Breast cancer

Breast cancer is the most common cancer among women. 4076 women were diagnosed with breast cancer in 2023.

Last updated: 1/14/2025

The incidence of breast cancer has increased significantly in recent decades. In 2022, there was more than twice as much breast cancer among Norwegian women as in 1958. Every year, 25-30 men are affected by breast cancer, and the incidence for men has been stable for the past 50 years.

For those affected by this disease, the prospects of survival are steadily improving, and those who do not recover live longer with the disease.

In addition to previous diagnosis, great progress has been made in the treatment of breast cancer in recent years.

New cases

4076 women and 35 men contracted breast cancer in Norway in 2023. The number of cases per 100,000 people is 135.2 for women and 1.0 for men.

In the period 2019-2023, 57.6 per cent of cases in women were detected in stage I (early, local stage), while 38.7 per cent were detected in stage II and 13.2 per cent in stage III. 5.7 per cent had distant metastasis, stage IV, at the time of diagnosis, while 20 per cent had an unknown stage.

Aging

The median age for breast cancer is 62 years, which means that half of all those diagnosed are over 62 years of age.

Incidence of breast cancer by age at diagnosis, year of diagnosis 1983–2023. From Figure 2.4 in the Breast Cancer Regisry's annual report 2023. (Norwegian only)

The figure shows that for women under 30 there is a steady incidence throughout the period. For the age groups 30–39 years and 40–49 years, a slight increase has been seen in recent years. There has been a marked increase in the incidence for the age group 50–69 years, which is related to the gradual introduction of the Mammography program from 1996, combined with an increase in hormone treatment during menopause.

Due to covid-19 with reduced activity in the Mammography program in 2020, there was a decrease in the number of diagnoses. In 2021, the incidence increased significantly in this age group, it has flattened out in 2022 and fallen in 2023. The incidence of breast cancer in Norway has been fairly steady for the age group 70+ from 1983–2009, but we have seen an increase in recent years, apart from 2022 to 2023, there has been a decline in the incidence for the oldest age groups.

Survival

Breast cancer survival has gradually improved, and 9 out of 10 women affected are alive 5 years after diagnosis.

Five-year relative survival in the period 2019-2023 totals (all stages) is 92.6 percent. The survival rate for patients with distant metastasis is significantly lower; 41.8 per cent.

Relative survival of breast cancer up to 15 years after diagnosis divided by age in the period 2019-2023. Fra fig. 8.2-L i Cancer in Norway 2023.

Survivors with breast cancer

At the end of 2023, there were 59.089 people who had recovered from or were living with breast cancer diagnosed over the past 15 years.

More than 27,000 of these were diagnosed more than 10 years ago.

Number of deaths

619 women and 7 men died of breast cancer in Norway in 2022.

Development over time

Trends in incidence (red), mortality (pink) and 5-year relative survival (brown) of breast cancer among women in the period 1965-2023. Fra Cancer in Norway 2023, fig. 9.1-M.

There is a steady incidence for the 70+ age groups from 1985-2008, and there is an increase in recent years. There is a marked increase in incidence for the age group 50-69 years following the gradual introduction of breast cancer screening from 1996, combined with an increase in hormone therapy during menopause. There is a steady increase in the incidence rates for the age group 30–49 years throughout the period.

The proportion of women who are alive 5 years after being diagnosed with breast cancer has increased sharply. In the late 1970s, 5-year relative survival was 73.4 percent. In the last five-year period, survival has increased to more than 90 per cent.

There is a marked decline in breast cancer mortality from the mid-90s to the present.

Norwegian Breast Cancer Registry

The Breast Cancer Registry was granted national status in 2013, but has registered data since 2009. The Cancer Registry of Norway is responsible for data processing, and a professional council has been established in the registry.

The purpose of the Breast Cancer Registry is to strengthen the quality of health care for patients with breast cancer. The registry shall also conduct, promote and provide a basis for research to develop new knowledge about the causes, diagnosis and course of cancer, as well as treatment effects.

Find annual reports for the Breast Cancer Registry (Norwegian only)

Patient-reported results

In 2019 and 2020, the Cancer Registry of Norway worked on planning and building infrastructure for collecting PROMs, including integration with ePROMs, which is the national solution for collecting PROMs.

Collection of PROM and PREM data for breast cancer began in the fall of 2020 for women diagnosed in 2020 through a permanent, three-year population survey on health and quality of life. For PROMs, women diagnosed with breast cancer are compared with a control group with women without breast cancer, but with matching age and place of residence.

Population-based health surveys

See more results on patient-reported outcome measures in the annual report for the Breast Cancer Registry

Breast cancer screening

Some of the increase in the incidence of breast cancer can be attributed to the Mammography Programme, the organised screening against breast cancer offered to Norwegian women between 50-69 years. The programme detects more cases of cancer at an earlier stage than if the woman had waited until the symptoms appeared. This most likely improves survival for those affected.

Risk factors

There is no single reason why more and more women are getting breast cancer.

However, we know of several risk factors for the disease. The risk of breast cancer increases with age. Most cases occur after the age of 50. Therefore, Norwegian women are invited to mammography screening from about the age of 50. Women who have breast or ovarian cancer in their family may also be at increased risk. Between 5 and 10 percent of breast cancer cases may be due to heredity. How early children are born, how many babies are born, and the extent to which breastfeeding children have also been shown in large studies to be associated with breast cancer risk.

Several lifestyle factors can increase the risk of getting breast cancer. Obesity after menopause, alcohol intake and lack of physical activity can increase the risk. Long-term use of hormone supplements with the combination of oestrogen and progestogen in connection with menopause also increases the risk of breast cancer.

Read about risk factors and prevention for breast cancer on kreftforeningen.no

Read about cancer prevention on kreftregisteret.no

Steps You Can Take to Reduce Your Risk of Getting Breast Cancer

Have a healthy diet
Keeping a healthy body weight
Drink as little alcohol as possible
Be physically active
Avoid long-term use of estrogen supplements associated with menopause
Examining their breasts themselves

How to examine your breasts

By participating in the mammography programme, breast cancer can be diagnosed and treated at an early stage

Read about the mammography programme on kreftregisteret.no

Questions about cancer

The Cancer Registry of Norway is a research institution. Our professionals therefore do not answer questions about diagnosis, assessment, treatment and follow-up from patients or their relatives.