In this report, we examined the relationship between mother’s breastfeeding history and her risk of breast cancer, in a case–control study in Tunisia between 2006 and 2009. About 400 breast cancer cases and 400 controls were included. Cases and controls were interviewed using a standardized structured questionnaire to obtain information on breastfeeding and other risk factors. Mean duration of breastfeeding per child was significantly associated with a reduced risk of breast cancer for women who breastfed for >24 months per child. The OR was 0.46 (95% CI, 0.28–0.76) when compared those who breastfed for <6 months. The test for trend was significant (p = 0.01). A significantly reduced risk of breast cancer was found for those whose lifetime duration of breastfeeding was 73–108 months (OR = 0.65, 95% CI, 0.36–1.18) and for those who breastfed for ≥109 months (OR = 0.42, 95% CI, 0.20–0.84). Stratification by menopausal status showed a reduced risk of breast cancer associated with a longer duration of breastfeeding for both pre- and postmenopausal women. The risk reduction was more consistent for lifetime duration of breastfeeding, the test for trend being significant for both pre- (p = 0.03) and postmenopausal (p = 0.01) women. These results support an inverse association between breastfeeding and breast cancer risk.
Breast cancer Breastfeeding Case–control study
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This work was supported by the research unit “oncogénétique clinique” University of Medicine of Sousse. We would like to thank Mrs Kassab Asma for English revision.
Stewart SL, King JB, Thompson TD, Friedman C, Wingo PA (2004) Cancer mortality surveillance—United States, 1990–2000. MMWR Surveill Summ 53:1–108PubMedGoogle Scholar
Ben Ahmed S, Aloulou S, Bibi M et al (2002) Breast cancer detection in Tunisian women: an analysis of a hospital trial involving 729 patients. Santé Publique 14:231–241CrossRefPubMedGoogle Scholar
Collaborative Group on Hormonal Factors in Breast Cancer (2002) Breast cancer and breastfeeding: collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries, including 50302 women with breast cancer and 96973 women without the disease. Lancet 360:187–195CrossRefGoogle Scholar
Katsouyanni K, Lipworth L, Trichopoulou A et al (1996) A case-control study of lactation and cancer of the breast. Br J Cancer 73:814–818PubMedGoogle Scholar
Freudenheim JL, Marshall JR, Vena JE et al (1997) Lactation history and breast cancer risk. Am J Epidemiol 146:932–938PubMedGoogle Scholar
Newcomb PA, Egan KM, Titus-Ernstoff L et al (1999) Lactation in relation to postmenopausal breast cancer. Am J Epidemiol 150:174–182PubMedGoogle Scholar
Brinton LA, Potischman NA, Swanson CA et al (1995) Breast-feeding and breast cancer risk. Cancer Causes Control 6:199–208CrossRefPubMedGoogle Scholar
Romieu I, Hernandez-Avila M, Lazcano E et al (1996) Breast cancer and lactation history in Mexican women. Am J Epidemiol 143:543–552PubMedGoogle Scholar
Zheng T, Li D, Liu Y et al (2000) Lactation reduces breast cancer risk in Shandong Province, China. Am J Epidemiol 152:1129–1135CrossRefPubMedGoogle Scholar
Zheng T, Holford TR, Mayne ST et al (2001) Lactation and breast cancer risk: a case–control study in Connecticut. Br J Cancer 84(11):1472–1476CrossRefPubMedGoogle Scholar
Yang L, Jacobsen KH (2008) A systematic review of the association between breastfeeding and breast cancer. J Womens health (Larchmt) 17(10):1635–1645CrossRefGoogle Scholar
SAS Institute (1990) SAS/STAT user’s guide. Version 6. SAS Institute, Cary, NCGoogle Scholar
Alaya NB, Bouguerra LM, Trabelsi S, Zouari B (2002) Determinants of breastfeeding in a suburban area of Tunisia. Lettres à la rédaction/Archives de Pédiatrie 9:1112–1113Google Scholar
Stuver SO, Hsieh CC, Butone E, Trichopoulos D (1997) The association between lactation and breast cancer in an international case-control study: a re-analysis by menopausal status. Int J Cancer 71:166–169CrossRefPubMedGoogle Scholar
Gao Y-T, Shu X-O, Daí Q et al (2000) Association of menstrual and reproductive factors with breast cancer risk: results from the Shanghai breast cancer study. Int J Cancer 87:295–300CrossRefPubMedGoogle Scholar
Mahouri K, Dehghani Zahedani M, Zare S (2007) Breast cancer risk factors in south of Islamic Republic of Iran: a case–control study. East Mediterr Health J 13(6):1265–1273PubMedGoogle Scholar
Minami Y, Ohuchi N, Fukao A, Hisamichi S (2000) Determinants of infant feeding method in relation to risk factors for breast cancer. Prev Med 30(5):363–370CrossRefPubMedGoogle Scholar
Rosenberg L, Zhang Y, Coogan PF, Strom BL, Palmer JR (2009) A case–control study of oral contraceptive use and incident breast cancer. Am J Epidemiol 169:473–479CrossRefPubMedGoogle Scholar