Parity and breastfeeding are protective against breast cancer in Nigerian women

D Huo, C A Adebamowo, T O Ogundiran, E E Akang, O Campbell, A Adenipekun, S Cummings, J Fackenthal, F Ademuyiwa, H Ahsan, O I Olopade, D Huo, C A Adebamowo, T O Ogundiran, E E Akang, O Campbell, A Adenipekun, S Cummings, J Fackenthal, F Ademuyiwa, H Ahsan, O I Olopade

Abstract

As the relation between reproductive factors and breast cancer risk has not been systematically studied in indigenous women of sub-Saharan Africa, we examined this in a case-control study in Nigeria. In-person interviews were conducted using structured questionnaires to collect detailed reproductive history in 819 breast cancer cases and 569 community controls between 1998 and 2006. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI). Compared with women with menarcheal age<17 years, the adjusted OR for women with menarcheal age>or=17 years was 0.72 (95% CI: 0.54-0.95, P=0.02). Parity was negatively associated with risk (P-trend=0.02) but age at first live birth was not significant (P=0.16). Importantly, breast cancer risk decreased by 7% for every 12 months of breastfeeding (P-trend=0.005). It is worth noting that the distribution of reproductive risk factors changed significantly from early to late birth cohorts in the direction of increasing breast cancer incidence. Our findings also highlight the heterogeneity of breast cancer aetiology across populations, and indicate the need for further studies among indigenous sub-Saharan women.

References

    1. Adebamowo CA, Famooto A, Ogundiran TO, Aniagwu T, Nkwodimmah C, Akang EE (2007) Immunohistochemical and molecular subtypes of breast cancer in Nigeria. Breast Cancer Res Treat; doi:10.1007/s10549-007-9694-5
    1. Adebamowo CA, Ogundiran TO, Adenipekun AA, Oyesegun RA, Campbell OB, Akang EE, Rotimi CN, Olopade OI (2003a) Waist-hip ratio and breast cancer risk in urbanized Nigerian women. Breast Cancer Res 5: R18–R24
    1. Adebamowo CA, Ogundiran TO, Adenipekun AA, Oyesegun RA, Campbell OB, Akang EU, Rotimi CN, Olopade OI (2003b) Obesity and height in urban Nigerian women with breast cancer. Ann Epidemiol 13: 455–461
    1. Chu KC, Anderson WF (2002) Rates for breast cancer characteristics by estrogen and progesterone receptor status in the major racial/ethnic groups. Breast Cancer Res Treat 74: 199–211
    1. Clavel-Chapelon F, Gerber M (2002) Reproductive factors and breast cancer risk. Do they differ according to age at diagnosis? Breast Cancer Res Treat 72: 107–115
    1. Colditz GA, Baer HJ, Tamimi RM (2006) Breast Cancer. In Cancer Epidemiology and Prevention, Schottenfeld D, Fraumeni JF (eds), pp 995–1012. New York: Oxford University Press
    1. 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: 187–195
    1. Greenland S (1998) Introduction to regression models. In Modern Epidemiology, Rothman KJ, Greenland S (eds), pp 359–399. Philadelphia: Lippincott Willams & Wilkins
    1. Gukas ID, Jennings BA, Mandong BM, Igun GO, Girling AC, Manasseh AN, Ugwu BT, Leinster SJ (2005) Clinicopathological features and molecular markers of breast cancer in Jos, Nigeria. West Afr J Med 24: 209–213
    1. Hsieh CC, Trichopoulos D, Katsouyanni K, Yuasa S (1990) Age at menarche, age at menopause, height and obesity as risk factors for breast cancer: associations and interactions in an international case–control study. Int J Cancer 46: 796–800
    1. Huo D, Kim H-J, Adebamowo CA, Ogundiran TO, Akang EE, Campbell O, Adenipekun A, Niu Q, Sveen L, Fackenthal JD, Fackenthal DL, Das S, Cox N, Rienzo AD, Olopade OI (2007) Genetic polymorphisms in uridine diphospho-glucuronosyltransferase 1A1 and breast cancer risk in Africans. Breast Cancer Res Treat; doi:10.1007/s10549-007-9720-7
    1. Ikpatt OF, Ndoma-Egba R (2003) Oestrogen and progesterone receptors in Nigerian breast cancer: relationship to tumour histopathology and survival of patients. Cent Afr J Med 49: 122–126
    1. Kelsey JL, Gammon MD, John EM (1993) Reproductive factors and breast cancer. Epidemiol Rev 15: 36–47
    1. Lambe M, Hsieh C, Trichopoulos D, Ekbom A, Pavia M, Adami HO (1994) Transient increase in the risk of breast cancer after giving birth. N Engl J Med 331: 5–9
    1. Ma H, Bernstein L, Pike MC, Ursin G (2006) Reproductive factors and breast cancer risk according to joint estrogen and progesterone receptor status: a meta-analysis of epidemiological studies. Breast Cancer Res 8: R43.
    1. Okobia M, Bunker C, Zmuda J, Kammerer C, Vogel V, Uche E, Anyanwu S, Ezeome E, Ferrell R, Kuller L (2006) Case–control study of risk factors for breast cancer in Nigerian women. Int J Cancer 119: 2179–2185
    1. Parkin DM, Whelan SL, Ferlay J, Storm H (2005) Cancer Incidence in Five Continents. Vol. I to VIII. Lyon: IARC CancerBase No. 7
    1. Rosner B, Colditz GA, Willett WC (1994) Reproductive risk factors in a prospective study of breast cancer: the Nurses' Health Study. Am J Epidemiol 139: 819–835
    1. Royston P (2004) Multiple imputation of missing values. Stata Journal 4: 227–241
    1. Rubin DB (1987) Multiple Imputation for Nonresponse in Surveys. New York: John Wiley
    1. van Buuren S, Boshuizen HC, Knook DL (1999) Multiple imputation of missing blood pressure covariates in survival analysis. Stat Med 18: 681–694

Source: PubMed

Спонсоры и соавторы

Заболевания

Медикаментозные вмешательства

Подписаться