The risk factors for breast cancer

The fortune factors for chest crabmeatINTRODUCTION embrace genus malignant neoplastic disease is the few unwashed type of genus genus Cancer among women in Malayansia with an over entirely geezerhood-standardized incidence (ASR) of 46.2 per 100,000 population 1. The incidence of teat crab louse differs among Malaysia states it is the most common cancer among women in Penang, followed by Sabah 2. However, on that point is no previous meditate on danger factors associated done in Penang before. Determining the stake factors of bosom cancer helps to identify women who may benefit most from screening or another(prenominal) preventive measures, also offers hopeful promise of modifying those factors, thus preventing thorax cancer occurrence.Many risk factors of breast cancer engage been launch and many of them have been recognized as established factors. Advancing age is one of the most important factors 3. Reproductive factors like timing of menarche and menopause , coincidence play a major role in breast cancer incidence 4, 5 . Also, lifestyle factors like intoxicant consumption 6-9, high up fat sustenance 10-14 and dope 15-17 have been identified by many studies as risk factors for breast cancer. This study aimed to determine the relationship surrounded by the socio-demographic factors, family history, reproductive factors, the life-style factors and immaterial factors with the occurrence of the breast cancer among the study population.MATERIAL AND METHODSStudy designA matched case-control study was conducted in Penang General Hospital, Penang Island, Malaysia among 20th November 2009 and 22th January 2010 using a standardized questionnaire that designed into ii languages English and Malay. Both cases and controls were matched by age group and ethnicity. Sample size was calculated according to that reported by CARIF-UM (Release tender Malaysian mamilla crabby person genic Study) which stated that 14% of breast cancer patients in Malaysia who have family history of breast cancer 18 and the relative risk for strong family history ranging from 2.5 to 4.5 19 , the minimum sample size was 149 patients per group.Ethical ApprovalOur study was approved by Clinical question Centre and Medical Research Ethic Committee of Ministry of Health Malaysia. Considering the ethical issues, written consent was signed by each case and verbal agreement for interview participation was obtained from all control subjects. All the personal information collected was considered confidential.Data CollectionThe cases were recruited from a convenience sample of prevalent breast cancer women who attended the oncology clinic, day-c are chemotherapy center, oncology ward, and the functional ward during the period of conducting this research. Women with confirmed diagnosis of breast cancer histologically regardless of the stage and met the following criteria above 20 years old, non-pregnancy, without any gynecologic problems (e.g., arti ficial menopause by hysterectomy), hormonal and psychological problems, were called for interview. Only one patient refused to participate. Our controls were non-breast cancer women who attended the outpatient clinics and outpatient pharmacy during the equivalent period. Women who are non-pregnant, matched by age group and ethnicity to the cases recruited, without any malignancies, gynological, hormonal and endocrine, and psychological problems are eligible to be our controls. Statistical AnalysisAll data entry and analyses were conducted using SPSS version 15 Microsoft program. Descriptive statistics including mean and standard deviations (SD) for continuous variables, frequencies and percentages for categorical variables were used to describe the study population. Crude ORs with 95% CI were calculated using simple logistical regression models that examined the stand between breast cancer status and risk factors. Significant supreme variables with P values RESULTSIn all, 300 wo men within two groups were interviewed cl women with breast cancer and 150 control women without breast cancer. The means SD age of cases and controls were 52.81 11.13 years (range 23-83 years) and 52.40 11.52 years (range 22-78 years), respectively. Statistically, there is no world-shaking difference between cases and controls in term of age (P value= 0.75) and race frequency (P value= 1.00). Among each cases and controls group, 34.7 % were Malay, 50.7 % were Chinese, 14.0 % were Indian and 0.7 % were other races.Socio-demographic take a chance FactorsThe results of socio-demographic risk factors obtained from univariate logistic regression psychoanalysis summarized in Table 1 showed that lower educational aim and occupation were significantly link up to breast cancer risk (P Family HistoryFamily history of commencement exercise degree relative with other types of cancer (nasopharyngeal, ovarian, Lung, bladder, stomach, or colon cancers) change magnitude the risk signific antly (P Reproductive find FactorsAccording to the reproductive factors (Table 3), women with late ages at menopauses (= 55 years old) (OR=2.8, 95%CI 1.18 6.67), or history of menstrual impairment (OR= 3.2, 95%CI 1.00 10.08) or who had neer breastfed (OR= 1.74, 95%CI= 1.09 2.76) were more than likely to have breast cancer. The evasive effect of breastfeeding erect to be a du balancen dependent women who had breastfed for only few months had a higher(prenominal) risk by 1.51 ( 95%CI 0.83 2.77) compared to breastfed women for a total of more than 1 year, and the risk additiond in non-breastfed women to 2.08 (95%CI= 1.22 3.57). Nevertheless, no statistically significant association were observed between breast cancer and the age at menarche, number of children (parity), age at first full term pregnancy, number of abortions and menopausal status. tone Style and External risk of exposure FactorsBreast cancer risk ratios were higher for women who had a history of benign bre ast disease (OR=2.8, 95%CI 1.13 6.88) and who had neer practiced low fat forage (white meat, white fish, skinless chicken and avoid deep fried intellectual nourishment) (OR=1.81, 95%CI 1.14 2.86). However, other lifestyle factors like smoking, alcoholic drink consumption, body mass index (BMI = 25 kg/m2) and external hormone use, like OCP and HRT were not significant statistically to be risks for breast cancer.multivariate ResultsAmong all factors included in the multivariable model (Table 5), occupation, breastfeeding and practicing low-fat diet play important protective roles against breast cancer unemployed women ( change OR= 2.7, 95%CI 1.59 4.61), never breastfed women (adjusted OR= 1.94, 95%CI 1.15 3.27) and never practiced low-fat diet (adjusted OR = 1.97, 95%CI 1.18 3.27) were found to be associated with breast cancer risk as statistically significant independent factors.Other factors contributing to breast cancer risk were family history of distant relatives with br east cancer (adjusted OR= 3.70, 95%CI 1.48 -9.20) and first degree relatives with other cancers (adjusted OR= 5.27, 95%CI 1.38 20.1). Also, women with histories of benign breast disease (adjusted OR= 3.14, 95%CI 1.17 8.40) and menstrual cycle irregularity (adjusted OR= 4.94, 95% CI 1.42 17.26) were more likely to have breast cancer. OCP use was significantly related to breast cancer risks however, this was not related to the duration. maculation using OCP for 5 years increased the risk by only 3 times (95% CI 1.02 9.00).DISCUSSIONIn a pooled analysis of 150 breast cancer cases and 150 non-breast cancer controls, associations between breast cancer and various demographic, reproductive, and lifestyle factors were examined. Both cases and controls were chosen intentionally from the same hospital during the same study period.The risk of breast cancer has been reported to be associated with socio-demographic status 24-26. Age is a very important risk factor it was found that breast cancer incidence generally increases with age. The mean age at diagnosis for all breast cancer patients is 50.7 11.0 years. The peak age reaches between 40 and 49 and thereafter the number of breast cancer patients decreases quite dramatically with only 4.0% above 70 years old (Figure 1). Also, only 2.0% of cases were diagnosed below the age of 30 which is consistent with Singletary pictureings 3.According to the other socio-demographic factors studied, higher take of education has a protective effect (POccupation status also plays an important role as a protection factor against breast cancer in both univariate and multivariate analysis (P Family history is an important factor in our population an adjusted OR of 3.7 (95%CI = 1.48 9.2) was found for women with a distant relative with breast cancer, which is within the OR range reported by previous literature 19, 37 and higher than that reported by others 3, 38. However, having first degree-relatives with breast cancer is not si gnificantly related to the breast cancer risk (P 0.05). This may be explained partially because of the high frequency of controls (7 of 150 controls vs. 16 of 150 cases) that had first-degree relatives with breast cancer. Such a high number of family histories in controls may result in an down the stairsestimation of increased risk due to the family history.Furthermore, history of first degree relatives with other cancer (gastric, pancreatic, colon, lung carcinoma.etc) is significantly more frequent in patients than in controls with the adjusted odd ratio of 5.27 (95% CI= 1.38 20.1). Recently, it has been discovered that clustering of first degree cases of breast, pancreas and stomach carcinomas in a family has been associated with mutations in the breast cancer susceptibility gene BRCA2 39.Breastfeeding is an important protective factor among our population women who had never breastfed their baby have a 1.74 (95%CI 1.09 2.76) higher risk of get breast cancer and the adjusted odd ratio is 1.94 (ever versus never, 95%CI = 1.15 3.27) in the multivariate analysis. Our visualiseing is in agreement with these studies 40-48, however, others failed to find any association 31, 36, 49-52.Moreover, the duration of breastfeeding has also an important effect found that the longer the lactation period, the least the risk of breast cancer. This inverse relationship between the duration of breastfeeding and the risk of breast cancer have been suggested by other studies 46, 53-60, however, other revealed that this is mainly confined to women diagnosed before the age of 40 with a gutless trend for older patients 61.History of irregular menstrual cycle (Polymenorrhea, Oligomenorrhea, or Amenorrhea) had an increased risk the OR range (3.17- 4.94) and this supports the Turkish study 62 which found that menstrual irregularity increased the risk by 1.61 (95% CI 1.05-2.49). Others 55, 63, 64 did not find any significant relation between menstrual irregularity and breast can cer risk. However, it has been reported that menstrual irregularity decreased the risk 65This study sight a significant association between oral contraceptive use and breast cancer, consistent with other local studies 27, 36, 66 and other international studies 46, 67. Whereas we could not find any relationship between the duration of OCP used and the risk of breast cancer, so our study does not support the growing body of evidence that long use of oral contraceptives, especially during certain parts of reproductive life, is associated with a modest increase in breast cancer risk 46, 68. However, most studies found no or weak association of OCP use with the risk of breast cancer 34, 69-71. The association between OCP use and breast cancer is also related to the duration, dosage, type of OCP and the age of first use 72.Previous history of benign breast disease is highly significant in the present study (P Practicing low-fat diet (take only white meat, white fish, and skinless chicke n and avoid deep fried food) exhibited an inverse association with the risk of breast cancer, which is significant in both univariate and multivariate analysis (crude OR 1.81, 95%CI= 1.14 2.86) and (adjusted OR 1.96, 95%CI=1.18 3.27) respectively for women who had never practicing low fat diet. Red and fried meat consumption and fatty foods were suggested as important risk factors for breast cancer 11, 73. For each additional 100 g (3.5 oz) daily of meat consumption the risk of breast cancer increased risk by 56% in a French case-control study 13. Another age group study 74 reported a significant relative risk (RR) of 1.7 for women who reported eating the skin on poultry. Null high consumptions of fatty forms, namely fried fish and chicken with skin were associated with an increase of breast cancer risk 75. Other case-control studies reported a protective effect of poultry and fish against the development of breast cancer 76. Also, there was no evidence for a positive association between total dietetic fat inspiration and risk of breast cancer and no reduction in the risk even among women whose energy intake from fat was less than 20 percent of the total energy intake 77. Some case-control studies and cohort studies have shown weak and inconsistent associations between high intake of dietary fat and poultry with the occurrence of breast cancer 14, 78.Other well-established factors that have been studied smoking cigarettes, alcohol intake, regular use of HRT, pre and post-menopausal body mass index (BMI), marital status and the level of monthly income , age at menarche, age at first full term pregnancy, number of abortions, menopausal status and parity were found not to be significant in this study (P 0.05).Strength and LimitationTo our own knowledge, the present study is the first case-control study of breast cancer to investigate the risk factor in Penang Island, Malaysia. Both cases and control were matched by age group and ethnicity which add some st rength to our study. This research studied almost all the socio-demographic, reproductive, lifestyle and external risk factors, so the confounding effects of all of these factors had been taken into consideration when getting our result by multivariate analysis. Furthermore, the questionnaire was designed into two languages (English and Malay), hence most of the three main ethnic groups in Penang (Chinese, Malay, and Indian) are fluent in both or both of them.As other case-control studies, our work has some limitations. The question regarding menstrual history (age at menarche, age at menopause) of the respondent are likely to be affected by recall bias. There was a chance of error in recall especially for age at menarche that had been many decades previous and this may have affected the results. We tried to minimize this bias through assisting the memory of subjects.Some of the Chinese cases were excluded due to the language barrier (they cannot speak Malay or English), that may cause some selection bias. Finally, generalizability of our findings may be precluded by our population features they have high mean ages, low educational level and belong to a mid socioeconomic class, also by the difference in the ethnicity distribution among different Malaysia states.CONCLUSIONIn summarily, family history with breast cancer or other cancer, history of benign breast disease, menstrual irregularity, and oral contraceptive used were found to be significantly associated with increased breast cancer risk, whereas breastfeeding, occupation and practicing low fat diet have protective effects against breast cancer. Late age at menopause and education level are significant risk factor only in the univaraite analysis.REFERENCESLim, G. and Y. Halimah, Second report of the national cancer registry cancer incidence in Malaysia 2003. National cancer Registry, Ministry of Health, Malaysia, 2004.Rosemawati, A. and A. Sallehudin, pubic louse registration in Malaysia. Asian Pacif ic J Cancer Prev, 2001. 2 p. 43-5.Singletary, S., Rating the risk factors for breast cancer. Annals of surgery, 2003. 237(4) p. 474.Jogahana, H., et al., Serum Prolactin Levels and Risk Factors of Breast Cancer in Postmenopausal Japanese Women. Acta Sch Med Univ Gifu, 2002. 50 p. 77-82.Noor, L. and H. Ismail, Serum Selenium Level and Other Risk Factors for Breast Cancer among Patients in a Malaysian Hospital. Environmental health and preventive medicine, 2007. 12(3).Brown, L., Low level alcohol intake, cigarette smoking and risk of breast cancer in Asian-American women Breast Cancer Res Treat, 2009. 10.Kropp, S., et al., Low-to-moderate alcohol consumption and breast cancer risk by age 50 years among women in Germany. American diary of Epidemiology, 2001. 154(7) p. 624.Stoll, B., Alcohol intake and late-stage promotion of breast cancer. European journal of Cancer, 1999. 35(12) p. 1653-1658.Zaridze, D., et al., Diet, alcohol consumption and reproductive factors in a case-control stu dy of breast cancer in Moscow. Int J Cancer, 1991. 48(4) p. 493-501.Stoll, B., Breast cancer and the western diet role of fatty acids and antioxidant vitamins. European Journal of Cancer, 1998. 34(12) p. 1852-1856.De Lima, F., Diet and cancer in Northeast Brazil evaluation of eating usances and food group consumption in relation to breast cancer. Cad Saude Publica, 2008. 24(4) p. 820-8.Jarvinen, R., et al., Diet and breast cancer risk in a cohort of Finnish women. Cancer letters, 1997. 114(1-2) p. 251-253.Wakai, K., et al., Dietary intakes of fat and fatty acids and risk of breast cancer a prospective study in Japan. Cancer science, 2005. 96(9) p. 590-599.Hunter, D. and W. Willett, Diet, body build, and breast cancer. Annual reexamination of nutrition, 1994. 14(1) p. 393-418.Bennicke, K., et al., Cigarette smoking and breast cancer. British Medical Journal, 1995. 310(6992) p. 1431.Ha, M., et al., Smoking cigarettes before first childbirth and risk of breast cancer. American Journa l of Epidemiology, 2007.Terry, P., A. Miller, and T. Rohan, Cigarette smoking and breast cancer risk a long latency period? planetary Journal of Cancer, 2002. 100(6) p. 723-728.CARIF-UM, CARIF-UM Release naked Malaysian Breast Cancer Genetic Study Kuala Lumpur, Cancer Research Initiatives Foundation (CARIF) and University Malaya (UM), 2008.Weir, R., P. Day, and W. Ali, Risk factors for breast cancer in women. A systematic review of the literature. New Zealand Health Technology judging Report, 2007. 10(2).Mickey, R. and S. Greenland, The impact of confounder selection criteria on effect estimation. American Journal of Epidemiology, 1989. 129(1) p. 125.Maldonado, G. and S. Greenland, Simulation study of confounder-selection strategies. American Journal of Epidemiology, 1993. 138(11) p. 923.Greenland, S., Invited commentary variable selection versus shrinkage in the control of multiple confounders. American Journal of Epidemiology, 2008.Dales, L. and H. URY, An improper use of stati stical significance testing in studying covariables. International journal of epidemiology, 1978. 7(4) p. 373.Bala, D., et al., Role of dietary intake and biomarkers in risk of breast cancer a case control study. Asian Pac J Cancer Prev, 2001. 2 p. 123-30.Yavari, P., M. Mosavizadeh, and B. Sadrol-Hefazi, Reproductive Characteristics and the Risk of Breast Cancer-A Case-control Study in Iran. Asian Pacific Journal of Cancer Prevention, 2005. 6 p. 370-375.Finney Rutten, L. and R. Iannotti, Health beliefs, salience of breast cancer family history, and involvement with breast cancer issues adherence to annual mammography screening recommendations. Cancer Detection and Prevention, 2003. 27(5) p. 353-359.Daud, N.A., A Study of Risk Factors of Breast Cancer among Registered Female Patient in Kuala Lumpur Hospital between JULY 2001 TO SEPTEMBER 2001. NCD Malaysia, 2004. 3 p. 29-34.Ozmen, V., et al., Breast cancer risk factors in Turkish women a University Hospital based nested case control study. World Journal of functional Oncology, 2009. 7(1) p. 37.Jayalekshmi, P., S. Varughese, and M. Kalavathi, A Nested Case-Control Study of Female Breast Cancer in Karunagappally age bracket in Kerala, India. Asian Pacific Journal of Cancer Prevention, 2009. 10 p. 241-246.Helmrich, S., et al., Risk factors for breast cancer. American Journal of Epidemiology, 1983. 117(1) p. 35.Negri, E., et al., suckling and the risk of breast cancer in an Italian population. International Journal of Cancer, 1996. 67(2) p. 161-164.Tavani, A., et al., Risk factors for breast cancer in women under 40 years. European Journal of Cancer, 1999. 35(9) p. 1361-1367.Naieni, K., et al., Risk factors of breast cancer in north of Iran a case-control in Mazandaran Province. Asian Pacific Journal of Cancer Prevention, 2007. 8(3) p. 395.Ebrahimi, M., M. Vahdaninia, and A. Montazeri, Risk factors for breast cancer in Iran a case-control study. Breast Cancer Res, 2002. 4(5) p. R10.Morabia, A., et al., Breast can cer and active and passive smoking the role of the N-acetyltransferase 2 genotype. American Journal of Epidemiology, 2000. 152(3) p. 226.Norsa adah, B., et al., Risk factors of breast cancer in women in Kelantan, Malaysia. Singapore medical journal, 2005. 46(12) p. 698.Viladiu, P., et al., A breast cancer case-control study in Girona, Spain. Endocrine, familial and lifestyle factors. European Journal of Cancer Prevention, 1996. 5(5) p. 329.Pharoah, P., et al., Family history and the risk of breast cancer a systematic review and meta-analysis. International Journal of Cancer, 1997. 71(5) p. 800-809.Schubert, E., et al., BRCA2 in American families with four or more cases of breast or ovarian cancer recurrent and novel mutations, variable expression, penetrance, and the possibility of families whose cancer is not attributable to BRCA1 or BRCA2. American journal of human genetics, 1997. 60(5) p. 1031.Lubin, J., et al., Risk factors for breast cancer in women in northern Alberta, Canada, as related to age at diagnosis. Journal of the National Cancer Institute, 1982. 68(2) p. 211.Layde, P., et al., The independent associations of parity, age at first full term pregnancy, and duration of breastfeeding with the risk of breast cancer. J Clin Epidemiol, 1989. 42(10) p. 963-73.Brinton, L., et al., Breastfeeding and breast cancer risk. Cancer Causes and Control, 1995. 6(3) p. 199-208.Bernstein, L., Breastfeeding Experience and Breast Cancer Risk among Postmenopausal Women. Cancer Epidemiol Biomarkers Prev, 1998. 7 p. 365-369.Newcomb, P., et al., Lactation in relation to postmenopausal breast cancer. American Journal of Epidemiology, 1999. 150(2) p. 174.Furberg, H., et al., Lactation and breast cancer risk. International journal of epidemiology, 1999. 28(3) p. 396.Wang, Q., et al., A case-control study of breast cancer in Tianjin, China. Cancer Epidemiology Biomarkers Prevention, 1992. 1(6) p. 435.AL-Shaibani, H., et al., Risk Factors of Breast Cancer in Kuwait Case-contr ol Study. IRANIAN JOURNAL OF medical SCIENCES (IJMS), 2006. 31(2) p. 61-64.Calderin-Garcidueias, A., et al., Risk factors of breast cancer in Mexican women. Salud p?blica de Mxico, 2000. 42 p. 26-33.Ramon, J., et al., Age at first full-term pregnancy, lactation and parity and risk of breast cancer a case-control study in Spain. European journal of epidemiology, 1996. 12(5) p. 449-453.Magnusson, C., et al., The role of reproductive factors and use of oral contraceptives in the aetiology of breast cancer in women aged 50 to 74 years. International Journal of Cancer, 1999. 80(2) p. 231-236.Sikind, V., et al., Breast cancer and breastfeeding results from an Australian case-control study. American Journal of Epidemiology, 1989. 130(2) p. 229.Lai, F., et al., A case-control study of parity, age at first full-term pregnancy, breast feeding and breast cancer in Taiwanese women. Proceedings of the National Science Council, Republic of China. Part B, Life sciences, 1996. 20(3) p. 71.Byers, T. , et al., Lactation and Breast Cancer Evidence for a Negatwe Association in Premenopausal Women. American Journal of Epidemiology, 1985. 121(5) p. 664.Mctiernan, A. and D. Thomas, Evidence for a protective effect of lactation on risk of breast cancer in young women results from a case-control study. American Journal of Epidemiology, 1986. 124(3) p. 353.Yoo, K., et al., ORIGINAL CONTRIBUTIONS Independent Protective Effect of Lactation against Breast Cancer A Case-Control Study in Japan. American Journal of Epidemiology, 1992. 135(7) p. 726.Yuan, J., et al., Risk factors for breast cancer in Chinese women in Shanghai. Cancer research, 1988. 48(7) p. 1949.Tao, S., et al., Risk factors for breast cancer in Chinese women of Beijing. International Journal of Cancer, 1988. 42(4) p. 495-498.Gilliland, F., et al., Reproductive risk factors for breast cancer in Hispanic and non-Hispanic white women the New Mexico Womens Health Study. American Journal of Epidemiology, 1998. 148(7) p. 683.Romie u, I., et al., Breast cancer and lactation history in Mexican women. American Journal of Epidemiology, 1996. 143(6) p. 543.Newcomb, P., et al., Lactation and a reduced risk of premenopausal breast cancer. New England Journal of Medicine, 1994. 330(2) p. 81.Tryggvadottir, L., et al., Breastfeeding and reduced risk of breast cancer in an Icelandic cohort study. American Journal of Epidemiology, 2001. 154(1) p. 37.Kuru, B., et al., Risk Factors for Breast Cancer in Turkish Women with Early Pregnancies and Long-lasting Lactation. Acta oncologica, 2002. 41(6) p. 556-561.Talamini, R., et al., The role of reproductive and menstrual factors in cancer of the breast before and after menopause. European Journal of Cancer, 1996. 32(2) p. 303-310.Adebamowo, C. and O. Adekunle, Case-controlled study of the epidemiological risk factors for breast cancer in Nigeria. British Journal of Surgery, 1999. 86(5) p. 665-668.Vecchia, C., et al., General epidemiology of breast cancer in northern Italy. Inter national journal of epidemiology, 1987. 16(3) p. 347.Lokman, R., et al., Selenium blood level and other risk factors of breast cancer among patients in HKL, in National public Health Qolloquium, M.F.U. Cpmmunity Health Department, Editor. 2001 Kuala Lumpur.Brinton, L., et al., Modification of oral contraceptive relationships on breast cancer risk by selected factors among younger women. Contraception, 1997. 55(4) p. 197-203.Pike, M., et al., Hormonal risk factors,breast tissue age and the age-incidence of breast cancer. 1983.Marchbanks, P., et al., spoken contraceptives and the risk of breast cancer. The New England journal of medicine, 2002. 346(26) p. 2025.Malone, K., J. Daling, and N. Weiss, Oral contraceptives in relation to breast cancer. Epidemiol Rev, 1993. 15(1) p. 80-97.Vessey, M. and R. Painter, Oral contraceptive use and cancer. Findings in a large cohort study, 1968-2004. British journal of cancer, 2006. 95(3) p. 385.McPherson, K., C. Steel, and J. Dixon, ABC of breast diseases Breast cancerepidemiology, risk factors, and genetics. British Medical Journal, 2000. 321(7261) p. 624.Ronco, A., et al., Meat, fat and risk of breast cancer a case-control study from Uruguay. International Journal of Cancer, 1996. 65(3) p. 328-331.Byrne, C., G. Ursin, and R. Ziegler, A comparison of food habit and food frequency data as predictors of breast cancer in the NHANES I/NHEFS cohort. Journal of Nutrition, 1996. 126(11) p. 2757.Ronco, A., E. De Stfani, and A. Fabra, White meat intake and the risk of breast cancer a case-control study in Montevideo, Uruguay. Nutrition Research, 2003. 23(2) p. 151-162.Franceschi, S., A. Favero, and C. La Vecchia, Influennce of food groups and food diversity on breast cancer risk in Italy Int J Cancer, 1995. 63(6) p. 785-789.Hunter, D., et al., Cohort studies of fat intake and the risk of breast cancera pooled analysis. New England Journal of Medicine, 1996. 334(6) p. 356.Toniolo, P., et al., Consumption of meat, animal products, pro tein, and fat and risk of breast cancer a prospective cohort study in New York. Epidemiology, 1994 p. 391-397.