Search tips
Search criteria 


Logo of bmjThe BMJ
BMJ. 1989 December 9; 299(6713): 1430–1432.
PMCID: PMC1838310

Risk of cancer of the breast after legal abortion during first trimester: a Swedish register study.


An increase in induced abortions in Sweden has been accompanied by an increase in the incidence of breast cancer of about 40% in women aged 20-44. To assess whether the apparent risk is real the risk of breast cancer was investigated in practically all Swedish women with a history of a legal abortion in the first trimester before the age of 30 during 1966-74 (n = 49,000). The cohort was followed up in the Swedish cancer register to identify cases of breast cancer diagnosed more than five years after the abortion until the end of 1984. The number of observed cases of breast cancer was 65 compared with an expected number of 84.5, estimated from the contemporary Swedish population with due consideration to age, giving a relative risk of 0.8 (95% confidence interval 0.58 to 0.99). Contrary to most earlier reports, this study did not indicate any overall increased risk of breast cancer after an induced abortion in the first trimester in young women.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (695K), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Salber EJ, Trichopulos D, MacMahon B. Lactation and reproductive histories of breast cancer patients in Boston, 1965-66. J Natl Cancer Inst. 1969 Nov;43(5):1013–1024. [PubMed]
  • Valaoras VG, MacMahon B, Trichopoulos D, Polychronopoulou A. Lactation and reproductive histories of breast cancer patients in greater Athens, 1965-67. Int J Cancer. 1969 May 15;4(3):350–363. [PubMed]
  • Lin TM, Chen KP, MacMahon B. Epidemiologic characteristics of cancer of the breast in Taiwan. Cancer. 1971 Jun;27(6):1497–1504. [PubMed]
  • Lowe CR, MacMahon B. Breast cancer and reproductive history of women in South Wales. Lancet. 1970 Jan 24;1(7639):153–156. [PubMed]
  • Yuasa S, MacMahon B. Lactation and reproductive histories of breast cancer patients in Tokyo, Japan. Bull World Health Organ. 1970;42(2):195–204. [PubMed]
  • Ravnihar B, MacMahon B, Lindtner J. Epidemiologic features of breast cancer in Slovenia, 1965-1967. Eur J Cancer. 1971 Aug;7(4):295–306. [PubMed]
  • Stavraky K, Emmons S. Breast cancer in premenopausal and postmenopausal women. J Natl Cancer Inst. 1974 Sep;53(3):647–654. [PubMed]
  • Soini I. Risk factors of breast cancer in Finland. Int J Epidemiol. 1977 Dec;6(4):365–373. [PubMed]
  • Choi NW, Howe GR, Miller AB, Matthews V, Morgan RW, Munan L, Burch JD, Feather J, Jain M, Kelly A. An epidemiologic study of breast cancer. Am J Epidemiol. 1978 Jun;107(6):510–521. [PubMed]
  • Paffenbarger RS, Jr, Greenberg LM, Chang HG, Kampert JB. Epidemiologic characteristics of breast cancer in three menopausal stages: preliminary findings. Natl Cancer Inst Monogr. 1979 Nov;(53):195–202. [PubMed]
  • Paffenbarger RS, Jr, Kampert JB, Chang HG. Characteristics that predict risk of breast cancer before and after the menopause. Am J Epidemiol. 1980 Aug;112(2):258–268. [PubMed]
  • Toti A, Piffanelli A, Pavanelli T, Buriani C, Nenci I, Arslan-Pagnini C, Zanardi P, Pecorari S, Rossi R, Barrai I. Possible indication of breast cancer risk through discriminant functions. Cancer. 1980 Sep 1;46(5):1280–1285. [PubMed]
  • Pike MC, Henderson BE, Casagrande JT, Rosario I, Gray GE. Oral contraceptive use and early abortion as risk factors for breast cancer in young women. Br J Cancer. 1981 Jan;43(1):72–76. [PMC free article] [PubMed]
  • Brinton LA, Hoover R, Fraumeni JF., Jr Reproductive factors in the aetiology of breast cancer. Br J Cancer. 1983 Jun;47(6):757–762. [PMC free article] [PubMed]
  • Helmrich SP, Shapiro S, Rosenberg L, Kaufman DW, Slone D, Bain C, Miettinen OS, Stolley PD, Rosenshein NB, Knapp RC, et al. Risk factors for breast cancer. Am J Epidemiol. 1983 Jan;117(1):35–45. [PubMed]
  • Hirohata T, Shigematsu T, Nomura AM, Nomura Y, Horie A, Hirohata I. Occurrence of breast cancer in relation to diet and reproductive history: a case-control study in Fukuoka, Japan. Natl Cancer Inst Monogr. 1985 Dec;69:187–190. [PubMed]
  • La Vecchia C, Decarli A, Parazzini F, Gentile A, Negri E, Cecchetti G, Franceschi S. General epidemiology of breast cancer in northern Italy. Int J Epidemiol. 1987 Sep;16(3):347–355. [PubMed]
  • Ewertz M, Duffy SW. Risk of breast cancer in relation to reproductive factors in Denmark. Br J Cancer. 1988 Jul;58(1):99–104. [PMC free article] [PubMed]
  • Rosenberg L, Palmer JR, Kaufman DW, Strom BL, Schottenfeld D, Shapiro S. Breast cancer in relation to the occurrence and time of induced and spontaneous abortion. Am J Epidemiol. 1988 May;127(5):981–989. [PubMed]
  • Howe HL, Senie RT, Bzduch H, Herzfeld P. Early abortion and breast cancer risk among women under age 40. Int J Epidemiol. 1989 Jun;18(2):300–304. [PubMed]
  • Russo J, Tay LK, Russo IH. Differentiation of the mammary gland and susceptibility to carcinogenesis. Breast Cancer Res Treat. 1982;2(1):5–73. [PubMed]
  • Little JB, Hahn GM. Life-cycle dependence of repair of potentially-lethal radiation damage. Int J Radiat Biol Relat Stud Phys Chem Med. 1973 Apr;23(4):401–407. [PubMed]
  • Petrakis NL. Cerumen genetics and human breast cancer. Science. 1971 Jul 23;173(3994):347–349. [PubMed]
  • Russo J, Russo IH. DNA labeling index and structure of the rat mammary gland as determinants of its susceptibility to carcinogenesis. J Natl Cancer Inst. 1978 Dec;61(6):1451–1459. [PubMed]
  • Nagasawa H, Yanai R. Frequency of mammary cell division in relation to age: its significance in the induction of mammary tumors by carcinogen in rats. J Natl Cancer Inst. 1974 Feb;52(2):609–610. [PubMed]
  • Wacholder S, Boivin JF. External comparisons with the case-cohort design. Am J Epidemiol. 1987 Dec;126(6):1198–1209. [PubMed]
  • Mattsson B, Wallgren A. Completeness of the Swedish Cancer Register. Non-notified cancer cases recorded on death certificates in 1978. Acta Radiol Oncol. 1984;23(5):305–313. [PubMed]
  • MacMahon B, Cole P, Brown J. Etiology of human breast cancer: a review. J Natl Cancer Inst. 1973 Jan;50(1):21–42. [PubMed]
  • Lipnick R, Speizer FE, Bain C, Willett W, Rosner B, Stampfer MJ, Belanger C, Hennekens CH. A case-control study of risk indicators among women with premenopausal and early postmenopausal breast cancer. Cancer. 1984 Feb 15;53(4):1020–1024. [PubMed]
  • Kvåle G, Heuch I, Eide GE. A prospective study of reproductive factors and breast cancer. I. Parity. Am J Epidemiol. 1987 Nov;126(5):831–841. [PubMed]

Articles from The BMJ are provided here courtesy of BMJ Group