Skip to main content

The incidence of breast cancer in Canada 1971–2015: trends in screening-eligible and young-onset age groups

Abstract

Objectives

Breast cancer incidence has fluctuated considerably in Canada, with recent reductions in rates among screening-eligible women. However, incidence of early-onset and pre-menopausal breast cancer is understudied. We examined age-specific trends in breast cancer incidence between 1971 and 2015, as well as possible trends by birth cohort.

Methods

Incidence data were collected from the National Cancer Incidence Reporting System and the Canadian Cancer Registry, and annual percent changes were estimated using the Joinpoint Regression Program. Five-year birth cohort models were fit using the National Cancer Institute’s web tool.

Results

Breast cancer incidence among women under age 40 has increased since 2000, while incidence under 50 has remained stable. Rates of post-menopausal breast cancer declined sharply and have recently plateaued. More recent birth cohorts are at a non-significantly increased risk of breast cancer compared with the reference, with an increasing upward trend.

Conclusions

Rates of breast cancer may be increasing among younger women, and there is suggestive evidence that more recent birth cohorts are at increased risk of the disease. More research is needed into the risk factors for pre-menopausal breast cancer to support primary prevention efforts in this area.

Résumé

Objectifs

L’incidence du cancer du sein fluctue considérablement au Canada, avec des baisses récentes des taux chez les femmes admissibles au dépistage. Par contre, l’incidence du cancer du sein à début précoce et préménopausique est insuffisamment étudiée. Nous avons examiné les tendances selon l’âge de l’incidence du cancer du sein entre 1971 et 2015, ainsi que les éventuelles tendances par cohorte de naissance.

Méthode

Les données sur l’incidence proviennent du Système national de déclaration des cas de cancer et du Registre canadien du cancer, et les pourcentages de changement annuel ont été estimés à l’aide du programme de régression Joinpoint. Des modèles de cohorte de naissance de 5 ans ont été adaptés à l’aide d’un outil en ligne de l’Institut national du cancer.

Résultats

L’incidence du cancer du sein chez les femmes de moins de 40 ans augmente depuis 2000, tandis qu’elle est stable chez les femmes de moins de 50 ans. Après avoir diminué abruptement, les taux de cancer du sein postménopausique ont plafonné récemment. Les cohortes de naissance plus récentes présentent un risque accru non significatif de cancer du sein comparativement aux cohortes de référence, avec un mouvement de hausse.

Conclusions

Les taux de cancer du sein peuvent sembler croître chez les jeunes femmes, et les données portent à croire que les cohortes de naissance plus récentes présentent un risque accru pour cette maladie. Il faudrait pousser la recherche sur les facteurs de risque de cancer du sein préménopausique pour appuyer les démarches de prévention primaire dans ce domaine.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

References

  1. American Cancer Society. (2017). Breast cancer: facts & figures 2017-2018. Atlanta, GA: American Cancer Society Inc..

    Google Scholar 

  2. Anastasiadi, Z., Lianos, G. D., Ignatiadou, E., Harissis, H. V., & Mitsis, M. (2017). Breast cancer in young women: an overview. Updates in Surgery, 69(3), 313–317. https://doi.org/10.1007/s13304-017-0424-1.

    Article  PubMed  Google Scholar 

  3. Baeyens-Fernandez, J. A., Molina-Portillo, E., Pollan, M., Rodriguez-Barranco, M., Del Moral, R., Arribas-Mir, L., et al. (2018). Trends in incidence, mortality and survival in women with breast cancer from 1985 to 2012 in Granada, Spain: a population-based study. BMC Cancer, 18(1), 781. https://doi.org/10.1186/s12885-018-4682-1.

    Article  PubMed  PubMed Central  Google Scholar 

  4. Bleyer, A., & Welch, H. G. (2012). Effect of three decades of screening mammography on breast-cancer incidence. The New England Journal of Medicine, 367(21), 1998–2005. https://doi.org/10.1056/NEJMoa1206809.

    CAS  Article  PubMed  Google Scholar 

  5. Brenner, D. R., Poirier, A. E., Ruan, Y., Hebert, L. A., Grevers, X., Walter, S. D., et al. (2019). Estimates of the current and future burden of cancer attributable to excess body weight and abdominal adiposity in Canada. Preventive Medicine, 122, 49–64. https://doi.org/10.1016/j.ypmed.2019.03.014.

    Article  PubMed  Google Scholar 

  6. Brenner, D. R., Ruan, Y., Shaw, E., De, P., Heitman, S. J., & Hilsden, R. J. (2017). Increasing colorectal cancer incidence trends among younger adults in Canada. Preventive Medicine, 105, 345–349. https://doi.org/10.1016/j.ypmed.2017.10.007.

    Article  PubMed  Google Scholar 

  7. Canadian Cancer Statistics Advisory Committee (2017). Canadian Cancer statistics 2017. Toronto, ON: Canadian Cancer Society.

  8. Canadian Cancer Statistics Advisory Committee. (2018). Canadian cancer statistics 2018. Toronto, ON: Canadian Cancer Society.

    Google Scholar 

  9. Canadian Partnership Against Cancer. (2013). Organized breast cancer screening programs in Canada: report on program performance in 2007 and 2008. Toronto: Canadian Partnership Against Cancer.

    Google Scholar 

  10. Canadian Partnership Against Cancer. (2017). Breast cancer in Canada. Ottawa, ON: Public Health Agency of Canada.

    Google Scholar 

  11. Chen, G. C., Chen, S. J., Zhang, R., Hidayat, K., Qin, J. B., Zhang, Y. S., et al. (2016). Central obesity and risks of pre- and postmenopausal breast cancer: a dose-response meta-analysis of prospective studies. Obesity Reviews, 17(11), 1167–1177. https://doi.org/10.1111/obr.12443.

    Article  PubMed  Google Scholar 

  12. Costanian, C., McCague, H., & Tamim, H. (2018). Age at natural menopause and its associated factors in Canada: cross-sectional analyses from the Canadian Longitudinal Study on Aging. Menopause, 25(3), 265–272. https://doi.org/10.1097/GME.0000000000000990.

    Article  PubMed  Google Scholar 

  13. De, P., Neutel, C. I., Olivotto, I., & Morrison, H. (2010). Breast cancer incidence and hormone replacement therapy in Canada. Journal of the National Cancer Institute, 102(19), 1489–1495. https://doi.org/10.1093/jnci/djq345.

    CAS  Article  PubMed  Google Scholar 

  14. DeSantis, C. E., Bray, F., Ferlay, J., Lortet-Tieulent, J., Anderson, B. O., & Jemal, A. (2015). International variation in female breast cancer incidence and mortality rates. Cancer Epidemiology, Biomarkers & Prevention, 24(10), 1495–1506. https://doi.org/10.1158/1055-9965.EPI-15-0535.

    Article  Google Scholar 

  15. Harris, M. A., Prior, J. C., & Koehoorn, M. (2008). Age at menarche in the Canadian population: secular trends and relationship to adulthood BMI. The Journal of Adolescent Health, 43(6), 548–554. https://doi.org/10.1016/j.jadohealth.2008.07.017.

    Article  PubMed  Google Scholar 

  16. Klarenbach, S., Sims-Jones, N., Lewin, G., Singh, H., Theriault, G., Tonelli, M., et al. (2018). Recommendations on screening for breast cancer in women aged 40-74 years who are not at increased risk for breast cancer. CMAJ, 190(49), E1441–E1451. https://doi.org/10.1503/cmaj.180463.

    Article  PubMed  PubMed Central  Google Scholar 

  17. Kotsopoulos, J., Gronwald, J., Lynch, H. T., Eisen, A., Neuhausen, S. L., Tung, N., et al. (2018). Age at first full-term birth and breast cancer risk in BRCA1 and BRCA2 mutation carriers. Breast Cancer Research and Treatment, 171(2), 421–426. https://doi.org/10.1007/s10549-018-4822-y.

    CAS  Article  PubMed  Google Scholar 

  18. Labreche, F., Kim, J., Song, C., Pahwa, M., Ge, C. B., Arrandale, V. H., et al. (2019). The current burden of cancer attributable to occupational exposures in Canada. Preventive Medicine, 122, 128–139. https://doi.org/10.1016/j.ypmed.2019.03.016.

    Article  PubMed  Google Scholar 

  19. Miller, A. B., Wall, C., Baines, C. J., Sun, P., To, T, & Narod, S. A. (2014). Twenty five year follow-up for breast cancer incidence and mortality of the Canadian National Breast Screening Study: randomised screening trial. BMJ, 348, g366. https://doi.org/10.1136/bmj.g366.

    Article  PubMed  PubMed Central  Google Scholar 

  20. Nelson, H. D., Zakher, B., Cantor, A., Fu, R., Griffin, J., O’Meara, E. S., et al. (2012). Risk factors for breast cancer for women aged 40 to 49 years: a systematic review and meta-analysis. Annals of Internal Medicine, 156(9), 635–648. https://doi.org/10.7326/0003-4819-156-9-201205010-00006.

    Article  PubMed  PubMed Central  Google Scholar 

  21. Paul, A., & Paul, S. (2014). The breast cancer susceptibility genes (BRCA) in breast and ovarian cancers. Frontiers in Bioscience (Landmark Ed), 19, 605–618.

    CAS  Article  Google Scholar 

  22. Poirier, A. E., Ruan, Y., Volesky, K. D., King, W. D., O’Sullivan, D. E., Gogna, P., et al. (2019). The current and future burden of cancer attributable to modifiable risk factors in Canada: summary of results. Preventive Medicine, 122, 140–147. https://doi.org/10.1016/j.ypmed.2019.04.007.

    Article  PubMed  Google Scholar 

  23. Provencher, C., Milan, A., Hiallman, S., & D’Aoust, C. (2018). Report on the demographic situation in Canada - fertility: overview, 2012 to 2016. Ottawa, ON: Statistics Canada.

    Google Scholar 

  24. Rosenberg, P. S., Check, D. P., & Anderson, W. F. (2014). A web tool for age-period-cohort analysis of cancer incidence and mortality rates. Cancer Epidemiology, Biomarkers & Prevention, 23(11), 2296–2302. https://doi.org/10.1158/1055-9965.EPI-14-0300.

    Article  Google Scholar 

  25. Scaranelo, A. (2012). Breast screening with magnetic resonance imaging. Canadian Medical Association Journal, 184(16), E877. https://doi.org/10.1503/cmaj.110008.

    Article  PubMed  Google Scholar 

  26. Shields, M., & Wilkins, K. (2009). An update on mammography use in Canada. Health Reports, 20(3), 7–19.

    PubMed  Google Scholar 

  27. Shoemaker, M. L., White, M. C., Wu, M., Weir, H. K., & Romieu, I. (2018). Differences in breast cancer incidence among young women aged 20-49 years by stage and tumor characteristics, age, race, and ethnicity, 2004-2013. Breast Cancer Research and Treatment, 169(3), 595–606. https://doi.org/10.1007/s10549-018-4699-9.

    Article  PubMed  PubMed Central  Google Scholar 

  28. Tamimi, R. M., Spiegelman, D., Smith-Warner, S. A., Wang, M., Pazaris, M., Willett, W. C., et al. (2016). Population attributable risk of modifiable and nonmodifiable breast cancer risk factors in postmenopausal breast cancer. American Journal of Epidemiology, 184(12), 884–893. https://doi.org/10.1093/aje/kww145.

    Article  PubMed  PubMed Central  Google Scholar 

  29. Welch, H. G. (2009). Overdiagnosis and mammography screening. BMJ, 339, b1425. https://doi.org/10.1136/bmj.b1425.

    Article  PubMed  Google Scholar 

  30. Zakaria, D., & Shaw, A. (2019). Trends in mammography, hormone replacement therapy, and breast cancer incidence and mortality in Canadian women. Cancer Causes & Control, 30(2), 137–147. https://doi.org/10.1007/s10552-019-1127-3.

    CAS  Article  Google Scholar 

Download references

Acknowledgements

Darren Brenner is supported by a Canadian Cancer Society Capacity Development Award in Prevention (#703917).

Author information

Affiliations

Authors

Corresponding author

Correspondence to Darren R. Brenner.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

ESM 1

(DOCX 12 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Heer, E., Ruan, Y., Mealey, N. et al. The incidence of breast cancer in Canada 1971–2015: trends in screening-eligible and young-onset age groups. Can J Public Health 111, 787–793 (2020). https://doi.org/10.17269/s41997-020-00305-6

Download citation

Keywords

  • Breast neoplasms
  • Incidence
  • Canada
  • Age of onset
  • Pre-menopause

Mots-clés

  • Tumeurs du sein
  • Incidence
  • Canada
  • Âge de début
  • Préménopause