Breast feeding practices in relation to endometrial cancer risk, USA
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Objective: Breast feeding is associated with reduced estrogen, a profile that should be associated with decreased endometrial cancer incidence. We analyzed data from a population-based case–control study of Wisconsin women to evaluate the relation between lactation and endometrial cancer risk.
Methods: Cases (n = 586) were identified from a statewide tumor registry; controls (n = 1653) were selected randomly from driver's license lists and Medicare beneficiary files. Breast feeding practices and other factors were ascertained by telephone interview.
Results: Compared with parous women who did not breast feed, the multivariate relative risk for women who breast fed for at least 2 weeks was 0.90 [95% confidence interval (CI) 0.72–1.13]; increasing duration was not strongly associated with risk of disease (p for trend 0.4). More recent breast feeding was associated with significantly reduced risks. The relative risk for lactation within the recent three decades was 0.58 (95% CI 0.36–0.96) and for first breast feeding at age 30 or greater was 0.50 (95% CI 0.28–0.90). There was a suggestion that risk was increased in women who used lactation suppressant hormones – usually estrogens – more recently (p = 0.1) or at a later age (p = 0.1).
Conclusions: This study suggests that, like breast cancer, endometrial cancer is modestly inversely associated with lactation.
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- 1.Baird DT, McNeilly AS, Sawers RS, Sharpe RM (1979) Failure of estrogen-induced discharge of luteinizing hormone in lactating women. J Clin Endocrinol Metab 49: 500–506.Google Scholar
- 2.Petrakis NL, Wrensch MR, Ernster VL, et al. (1987) Influence of pregnancy and lactation on serum and breast fluid estrogen levels: implications for breast cancer risk. Int J Cancer 40: 587–591.Google Scholar
- 3.Henderson BE, Ross RK, Judd HL, Krailo MD, Pike MC (1985) Do regulatory ovulatory cycles increase breast cancer risk? Cancer 56: 1206–1208.Google Scholar
- 4.Key TJ, Pike MC (1988) The dose-effect relationship between “unopposed” oestrogens and endometrial mitotic rate: its central role in explaining and predicting endometrial cancer risk. Br J Cancer 57: 205–212.Google Scholar
- 5.Kelsey JL, LiVolsi VA, Holford TR, et al. (1982) A case-control study of cancer of the endometrium. Am J Epidemiol 116: 333–342.Google Scholar
- 6.Brinton LA, Berman ML, Mortel R, et al. (1992) Reproductive, menstrual, and medical risk factors for endometrial cancer: results from a case-control study. Am J Obstet Gynecol 167: 1317–1325.Google Scholar
- 7.Rosenblatt KA, Thomas DB (1995) Prolonged lactation and endometrial cancer. WHO Collaborative Study of Neoplasia and Steroid Contraceptives. Int J Epidemiol 24: 499–503.Google Scholar
- 8.Salazar-Martinez E, Lascano-Ponce C, Lira-Lira GG, et al. (1999) Reproductive factors of ovarian and endometrial cancer risk in a high fertility population in Mexico. Cancer Res 59: 3658–3662.Google Scholar
- 9.Breslow NE, Day N (1980) Statistical Methods in Cancer Research, Vol. 1: The Analysis of Case–control Studies. Lyon: International Agency for Research on Cancer (IARC Scientific Publication, No. 32).Google Scholar
- 10.Howie PW, McNeilly AS, Houston MJ, et al. (1981) Effect of supplementary foods on suckling patterns and ovarian activity during lactation. Br Med J (Clin Res Ed) 283: 757–759.Google Scholar
- 11.London SJ (1994) Breast feeding and breast cancer (Letter). N Engl J Med 330: 1682.Google Scholar
- 12.Grady D, Gebretsadik T, Kerlikowske K, Ernster V, Pettiti D (1995) Hormone replacement therapy and endometrial cancer risk: a meta analysis. Obstet Gynecol 85: 304–313.Google Scholar
- 13.Newcomb PA (1997) Lactation and breast cancer risk. J Mammary Gland Biol Neoplasia 2: 311–318.Google Scholar
- 14.Siiteri PK (1978) Steroid hormones and endometrial cancer. Cancer Res 38: 4360–4366.Google Scholar
- 15.Ries LAG, Kosary Cl, Hankey BF, Miller BA, Harris A, Edwards BK, eds. SEER Cancer Statistics Review, 1973–1994. National Cancer Institute. NIH Publication. No. 97–2789. Bethesda, MD.Google Scholar