American Journal of Epidemiology Vol. 126, No. 5: 831-841
Copyright © 1987 by The Johns Hopkins University School of Hygiene and Public Health
research-article |
A PROSPECTIVE STUDY OF REPRODUCTIVE FACTORS AND BREAST CANCER
I. PARITY
1Institute of Hygiene and Social Medicine, University of Bergen Cancer Registry of Norway, Oslo, Norway
2Department of Mathematics, University of Bergen Norway
3Section for Medical Informatics and Statistics, University of Bergen Norway
Reprint requests to Dr. Gunnar KvÂle, Institute of Hygiene and Social Medicine, N-5016 Haukeland Sykehus, Norway
The relation between childbearing and breast cancer risk was investigated in a prospective study of 63,090 Norwegian women, among whom 1,565 breast cancer cases occurred in a follow-up from 1961 through 1980. The authors observed a strong and highly significant inverse association between the number of full-term pregnancies and the risk of breast cancer. The association was consistently found in all subgroups according to demographic variables and was obtained for all histologic subtypes except for cases classified as Paget's disease. The relation with parity could not be explained by confounding with age at first birth or other reproductive factors. The apparent protective effect of high parity was strongest in the groups with an early first birth, and no such effect could be established among women with their first birth at age 35 or later. The protective effect of muttiparity was observed for cancers in all age groups. Uniparous women had, however, higher risk of developing breast cancer under age 60 than nulliparous women. Those who reported at least one abortion had somewhat lower risk than those who did not, but no trend according to the number of abortions was observed.
abortion; breast neoplasms; parity; prospective studies
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
C. Sweeney, C. K. Blair, K. E. Anderson, D. Lazovich, and A. R. Folsom Risk Factors for Breast Cancer in Elderly Women Am. J. Epidemiol., November 1, 2004; 160(9): 868 - 875. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Mahue-Giangreco, G. Ursin, J. Sullivan-Halley, and L. Bernstein Induced Abortion, Miscarriage, and Breast Cancer Risk of Young Women Cancer Epidemiol. Biomarkers Prev., March 1, 2003; 12(3): 209 - 214. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. M. D'Cruz, S. E. Moody, S. R. Master, J. L. Hartman, E. A. Keiper, M. B. Imielinski, J. D. Cox, J. Y. Wang, S. I. Ha, B. A. Keister, et al. Persistent Parity-Induced Changes in Growth Factors, TGF-{beta}3, and Differentiation in the Rodent Mammary Gland Mol. Endocrinol., September 1, 2002; 16(9): 2034 - 2051. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. Thompson, P-L. Chen, R. A. King, S. S. Rich, W. S. Oetting, C. Armstrong, A. R. Folsom, and T. A. Sellers BRCA1 Susceptibility Markers and Postmenopausal Breast Cancer: The Iowa Women's Health Study Cancer Epidemiol. Biomarkers Prev., May 1, 2000; 9(5): 507 - 511. [Abstract] [Full Text] |
||||
![]() |
Bibliography Current Sociology, January 1, 1998; 46(1): 128 - 144. |
||||
![]() |
M. Melbye, J. Wohlfahrt, J. H. Olsen, M. Frisch, T. Westergaard, K. Helweg-Larsen, and P. K. Andersen Induced Abortion and the Risk of Breast Cancer N. Engl. J. Med., January 9, 1997; 336(2): 81 - 85. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. A. Newcomb, B. E. Storer, M. P. Longnecker, R. Mittendorf, E. R. Greenberg, and W. C. Willett Pregnancy Termination in Relation to Risk of Breast Cancer JAMA, January 24, 1996; 275(4): 283 - 287. [Abstract] [PDF] |
||||
![]() |
M. Lambe, C.-c. Hsieh, D. Trichopoulos, A. Ekbom, M. Pavia, and H.-O. Adami Transient Increase in the Risk of Breast Cancer after Giving Birth N. Engl. J. Med., July 7, 1994; 331(1): 5 - 9. [Abstract] [Full Text] |
||||
![]() |
T. Colton, E. R. Greenberg, K. Noller, L. Resseguie, C. Van Bennekom, T. Heeren, and Y. Zhang Breast Cancer in Mothers Prescribed Diethylstilbestrol in Pregnancy: Further Follow-up JAMA, April 28, 1993; 269(16): 2096 - 2100. [Abstract] [PDF] |
||||





