A Global Look at Breast Cancer Rates—and What That Means for You

"You have breast cancer."

It's a statement that changes lives all over the world. One moment, you might be concerned about a lump, but are largely unaffected. The next moment? You're faced with a slew of treatment options, unclear outcomes and the prospect of years worth of doctor visits, life-changing decisions and ongoing testing. Not to mention the symptoms, side effects and mental health challenges that accompany such a diagnosis.

But receiving a cancer diagnosis in one country isn't necessarily the same as hearing it in another. Differences in detection rates, treatment options and even ethnicity, not to mention access to insurance coverage, all affect outcomes. (We should note, this article is specifically discussing women's breast cancer. Men can suffer from the disease as well.)

While the United States might be one of the most medically advanced countries in the world, you may be surprised to learn that it has one of the highest incidence rates of breast cancer in the world—and the numbers are rising.

Here's what you need to know about how the U.S. (and other countries) stack up when it comes to worldwide breast cancer statistics.

Breast cancer is the most frequently diagnosed cancer worldwide

There's a reason breast cancer education and awareness continue to be important worldwide goals. According to a 2020 cancer statistics study published in American Cancer Society Journals, breast cancer surpassed lung cancer in 2020 to take the top spot as the cancer with the most new cases worldwide—a jaw-dropping 2.3 million new cases.

In fact, breast cancer accounts for 1 in 4 of all new worldwide cancer cases, and 1 in 6 of worldwide cancer deaths.

One of the factors that most sharply separates breast cancer incidence and mortality rates around the globe is a country's "transitional" status. Essentially, how developed a country is—whether it's considered a developed country that has a high life expectancy and education rates, good access to health care, and high gross national income. But the effects of whether a country has "transitioned" or is "transitioning" (developed or developing) on breast cancer aren't necessarily what you might expect.

Incidence rates of breast cancer are higher in transitioned countries

First, incidence rates of breast cancer are particularly high in developed countries. According to the 2020 cancer statistics, incidence rates are 88 percent higher in countries that are considered transitioned, such as the U.S., Australia, Canada and countries in Northern and Western Europe. In fact, Belgium has the highest incidence of breast cancer worldwide—as of 2019, roughly 189 diagnoses per 100,000 women.

The reason for such high incidence rates in transitioned countries tends to be based on three separate factors. First, detection (especially early detection) tends to be higher in transitioned countries because women (and men) often have better access to education and screening tools, including mammograms to identify breast cancers.

But beyond the ability to detect the disease, women in transitioned countries have hormonal and lifestyle factors that play a significant role in the increased incidence of breast cancer.

Incidence rates are 88 percent higher in countries that are considered transitioned, such as the U.S., Australia, Canada and countries in Northern and Western Europe.

First, the female hormone estrogen plays a big role in the incidence of breast cancer, and women in developed countries tend to make lifestyle decisions that can affect the presence of estrogen in the body. For instance, women who live in countries with a "Western" lifestyle tend to have an earlier onset of menarche, fewer total pregnancies (including a more advanced age for the first pregnancy), less breastfeeding, later onset of menopause and increased use of hormonal birth control. They're also more likely to use hormone replacement therapy. All of these factors play a role in breast cancers that are associated with hormonal changes.

Second, the overall lifestyle of women in Western countries tends to be much different from those in developing countries. Risk factors for breast cancer that are prevalent in Western countries include:

• Higher rates of obesity
• Poor nutrition and exercise habits
• Higher intake of alcohol

Also, life spans in developed countries tend to be longer, and the population tends to be older. Since age is a primary risk factor for breast cancer, it makes sense that a population that skews older would have a higher incidence of diagnosis. Transitioned countries tend to have an older population and a longer expected life span than transitioning countries.

Transitioning countries tend to have higher mortality rates

While the incidence of breast cancer is higher in developed countries, mortality rates average 17 percent higher in developing countries than in developed countries. In other words, if you live in the U.S., you might be more likely to receive a breast cancer diagnosis in your lifetime than someone living in Barbados—but those who receive a diagnosis in Barbados may be more likely to die of the disease than someone in the States (Barbados actually has the highest mortality rate in the world for breast cancer).

While factors for this discrepancy vary from country to country, lower mortality rates in developed countries can largely be attributed to early detection and access to better medical care and more advanced treatment options.

Melanesia has the highest mortality rate

Barbados is the single country with the highest mortality rate in the world (roughly 32.9 per 100,000 women), but as a region? Melanesia "boasts" the top spot. This region of island countries off the Northeastern coast of Australia includes Fiji, New Caledonia, Papua New Guinea, the Solomon Islands and Vanuatu.

As a group, these islands have a breast cancer incidence of 50.5 per 100,000 women—significantly lower than the geographically close Australia/New Zealand region, which records an incidence of 95.5 per 100,000 women. That said, Melanesia's mortality rate is a shocking 27.5 per 100,000 women—whereas its Australia/New Zealand counterpart is just 12.1 per 100,000 women.

So what gives? You might assume the proximity of Melanesia to Australia/New Zealand would result in similar incidence and mortality rates, but clearly there are significant differences.

Namely, island regions—like Melanesia, Polynesia and the Caribbean (where Barbados is located)—all tend to have higher breast cancer mortality rates.

These low-middle-income countries don't have as highly developed a medical infrastructure and access to screening or treatments as more developed countries. They also don't have the bustling and varied economic activity that's found in locations like Australia, New Zealand and Western Europe, which means the average income of citizens is substantially lower.

When more advanced care is needed for cancer treatment but isn't available on the island, it becomes much harder to seek out care given the isolated nature of these countries. While living on an island might seem like a dream come true, it's not always a perfect paradise, especially when considering healthcare access and resources.

Since 2007, incidence rates have been increasing in the United States

While the incidence of breast cancer stabilized in the U.S., Australia, New Zealand and Europe in the early 2000s, after rising rapidly in the 1980s and 1990s due to increased detection thanks to mammogram screenings, the plateau hasn't remained stable. Starting in 2007, there has been an increase of incidence rates of about 0.5 percent per year, with similar increases seen in other developed countries.

Now, some of the increased incidence can be attributed to an aging population that's receiving regular mammogram screenings. That's a good thing. But, there may be a link to the obesity epidemic that's certainly a cause for concern. Specifically, the breast cancer that's seeing increased incidence is estrogen receptor-positive cancer—the type of cancer that's affected by hormones. Given that individuals with higher body fat percentages are more likely to have higher levels of circulating estrogen, it makes some sense there's a relationship between body fat percentage and incidence of breast cancer. In other words, as you put on more weight, your risk of developing breast cancer increases.

But what's even more concerning is the evidence that the mortality rate increases substantially for premenopausal women who are obese when they're diagnosed with estrogen receptor-positive cancer.

Incidence rates are rising fast in developing countries

While there's a lot to be said for the educational, socioeconomic and political benefits that women receive as a country becomes more developed, the incidence of breast cancer does appear to increase as a country transitions from being a less-developed to a more-developed nation.

In particular, breast cancer incidence rates are increasing in South America, Africa and Asia as lifestyle and economic changes take place. For instance, as women have more options for family planning, reducing the number of children they has over their lifetime and delaying the age when they start having children—the incidence of breast cancer tends to increase. Likewise, as women begin taking on more sedentary (but more lucrative) work, physical activity tends to decrease as rates of obesity increase. And as established, these lifestyle behaviors play a role in the increased rates of breast cancer.

Specifically, according to a presentation on the Epidemiology of Breast Cancer in Africa, author Joe-Nat Clegg-Lamptey, M.B.B.S., professor of surgery at the University of Ghana Medical School, found that Zimbabwe saw an increase of almost 5 percent per year, while Mozambique experienced a rise of 6.5 percent per year.

Even more concerning, these diagnoses tended to be in a younger population of women (age 50 or younger). This may be explained by a younger overall population as compared to North America and Western Europe, but it could also be related to genetic factors.

Most diagnoses in Africa are for late-stage cancer

What's particularly distressing about cancer diagnoses in Africa is that so many were found in late stages. In fact, 77 percent of all staged cases were stage III or higher (meaning the cancer has already spread). This is likely due to limited access to mammogram screenings, education about breast self-checks and greater overall difficulty (and cost) in seeking and receiving health care.

Some estimates indicate up to one-third of deaths in sub-Saharan Africa could be prevented if these diagnoses were made earlier and access to treatment was better. Because, of course, later diagnoses lead to poorer long-term prognosis.

In Clegg-Lamptey's presentation, he notes that in regard to three types of cancers—colorectal, breast and cervical—the five-year survival rate in Gambia was less than 22 percent, and the five-year survival rate for breast cancer in Ghana was just 25 percent. But the women in Ghana who were able to catch their cancers at stage 0 or 1 had a survival rate higher than 90 percent. This is clear evidence that poor survival is linked to advanced disease and a tendency for late-stage diagnosis.

Ashkenazi Jewish people, regardless of worldwide location, are more likely to get breast cancer

Of course, some breast cancers have a very clear genetic link, and for women with an Ashkenazi Jewish heritage, this means an increased risk of breast cancer. That's because Ashkenazi Jewish people have high rates of the BRCA1 and BRCA2 gene mutations associated with breast and uterine cancers. This is why Israel and some European countries or regions tend to have a higher incidence of breast cancer.

What can we conclude from this data?

Regardless of where you live, the most important thing to remember is that early detection and treatment make a big difference to long-term survival.

Talk to your doctor about breast self-examinations and start scheduling regular mammograms. If you have a family history or other risk factors, your doctor may suggest starting your screenings at a younger age. And if you happen to live overseas, ask about the resources and educational materials available to the country's citizens. Awareness and access to health care play major roles in breast cancer detection and treatment—and you may be able to help improve both by acting as an advocate in your area.