Here are some on breast cancer and breastfeeding.  The last one shows 
some protection for the *infant*.

Jack Newman, MD, FRCPC

Layde PM, Webster LA, Baughman AL, Wingo PA, Rubin GL, Ory HW and the 
cancer and steroid hormone study group. 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;42:963-73

Ing R, Ho JHC, Petrakis NL. Unilateral breastfeeding and breast 
cancer. Lancet July 16, 19977;124-27

McTiernan A, Thomas DB. Evidence for a protective effect of lactation 
on risk of breast cancer in young women. Am J Epidemiol 
1986;124:353-74

Yuan J-M, Yu MC, Ross RK, Gao Y-T, Henderson BE. Risk factors for 
breast cancer in Chinese women in Shanghai. Cancer Res 1988;58:99-104

Yoo K-Y, Tajima K, Kuroishi T, Hirose K, Yoshida M, Miura S, Murai H. 
Independent protective effect of lactation against breast cancer: a 
case-control study in Japan. Am J Epidemiol 1992;135:726-33

Reuter KL, Baker SP, Krolikowski FJ. Risk factors for breast cancer in 
women undergoing mammography. Am J Radiol 1992;158:273-8

United Kingdom National Case-Control Study Group. Breastfeeding and 
risk of breast cancer in young women. Br Med J 1993;307:17-20

Newcomb PA, Storer BE, Longnecker MP, Mittendorf R, Greenberg ER, 
Clapp RW, et al. Lactation and a reduced risk of premenopausal breast 
cancer. N Eng J Med 1994;330:81-7

Tao S-C, Yu MC, Ross RK, Xiu K-W. Risk factors for breast cancer in 
Chinese women of Beijing. Int J Cancer 1988;42:495-98

Siskind V, Schofield F, Rice D, Bain C. Breast cancer and 
breastfeeding: results from an Australian case-control study. Am J 
Epidemiol 1989;130:229-36

Romieu I, Hernández-Avila M, Lazcano E, Lopez L, Romero-Jaime R. 
Breast cancer and lactation history in Mexican women. Am J Epidemiol 
1996;143:543-52

Freudenheim JL, Marshall JR, Graham S, Laughlin R, Vena JE, Bandera E, 
et al. Exposure to breastmilk in infancy and the risk of breast 
cancer. Epidemiology 1994;5:324-31