In summary, we have shown in one of the largest international studies to date that later age at menarche and increased adult height are both positively associated with measures of MD. The associations observed for height are in line with previous findings for associations with breast cancer risk, but those for menarche are in the opposite direction. These findings suggest that the association of age at menarche with breast cancer risk is not likely mediated through MD. Whether the well-established positive association of height with breast cancer risk is driven in whole or in part by elevated MD warrants further study. These results suggest a complex relationship between growth and development, MD and breast cancer risk.
BMI: Body mass index; DA: Dense area; ICMD: International Consortium of Mammographic Density; IGF: Insulin-like growth factor; IGF-1: Insulin-like growth factor-1; MD: Mammographic density; PD: Percent density.
The Melbourne Collaborative Cohort Study acknowledges that their cases and their vital status were ascertained through the Victorian Cancer Registry (VCR) and the Australian Institute of Health and Welfare (AIHW), including the National Death Index and the Australian Cancer Database. Isfahan University acknowledges assistance from Dr. Vida Razavi and Dr. Shamila Razavi. Instituto Nacional de Salud Publica acknowledges the Ministry of Education of Mexico and the Institute for Social Security and Services for State Workers' Medical Directorate staff and regional office in Jalisco for technical and administrative support. Where authors are identified as personnel of the International Agency for Research on Cancer/World Health Organization, the authors alone are responsible for the views expressed in this article and they do not necessarily represent the decisions, policy or views of these organizations.
This work was supported by the US National Cancer Institute at the National Institutes of Health [R03CA167771]; the International Agency for Research on Cancer; the University of Western Australia [Research Collaboration Award] and the Cancer Council Western Australia [Capacity Building and Collaboration Grant]. Original studies were supported, according to country by: Australia VicHealth; Cancer Council Victoria; Australian National Health and Medical Research Council [209057, 251,553 and 504711]; Australian National Breast Cancer Foundation [to JSt]; Canada the National Cancer Institute of Canada [to NFB]; Chile Fondecyt [11100238 to MLG, 1120326, 1130277, 3130532]; World Cancer Research Fund [2010/245]; Ellison Medical Foundation Grant [to AP]; Iran Isfahan University of Medical Sciences; Israel The Israel Cancer Association; Republic of Korea Asan Medical Center [2010-0811]; Malaysia Sime Darby LPGA Tournament; Ministry of Education University Malaya [High Impact Research Grant UM.C/HIR/MOHE/06]; University Malaya [Research Grant UMRG RP046B-15HTM]; Mexico National Council of Science and Technology (Mexico); the American Institute for Cancer Research [10A035]; Netherlands EPIC-NL-Europe against Cancer Programme of the European Commission (SANCO); Dutch Ministry of Health; Dutch Cancer Society; ZonMW the Netherlands Organisation for Health Research and Development; World Cancer Research Fund (WCRF); Poland Polish-Norwegian Research Programme [PNRF-243-AI-1/07]; Singapore National Medical Research Council [Clinician Scientist Award]; National University Cancer Institute Singapore (NCIS) Centre grant programme from National Medical Research Council; South Africa Pink Drive; Spain Spain's Health Research Fund (Fondo de Investigacion Santiaria) [PI060386 and PS09/0790]; Spanish Federation of Breast Cancer Patients (FECMA) [EPY1169-10]; Turkey-Roche Mustahzarlari San. A.S., Istanbul, Turkey; UK UK Engineering and Physical Sciences Research Council [EP/K020439/1 to JHi]; Breast Cancer Campaign [2007MayPR23], Cancer Research UK [G186/11 and C405/A14565]; Da Costa Foundation UK; USA National Cancer Institute [R01CA85265, R37 CA54281, R01 CA97396, P50 CA116201, R01 CA177150 and R01 CA140286]; Cancer Center Support Grant [CA15083; CA131332, CA124865, UM1 CA186107 and UM1 CA176726]; the Susan G. Komen Foundation.
Availability of data and materials
ICMD data cannot be deposited publicly as these data originate from 27 research institutions across 22 countries with different legal and ethical frameworks. Researchers seeking the analysis data set for this work are able to apply to the Environment and Lifestyle Epidemiology Branch at the International Agency for Research on Cancer for access (email: firstname.lastname@example.org).
Ethics approval and consent to participate
Ethics approvals for ICMD were obtained from the International Agency for Research on Cancer (IEC 12 ± 34). Each individual study obtained informed consent to participate from women included in the study and had received local ethical approval at the time of the original conduct of the study and again to contribute to the consortium.
Consent for publication
Breast Cancer Res. 2022;24(49) © 2022 BioMed Central, Ltd.
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