Breast Cancer Facts

Breast Cancer Facts

Incidence

  • There are more than twice as many new breast cancer cases annually than new cases of cancer in any other site.1
  • Breast cancer is the most common cancer in European women with an estimated incidence of 494,100 in 2012.2
  • Incidence in the EU-28 in 2012 was estimated to be 361,600. 2
  • 1 in 8 women in the EU-28 will develop breast cancer before the age of 85.3
  • An average of 20% of breast cancer cases in Europe occur in women when they are younger than 50 years old; 37% occur at age 50–64 and the remaining cases in women above this age.2 Breast cancer therefore affects many women during their years dedicated to working and raising a family.

Mortality and survival

  • Breast cancer has the highest mortality of any cancer in women worldwide.1
  • Breast cancer claims the lives of more European women than any other cancer.4
  • Estimated number of women who died from breast cancer in 2012: In Europe: 142,980, EU-28 member states: 91,5851
  • The average 5-year relative survival of European women diagnosed with breast cancer in 1995-1999 was 79.5%.5
  • Table

    Table. Estimated numbers and age-standardised breast cancer incidence and mortality rates* in women per 100,000 in 2012.2   *Age-standardised rate (W): A rate is the number of new cases or deaths per 100,000 persons per year. An age-standardised rate is the rate that a population would have if it had a standard age structure. Standardization is necessary when comparing several populations that differ with respect to age because age has a powerful influence on the risk of cancer. Source: Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, Rebelo M, Parkin DM, Forman D, Bray, F. GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. Lyon, France: International Agency for Research on Cancer; 2013. Available from: http://globocan.iarc.fr, accessed on 26/5/2015. Ref. 2.

Facts about lifestyle and breast cancer

  • The increasing number of breast cancer cases may be due to changes in lifestyle habits, increase in sedentary lifestyle, weight gain and obesity and sociological changes such as increasing age at first birth and decreasing number of children born to women.1

Physical activity and weight

  • Excess body weight and physical inactivity account for approximately 25–33% of breast cancer cases.6
  • There is an inverse relationship between obesity (BMI of 30 or higher) and breast cancer in pre-menopausal women and a direct relationship in post-menopausal women.1
  • Inactivity is estimated to cause 10-16% of all breast cancer cases.7
  • The effect of weight loss is independent of physical activity.7

Alcohol consumption

  • Meta analyses show that breast cancer risk increases by around 7-12% per unit of alcohol per day.8,9,10 Light drinkers, up to one alcoholic drink per day (which corresponds to 12 grams or 15 ml of pure alcohol) have a 5% higher breast cancer risk compared with non drinkers.11

Reproductive factors

  • Having children at a younger age (under 30), having several children, and breast-feeding for long periods of time reduces breast cancer risk.1
  • Having first menstruation at an early age and menopause at a late age increase the probability of developing breast cancer. For each year in delay of menarche the risk decreases by about 15% and for each year of delay of menopause it increases about 3%.1,12

Menopausal therapy and use of contraceptives.

  • There is a very clear connection between hormone replacement therapy (HRT) and the risk of developing breast cancer.13,14 In the Million Women Study, current users of HRT at recruitment were more likely than never users to develop breast cancer (adjusted relative risk 1.66)15 Breast cancer risk increases the longer HRT is taken. 13,14
  • Based on a comprehensive amount of evidence, the IARC has concluded that long-term combined estrogen-progestogen menopausal therapy causes cancers of the breast.1
  • The risk depends on the length of use of HRT and is reduced once treatment is stopped, levelling off 5 or more years after stopping treatment.12
  • Combined estrogen-progestogen oral contraceptives are associated with an increased risk of breast cancer, notably among young women.1
  • Women currently or recently taking oral contraceptives have a 15-25% higher risk of breast cancer compared with women who have never used oral contraceptives. This risk levels off 10 or more years after stopping oral contraceptive use.12

 

References:

  1. Stewart BW, Wild CP, editors (2014). World Cancer Report 2014. Lyon, France: International Agency for Research on Cancer
  2. Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, Rebelo M, Parkin DM, Forman D, Bray, F. GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. Lyon, France: International Agency for Research on Cancer; 2013. Available from: http://globocan.iarc.fr, accessed on 26/5/2015
  3. Curado MP, Edwards B, Shin HR, Storm H, Ferlay J, Heanue M et al. Cancer Incidence in Five Continents, Vol. IX, IARC Scientific Publications No. 160. IARCPress: Lyon: 2007.
  4. J. Ferlay et al. Cancer Incidence and Mortality Patterns in Europe: Estimates for 40 countries in 2012. Eur J Cancer 49 (2013) 1374–1403
  5. Berrino F, Verdecchia A, Lutz JM, Lombardo C, Micheli A, Capocaccia R; EUROCARE Working Group. et al. EUROCARE Working group. Comparative cancer survival information in Europe. Eur J Cancer 2009, 45(6): 901-8. <a href=”http://www.eurocare.it/DatabaseEU4/tabid/78/Default.aspx” target=”_blank”>EUROCARE 4 study
  6. The International Agency for Research on Cancer.
  7. The International Agency for Research on Cancer. Weight Control and Physical Activity. IARC Handbook of Cancer Prevention, Vol. 6. IARC: Lyon 2002.
  8. Collaborative Group on Hormonal Factors in Breast Cancer. Alcohol, tobacco and breast cancer – collaborative reanalysis of individual data from 53 epidemiological studies, including 58 515 women with breast cancer and 95 067 women without the disease. Br J Cancer 2002;87(11):1234-45.
  9. Allen NE, Beral V, Casabonne D, et al. Moderate Alcohol Intake and Cancer Incidence in Women. J Natl Cancer Inst 2009;101(5):296-305.
  10. Key J, Hodgson S, Omar R, et al. Meta- analysis of Studies of Alcohol and Breast Cancer with Consideration of the Methodological Issues. Cancer Cause Control 2006;17(6):759-70
  11. Bagnardi V, Rota M, Botteri E, et al. Light alcohol drinking and cancer: a meta-analysis. Ann Oncol2012;24(2):301- 8. 2008
  12. Boyle, P., Levin, B. (eds.). World Health Organisation. International Agency for Research on Cancer. World Cancer Report 2008.
  13. Women’s Health Initiative Study.
  14. Million Women Study.
  15. Million Women Study Collaborators. Breast cancer and hormone replacement therapy in the Million Women Study. Lancet 2003, 362: 419-27