Breast cancer is one of the most common cancers among women worldwide. However, the rates seem to vary by ethnicity and geographical location.
Breast cancer makes up around 25% of all new cancer diagnoses in women globally. In fact, the World Cancer Research Fund (WCRF) estimate that doctors issued over 2 million new diagnoses of this cancer across the world in 2018.
Survival rates vary worldwide but are improving overall. In countries with advanced care, such as the United States, people with localized breast cancer are 99% as likely as people without cancer to live for 5 years beyond diagnosis.
This 5 year relative survival rate drops to 27% if the breast cancer spreads to distant sites in the body.
In this article, we take a look at various breast cancer statistics for the global population and that of the U.S. in particular.
Around the world, breast cancer is now the leading cause of cancer-related deaths in women. It accounts for around 15% of deaths from cancer.
In developed countries, breast cancer is second only to lung cancer for cancer-related deaths in women.
In 2018, Belgium had the highest rate of breast cancer in the world, with 113.2 diagnoses per 100,000 adult women.
However, the majority of new breast cancer diagnoses and deaths now occur in developing countries — partly due to having a larger portion of the world’s population. The rates have been steadily rising in these nations over recent decades.
Breast cancer incidence, or the number of cases per 100,000 women, is still lower overall in developing countries than in the West.
However, death rates from the condition are higher. The World Health Organization (WHO) attribute these disproportionately high death rates to later stage diagnoses and limited access to treatment.
In more medically advanced countries, it is likelier that healthcare professionals detect breast cancer early and that women can start treatment as soon as possible following diagnosis.
This table shows the prevalence of breast cancer diagnosis and death in several parts of the world:
|Percentage of the world population||Percentage of new breast cancer diagnoses||Percentage of breast cancer deaths|
|U.S. and Canada||5%||15%||9% |
Incidence rates per 100,000 women
According to the WCRF, the three countries with the highest incidence of breast cancer are:
- Belgium: 113.2
- Luxembourg: 109.3
- The Netherlands: 105.9
A 2015 study in the journal Cancer Epidemiology, Biomarkers & Prevention reported data from 2006–2007 that suggest that the lowest three incidence rates came from:
- Thailand: 25.6
- Algeria: 29.8
- India: 30.9
Higher body fat may therefore have links to a higher risk of breast cancer, according to the American Cancer Society. For this reason, increasing rates of obesity could account for part of the global increase in breast cancer rates.
Scientists have not yet proven any direct links between diet and breast cancer. However, many believe that diet plays a role in raising the risk of cancer.
Breast cancer is the second most common cause of cancer-related death in the U.S. among white, black, Asian/Pacific Islander, and American Indian/Alaska Native women. It is the leading cause of cancer-related death for Hispanic women in the U.S.
However, the rates per 100,000 women differ greatly among certain ethnicities.
The Susan G. Komen Breast Cancer Foundation explain that the following are the breast cancer incidence rates per 100,000 women in the U.S. between 2012 and 2016:
- White: 130.5
- Black: 124.0
- Hispanic: 100.1
- Asian/Pacific Islander: 97.2
- American Indian/Alaska Native: 79.5
These differences may be down to disparities in reproductive patterns. For example, the following risk factors for breast cancer vary by ethnicity:
- a woman’s age at the time of their first period and pregnancy
- their age at menopause
- body weight
- breastfeeding habits
- total number of childbirths
- use of hormonal therapy during menopause
Hormonal changes may have links to the possible increase in breast cancer incidence worldwide. These hormonal changes may relate to:
- a woman’s number of pregnancies
- their age at the time of their first pregnancy
- the number of children they have
- their use of supplemental hormones
A woman’s breast cancer risk is higher if she has her first full term pregnancy after 30 years of age or never has a full term pregnancy.
This may be due to higher total levels of estrogen and progesterone that circulate during menstrual cycles. Pregnancy and breastfeeding reduce the number of menstrual cycles and overall exposure to these hormones during a woman’s lifetime.
Similarly, if a woman begins menstruating at a younger age or completes menopause at a later age, she experiences more menstrual cycles. This contributes to higher hormonal exposure and an increased lifetime risk of breast cancer.
Taking certain supplemental hormones may also increase the risk of breast cancer, including the use of estrogen and progestin during menopause. However, these can only increase a woman’s breast cancer risk after 5 years of use.
Certain birth control pills containing estrogen and progestin might also increase the risk of breast cancer. The risk is higher if the woman has a family history of breast cancer, has a breast cancer gene, or has had abnormal breast cells in the past.
Making certain lifestyle changes may bring down a woman’s risk of developing breast cancer. These include:
- taking steps to control body weight
- avoiding or limiting hormone therapy during menopause
- limiting alcohol consumption
- getting regular exercise and avoiding a sedentary lifestyle
However, it is not possible to control many of the factors that contribute to a woman’s breast cancer risk. These factors include:
- being 55 years of age or older
- having the BRCA1 or BRCA2 genes or certain other mutations
- having dense breast tissue
- going through menopause later in life or starting menstruation at a younger age
It is important to remember that many women who have a healthful lifestyle and no known risk factors still develop breast cancer.
Early detection is key
Scientists still do not fully understand many aspects of breast cancer. Medical experts tend to recommend screening and watching for breast changes to support early detection and treatment.
Women can talk to their doctors about when and how often mammograms are necessary, based on their individual risk factors. They should also see a doctor if they notice any breast changes, such as:
- skin changes
- nipple changes
- any unusual sensations in the breast area
Early detection of breast cancer means a better chance of successful treatment.
At what age should I start attending breast cancer screenings?