Breast cancer in relation to the occurrence and time of induced and spontaneous abortion Journal Article


Authors: Rosenberg, L.; Palmer, J. R.; Kaufman, D. W.; Strom, B. L.; Schottenfeld, D.; Shapiro, S.
Article Title: Breast cancer in relation to the occurrence and time of induced and spontaneous abortion
Abstract: The authors evaluated whether an induced or spontaneous abortion during the first six months of gestation, particularly if it occurs before the first term pregnancy, increases the risk of breast cancer. Data from a case-control study of women under 70 years of age were used: 3,200 cases of breast cancer were compared with 4,844 controls with nonmalignant nongynecologic conditions. Among both nulliparous and parous women, the risk of breast cancer was not related to the number of induced or spontaneous abortions. After allowance for all identified potential confounding factors, the estimated relative risk for nulliparous women with an induced abortion relative to those who had never been pregnant was 1.3 (95% confidence interval (Cl) 0.8-2.2), and for spontaneous abortion, the corresponding estimate was 0.9 (95% Cl 0.5-1.5). Among parous women, the estimated relative risks were 1.2 (95% Cl 0.9-1.6) for an induced abortion and 0.9 (95% Cl 0.8-1.0) for a spontaneous abortion, relative to never having had an abortion of any type. The time of the abortion had little effect: The relative risk estimates were 0.9 (95% Cl 0.5-1.4) for induced abortion before the first term birth, 1.4 (95% Cl 1.0-1.9) for induced abortion first occurring after the first term birth, 0.9 (95% Cl 0.7-1.2) for spontaneous abortion before the first term birth, and 0.9 (95% Cl 0.7-1.0) for spontaneous abortion first occurring after the first term birth. Similar results were evident for women under age 40, among whom the frequency of induced abortion was relatively high. These data suggest that the risk of breast cancer is not materially affected by abortion, regardless of whether it occurs before or after the first term birth. © 1988 by The Johns Hopkins University School of Hygiene and Public Health.
Keywords: adult; controlled study; major clinical study; case control study; united states; neoplasms; breast cancer; biology; risk factors; age factors; breast neoplasms; time factors; population; pregnancy; developing countries; new york; fertility; population dynamics; diseases; north america; massachusetts; reproduction; pregnancy complications; medical records; family planning; pennsylvania; spontaneous abortion; parity; maryland; abortion; developed countries; americas; primigravida; demographic factors; cancer; human; female; priority journal; nulliparity; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; fertility measurements; northern america; abortion, induced; abortion, spontaneous; statistical regression; fertility control, postconception; induced abortion; multiparity; pregnancy, first trimester
Journal Title: American Journal of Epidemiology
Volume: 127
Issue: 5
ISSN: 0002-9262
Publisher: Oxford University Press  
Date Published: 1988-05-01
Start Page: 981
End Page: 989
Language: English
DOI: 10.1093/oxfordjournals.aje.a114901
PUBMED: 2578017
PROVIDER: scopus
DOI/URL:
Notes: Article -- Export Date: 6 August 2020 -- Source: Scopus
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