Abstract
Exposure to ionizing radiation is a known risk factor for breast cancer and the fertility pattern is a recognized modifier of breast cancer risk. The aim of this study was to elucidate the interaction between these 2 factors. This study is based on a Swedish cohort of 17 202 women who had been irradiated for skin haemangiomas in infancy between 1920 and 1965. The mean age at treatment was 6 months and the median breast dose was 0.05 Gy (range 0–35.8 Gy). Follow-up information on vital status, parity, age at first childbirth and breast cancer incidence was retrieved through record linkage with national population registers for the period 1958–1995. Analyses of excess relative risk (ERR) models were performed using Poisson regression methods. In this cohort, the fertility pattern differed from that in the Swedish population, with significantly fewer childbirths overall and before 25 years of age but more childbirth after that age. There were 307 breast cancers in the cohort and the standardized incidence ratio (SIR) was 1.22 (95% CI 1.09–1.36). A linear dose–response model with stratification for fertility pattern and menopausal status resulted in the best fit of the data. ERR/Gy was 0.33 (95% CI 0.17–0.53). In absolute terms this means an excess of 2.1 and 5.4 cases per Gy per 104breast-years in the age groups 40–49 and 50–59 years respectively. The fertility pattern influenced the breast cancer risk in this irradiated population in a similar way to that observed in other studies. SIR at dose = 0 was highest, 2.31, among postmenopausal nulliparous women (95% CI 1.48–3.40, n = 62). SIR at dose = 0 was lowest in pre- or postmenopausal women with a first childbirth before 25 years of age; 0.89 (0.71–1.09) and 0.88 (0.58–1.25) respectively. Thus, in addition to the dose–effect response in the cohort, part of the breast cancer excess could be explained by a different fertility pattern. The estimates of ERR/Gy for the various categories of age at first childbirth, number of children, menopausal status and ovarian dose were very similar, contradicting any interaction effects on the scale of relative risk. © 2001 Cancer Research Campaign
Similar content being viewed by others
Article PDF
Change history
16 November 2011
This paper was modified 12 months after initial publication to switch to Creative Commons licence terms, as noted at publication
References
Baral E, Larsson LE and Mattsson B (1977) Breast cancer following irradiation of the breast. Cancer 40: 2905–2910
Beir V (1990). Health effects of exposure to low levels of ionizing radiation, National Research Council, National Academy Press
Boice JD, Monson RR and Rosenstein M (1981) Cancer mortality in women after repeated fluoroscopic examinations of the chest. J Natl Cancer Inst 66: 863–867
Boice JD Jr, Preston D, Davis FG and Monson RR (1991) Frequent chest X-ray fluoroscopy and breast cancer incidence among tuberculosis patients in Massachusetts. Radiat Res 125: 214–222
Davis FG, Boice JD Jr, Hrubec Z and Monson RR (1989) Cancer mortality in a radiation-exposed cohort of Massachusetts tuberculosis patients. Cancer Res 49: 6130–6136
Goodman MT, Cologne JB, Moriwaki H, Vaeth M and Mabuchi K (1997) Risk factors for primary breast cancer in Japan: 8-year follow-up of atomic bomb survivors. Prev Med 26: 144–153
Hoffman DA, Lonstein JE, Morin MM, Visscher W, Harris BSd and Boice JD Jr (1989) Breast cancer in women with scoliosis exposed to multiple diagnostic x rays. J Natl Cancer Inst 81: 1307–1312
Howe GR and McLaughlin J (1996) Breast cancer mortality between 1950 and 1987 after exposure to fractionated moderate-dose-rate ionizing radiation in the Canadian fluoroscopy cohort study and a comparison with breast cancer mortality in the atomic bomb survivors study. Radiat Res 145: 694–707
Hrubec Z, Boice JD Jr, Monson RR and Rosenstein M (1989) Breast cancer after multiple chest fluoroscopies: second follow-up of Massachusetts women with tuberculosis. Cancer Res 49: 229–234
Kallen B, Karlsson P, Lundell M, Wallgren A and Holm LE (1998) Outcome of reproduction in women irradiated for skin hemangioma in infancy. Radiat Res 149: 202–208
Land CE, Hayakawa N, Machado SG, Yamada Y, Pike MC, Akiba S and Tokunaga M (1994) A case-control interview study of breast cancer among Japanese A-bomb survivors II Interactions with radiation dose. Cancer Causes Control 5: 167–176
Lundell M (1994) Estimates of absorbed dose in different organs in children treated with radium for skin hemangiomas. Radiat Res 140: 327–333
Lundell M, Mattsson A, Karlsson P, Holmberg E, Gustafsson A and Holm LE (1999) Breast cancer risk after radiotherapy in infancy: a pooled analysis of two Swedish cohorts of 17,202 infants. Radiat Res 151: 626–632
MacMahon B, Cole P, Lin TM, Lowe CR, Mirra AP, Ravnihar B, Salber EJ, Valaoras VG and Yuasa S (1970) Age at first birth and breast cancer risk. Bull World Health Organ 43: 209–221
Modan B, Chetrit A, Alfandary E and Katz L (1989) Increased risk of breast cancer after low-dose irradiation [published erratum appears in Lancet 1989 Apr 22; 1 (8643): 916]. Lancet 1: 629–631
Preston D, Lubin JH, Pierce DA and McConney ME (1988–1993). EPICURE User's Guide, Hirsoft International Corp: Seattle
Shore RE, Hildreth N, Woodard E, Dvoretsky P, Hempelmann L and Pasternack B (1986) Breast cancer among women given X-ray therapy for acute postpartum mastitis. J Natl Cancer Inst 77: 689–696
Tokunaga M, Land CE and Tokuoka S (1991) Follow-up studies of breast cancer incidence among atomic bomb survivors. J Radiat Res (Tokyo) 32 (Suppl): 201–211
Tokunaga M, Land CE, Tokuoka S, Nishimori I, Soda M and Akiba S (1994) Incidence of female breast cancer among atomic bomb survivors, 1950–1985. Radiat Res 138: 209–223
Author information
Authors and Affiliations
Rights and permissions
From twelve months after its original publication, this work is licensed under the Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/
About this article
Cite this article
Holmberg, E., Holm, LE., Lundell, M. et al. Excess breast cancer risk and the role of parity, age at first childbirth and exposure to radiation in infancy. Br J Cancer 85, 362–366 (2001). https://doi.org/10.1054/bjoc.2001.1868
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1054/bjoc.2001.1868
Keywords
This article is cited by
-
Individual response of humans to ionising radiation: governing factors and importance for radiological protection
Radiation and Environmental Biophysics (2020)
-
Association between the XRCC3 polymorphisms and breast cancer risk: meta-analysis based on case–control studies
Molecular Biology Reports (2012)
-
Genetic polymorphism of XRCC3 Thr241Met and breast cancer risk: case-control study in Korean women and meta-analysis of 12 studies
Breast Cancer Research and Treatment (2007)
-
The impact of reproductive factors on breast cancer risk - The feasibility of using Swedish population-based registers to account for the effect of confounding in cohort studies
Cancer Causes & Control (2005)
-
Radiation and breast cancer: a review of current evidence
Breast Cancer Research (2004)