serving/day of poultry for one serving/day of red meat was associated with a 17 % lower risk of breast cancer overall ( 0.83 , 0.72 to 0.96 ) and a 24 % lower risk of postmenopausal breast cancer ( 0.76 , 0.59 to 0.99 ) . Furthermore , substituting one serving/day of combined legumes , nuts , poultry , and fish for one serving/day of red meat was associated with a 14 % lower risk of breast cancer overall ( 0.86 , 0.78 to 0.94 ) and premenopausal breast cancer ( 0.86 , 0.76 to 0.98 ) . Conclusion Higher red meat intake in early adulthood may be a risk factor for breast cancer , and replacing red meat with a combination of legumes , poultry , nuts and fish may reduce the risk of breast cancer Summary The association between soya foods and  breast cancer  risk was investigated in a prospect i ve study of 34 759 women in Hiroshima and Nagasaki , Japan . Women completed dietary question naires in 1969–1970 and /or in 1979–1981 and were followed for incident breast cancer until 1993 . The analysis involved 427 cases of primary breast cancer in 488 989 person-years of observation .  The risk for breast cancer was not significantly associated with consumption of soya foods : for tofu , relative risks adjusted for attained age , calendar period , city , age at time of bombings and radiation dose to the breast were 0.99 ( 95 % 
    Output:
    
In the prospect i ve observational studies , high processed meat consumption was associated with increased breast cancer risk