Definition of breast cancer

‘Breast cancer is a malignant tumor that has developed from cells in the breast. It usually begins either in the cells of the lobules (the milk-producing glands) or in the ducts that drain the milk from the lobules to the nipple. Less commonly, breast cancer can begin in the stromal tissues, which include the fatty and fibrous connective tissues of the breast’ (ECIS 2020). The most common types of breast cancer are ductal invasive breast cancer (invasive ductal carcinoma, and invasive lobular carcinoma) and ductal carcinoma in situ (DCIS). In IDC and ILC, tumoral cells spread from the duct to the surrounding tissues and can also spread to other parts of the body (most commonly to lung, liver, bones and brain) (CDC 2022; WHO 2023). DCIS, also called intraductal or stage 0 breast cancer, is a pre-invasive condition where cancerous cells have not started to spread from ducts to the surrounding tissues (ACS 2021; Cancer Research UK 2023).

Breast cancer may grow without showing signs or symptoms. When symptoms of breast cancer arise, they can vary and may include: the appearance of a painless breast mass or thickening; thickening, redness or warmth of the skin, or a rash; enlarged lymph nodes in the armpit(s); focal breast pain; nipple discharge or progressive nipple inversion (WHO 2023). 

Incidence of breast cancer in the European Union

According to the European Cancer Information System (ECIS) breast cancer factsheet, it is estimated that breast cancer accounts for 13.8% of all new cancer cases diagnosed in the EU in 2022, which makes it the most frequently occurring cancer (ECIS 2023). Moreover, it is estimated that 29.4% of new cancer cases in women are of breast cancer (ECIS). It is the most commonly diagnosed cancer type and the leading cause of cancer death in women worldwide (WCRF, AICR 2018). One in eleven women aged 0-74 years will develop breast cancer (ECIS). EU 2020 estimates of age standardised incidence rate (ASR) of female breast cancer is 142,8 per 100 000 (ECIS) (Table 1).

Table 1: Age-standardised incidence rate of breast cancer 

Factors related to breast cancer risk

Breast cancer is linked to various risk factors. Non-modifiable risk factors include family history of breast and/or ovarian cancer, personal history of proliferative benign breast disease, inherited mutations of certain genes such as BReast CAncer gene 1 and 2 (BRCA1 and BRCA2), dense breasts on mammogram, older age, greater birthweight (for premenopausal breast cancer) and greater adult attained height (WHO 2023, WCRF, AICR 2018). 

Reproductive factors including early menarche (before the age of 12), late natural menopause (after the age of 55), not bearing children and first pregnancy over the age of 30 all result in longer lifetime exposure to endogenous oestrogen and progesterone and increase the risk of breast cancer (ACS 2019). Prolonged use (more than 5 years) of combined oral contraceptives or postmenopausal hormone-replacement therapy (particularly estrogen plus progestin) are also associated with increase in the overall breast cancer risk.

Environmental risk factors for breast cancer are in-utero exposure to the drug diethylstilbestrol and prior exposure to ionizing radiation at the level of the chest or breasts (WHO 2023, IARC WHO 2020).

Modifiable risk factors include alcohol consumption, body weight, physical (in)activity, smoking, and nutrition.

Table 2 summarises data on the main modifiable risk factors for breast cancer.

Table 2: Modifiable risk factors related to breast cancer 

Disease and economic burden related to breast cancer

According to the Global Burden of Disease 2019 study, nearly 115 000 deaths were due to breast cancer in the EU countries in 2019, with the vast majority of them (nearly 114 000) in women (IHME 2023). Additionally, more than 2.5 million Disability Adjusted Life Years (DALYs) are due to breast cancer (IHME 2023).

View visualisation: DALYs map and data table 

View visualisation: Mortality map and data table 

The economic burden of breast cancer in the European Union in 2009 was €15 billion (Luengo-Fernandez 2013), accounting for 12% of overall cancer costs. Breast cancer accounted for the highest health-care costs (€6.73 billion; 13% of all cancer-related health-care costs). Table 4 shows the cost per person and adjusted cost per person (adjusted for price differentials with the purchasing power parity method) for breast cancer in the EU in 2009.

Productivity losses due to breast cancer have been estimated to be €3.25 billion, accounting for 8% of productivity losses because of all cancers (Luengo-Fernandez 2013).

Table 3: Healthcare cost and adjusted healthcare cost of breast cancer in the EU in 2009 

Policies related to the prevention of breast cancer

Many EU Member States have introduced strategies to tackle cancer in general. Such strategies mainly focus on addressing its risk factors (primary prevention) and, when relevant, on detecting cancer earlier (secondary prevention).

Primary prevention of breast cancer (breast cancer risk factors)

At EU level, one of the main pillars of Europe’s Beating Cancer Plan (EC 2021) is the prevention pillar, including actions to improve health literacy, to reduce tobacco and harmful alcohol consumption, to improve access to healthy diets and physical activity.  Breast cancer, as many other forms of cancer, shares risk factors with other major non-communicable diseases.

Policy recommendations addressing nutritional risk factors, physical activity and sedentary behaviour, alcoholic beverages and smoking are listed in the dedicated pages of this Health Promotion and Disease Prevention Knowledge Gateway. 

Secondary prevention of breast cancer (screening)

Breast cancer screening aims to the early detection of breast cancer. Despite the fact that the incidence rates of breast cancer have increased over the past years, mortality rates have declined, which is indicative of earlier diagnosis and better treatments, which consequently leads to lower mortality rates (WHO 2023). The European breast cancer guidelines on screening and diagnosis recommend implementing an organized population-based screening programme for early detection of breast cancer in asymptomatic women (EC 2023). 

According to the European breast cancer guidelines, in the context of an organised, population-based cancer screening programme:

• No mammography screening is suggested for asymptomatic women aged 40-44 with an average risk of breast cancer (conditional recommendation, moderate certainty of the evidence)
• Mammography screening every 2-3 years is suggested for asymptomatic women aged 45-49 with an average risk of breast cancer (conditional recommendation, very low certainty of the evidence)
• Mammography screening every 2 years is recommended for asymptomatic women aged 50-69 with an average risk of breast cancer (strong recommendation, moderate certainty of the evidence)
• Mammography screening every 3 years is suggested for asymptomatic women aged 70-74 with an average risk of breast cancer (EC 2023) (conditional recommendation, very low certainty of the evidence).

These guidelines have been integrated into the new Council Recommendation on cancer screening (Council Recommendation of 9 December 2022), adopted in December 2022 as part of the new EU Cancer Screening Scheme, as announced through Europe’s Beating Cancer Plan.

References

Overview of the references to this brief