Birth characteristics and subsequent risk for breast cancer in very young women.
There is growing evidence that prenatal exposures may influence later breast cancer risk. This matched case-control study used linked New York State birth and tumor registry data to examine the association between birth characteristics and breast cancer risk among women aged 14-37 years. Cases were women diagnosed with breast cancer between 1978 and 1995 who were also born in New York after 1957 (n = 484). For each case, selected controls were the next six liveborn females with the same maternal county of residence. The authors found a J-shaped association between birth weight and breast cancer risk, and very high birth weight (> or =4,500 g) was associated with the greatest elevation in risk (adjusted odds ratio (OR) = 3.10, 95% confidence interval (CI): 1.18, 7.97). The association of maternal age with breast cancer risk was also J-shaped, with maternal age of more than 24 years showing a positive, linear association (adjusted OR = 1.94, 95% CI: 1.18, 3.18 for maternal age > or =35 vs. 20-24 years; p for trend = 0.02). In contrast, women born very preterm had a lower risk (adjusted OR = 0.11, 95% CI: 0.02, 0.79 for gestational age <33 vs. > or =37 weeks). These findings support a role for early life factors in the development of breast cancer in very young women.
Innes
K
K
Department of Preventive Medicine and Biometrics, University of Colorado Health Sciences Center, Denver 80262, USA. Kim.Innes@UCHSC.edu
Byers
T
T
Schymura
M
M
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D005320:Fetal Macrosomia / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008423:Maternal Age; D009518:New York / Q000453:epidemiology; D016017:Odds Ratio; D011159:Population Surveillance; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D012016:Reference Values; D012042:Registries; D012307:Risk Factors