by Mona Jhaveri - February 8, 2022

In 2020, an estimated 19.2 million new cancer cases were diagnosed worldwide, and 9.9 million people died from the disease. While these numbers are staggering, they only tell part of the story; despite cancer being one of the leading causes of death in most countries, differences in cancer incidence rates, mortality rates, and treatment disparities exist between different regions of the world.

In this blog post, we’ll explore those differences in detail and try to answer some of the most pressing questions about cancer: why haven’t we found a cure for it yet? And how can we achieve that goal?

Let’s start with a simple breakdown of cancer statistics on each of the six populated continents.

Cancer Statistics By Continent

The five most common cancers in both sexes worldwide are lung, colorectal, breast, stomach, and prostate cancers. However, the distribution of these cancers varies by continent. Some world regions also have different cancer rates for other types of cancers.

The following cancer statistics are from the GLOBOCAN platform, supported by the World Health Organization.

Africa

The five most commonly diagnosed cancers in Africa are slightly different than the global ones:

  • Breast cancer
  • Cervical cancer
  • Prostate cancer
  • Liver cancer
  • Colon and rectal cancer

These five cancers account for about 47% of all new cancer cases diagnosed in Africa.

An extensive study further corroborated and extended these results, finding that the most common cancers in Africa are:

  • Bladder, breast, and liver cancers in Northern Africa.
  • Colorectal, lung, and prostate cancers in Southern Africa.
  • Cervical and esophageal cancers in East Africa.

The age-standardized incidence rate for all cancers in both sexes in Africa was 132.1 per 100,000 for the year 2020. The age-standardized mortality rate was 88.8 per 100,000, making this continent the least favorable one when it comes to the mortality-to-incidence ratio (MIR = 0.67).

MIR represents a crude measure of the relative cancer burden in a population and is calculated as the number of cancer deaths per 100,000 population divided by the number of new cases diagnosed per 100,000 population. It is most often used as a comparative measure between different populations or time periods.

The lower the MIR, the better the population is at avoiding premature cancer deaths.

Asia

The five most common cancers in Asia are:

  • Lung cancer
  • Breast cancer
  • Colorectal cancer
  • Stomach cancer
  • Liver cancer

Together, these cancers account for over 50% of all new cancer cases diagnosed in Asia.

The age-standardized incidence rate for all cancers in both sexes in Asia was 169.1 per 100,000 for the year 2020. The age-standardized mortality rate was 101.6 per 100,000. The mortality-to-incidence ratio (MIR = 0.60) is thus slightly better than in Africa.

Cancer incidence and mortality vary widely by region within Asia. Eastern and Western Asia have a higher cancer incidence than South-Eastern and South-Central Asia but a lower MIR.

Europe

Europe is in the middle of the pack when it comes to cancer. The five most common cancers in Europe are:

  • Breast cancer
  • Colorectal cancer
  • Lung cancer
  • Prostate cancer
  • Bladder cancer

Together, these cancers account for just over 50% of all new cases diagnosed in Europe.

The age-standardized incidence rate for all cancers in both sexes in Europe was 285.2 per 100,000 for 2020. The age-standardized mortality rate was 108.7 per 100,000. This gives a MIR of 0.38 – better than Asia, Latin America, and Africa, but worse than North America and Oceania.

As with the previous two continents, cancer incidence and mortality vary by region within Europe. Western and Northern Europe typically have a higher incidence rate than Eastern Europe but a lower MIR.

Latin America and the Caribbean

In terms of the five most common cancers, Latin America and the Caribbean is similar to Europe:

  • Prostate cancer
  • Breast cancer
  • Colorectal cancer
  • Lung cancer
  • Stomach cancer

These account for just over 49% of all new cases diagnosed in this region.

The age-standardized incidence rate for all cancers in both sexes was 186.5 per 100,000 for 2020. The age-standardized mortality rate was 86.5 per 100,000. This gives a MIR of 0.46 – better than Africa and Asia, but worse than Europe, North America, and Oceania.

Southern regions of Latin America – Argentina and Uruguay – as well as Cuba, Jamaica, and Haiti have higher incidence and mortality rates than Central America and the rest of the continent.

North America

In North America, the five most common cancers are:

  • Breast cancer
  • Lung cancer
  • Prostate cancer
  • Colorectal cancer
  • Melanoma skin cancer

Together, these cancers account for over 41% of all new cases diagnosed in North America.

The age-standardized incidence rate for all cancers in both sexes was 360.7 per 100,000 for 2020. The age-standardized mortality rate was 87.1 per 100,000. This gives a MIR of 0.24, putting North America in second place in terms of MIR, meaning that cancer kills significantly fewer people in North America than in most other regions.

Northern America is unique in that it only includes two countries: Canada and the United States. Even though there are differences in treatment access and health outcomes between specific populations of those countries, they perform very similarly when considered on a global scale.

Oceania

Finally, Oceania, including Australia and New Zealand, has the best cancer statistics of all the regions studied.

The five most common cancers here are:

  • Breast cancer
  • Prostate cancer
  • Colorectal cancer
  • Melanoma skin cancer
  • Lung cancer

Together, these cancers account for over 41% of all new cases diagnosed in Oceania.

The age-standardized incidence rate for all cancers in both sexes in Oceania was 404.6 per 100,000 for 2020. The age-standardized cancer mortality rate was 93.2 per 100,000. This gives a MIR of 0.23, making Oceania the region with the lowest MIR.

Of the countries in Oceania, Papua New Guinea has the lowest incidence and highest mortality rates, while it is the other way around in Australia. This means that, overall, Australia has the best cancer statistics in Oceania.

Reasons for these variations

Now that we have ranked all six populated continents according to their cancer statistics, we can explore some of the reasons for these variations.

One obvious reason is that different regions have different access to healthcare and cancer treatment. In high-income areas like North America and Oceania, people have better access to screening tests, diagnosis, and treatment options than in low- or middle-income countries.

Cultural differences, genetic factors, and the prevalence of cancer risk factors like smoking, physical activity, diet, and exposure to sunlight also play a role. For example, melanoma skin cancer is more prevalent in Oceania and North America than in other regions because of the high levels of sunlight exposure in those areas.

Let’s take a closer look at the differences in cancer detection and treatment between low-, middle- and high-income countries.

Screening Differences

Cancer screening is the process of looking for cancer in people who do not have any symptoms. Screening can find cancers early when they are easier to treat.

In high-income countries (such as the US, Canada, Western European Countries, Japan, Australia, etc.), screening is often done as part of regular health checkups. This includes tests like mammograms (breast cancer), Pap smears (cervical cancer), prostate-specific antigen (PSA) tests (prostate cancer), and colonoscopies (colorectal cancer).

People often do not have regular health checkups in low- and middle-income countries. This means that cancers are often diagnosed later when they are more difficult to treat.

Reasons for these discrepancies include a lack of awareness about cancer, its risk factors, and symptoms, as well as the cost of screenings. Healthcare costs are often too high for people in low- and middle-income countries, especially if universal healthcare coverage doesn’t exist.

Treatment Differences

There are five main types of cancer treatment: surgery, chemotherapy, radiation therapy, immunotherapy, and targeted therapy.

The type of treatment that a person receives depends on the cancer type, its stage (how far it has spread), and their overall health.

In high-income countries, people often have access to all five types of treatment. Additionally, high-income countries have well-funded healthcare systems with many specialists who can treat cancer and the latest medical technology.

In low- and middle-income countries, people often do not have access to all five types of treatment.

Kenya, for example, doesn’t offer any targeted therapy to its cancer patients. Surgery is available, but the cost of such surgery often exceeds what people can afford. Chemotherapy and radiation therapy are also available in a limited capacity and are usually not available in rural areas. Patients typically wait a long time (up to 8 months) to start treatment.

The situation is only slightly better in middle-income countries. While they have basic healthcare plans and cancer control programs, they often lack the latest medical equipment, cancer drugs, and specialists. Furthermore, plenty of countries struggle with corruption and mismanagement of funds, leading to a shortage of essential medical supplies.

Are we any closer to a world without cancer?

Given the differences in cancer incidence, mortality, and treatment quality between high-, middle-, and low-income countries, it’s clear that we’re not yet close to a world without cancer.

The year 2021 marked the 50th anniversary of the War on Cancer. The war was declared by then-US President Richard Nixon, who vowed to find a cure for cancer by signing the National Cancer Act of 1971.

In these five decades since then, what progress have we made? Why haven’t we found a cure for cancer yet?

Let’s take a closer look.

Why there is no cure for cancer yet

There are many reasons why we still don’t have a cure for cancer. Here are some of the main ones:

  • Cancer is a complex disease. There are many types of cancer – over 100 – and each behaves differently. This makes it difficult to find a single cure that works for all cancers.
  • Cancer is caused by mutations in our DNA. These genetic mutations can occur randomly or result from external factors like tobacco smoke, radiation, or chemicals. This means that not everyone who develops cancer will have the same mutations.
  • Cancer is evolving. Cancer cells can mutate and evolve, making them resistant to treatment.
  • Cancer cells are good at avoiding the body’s natural defense mechanisms.

All of this means that it will be a while before we find a cure for cancer. But with continued research and investment, we’re getting closer every day.

The progress we’ve made so far

At first glance, it may seem like nothing much has been accomplished in the past 50 years to treat cancer. However, there have been some significant advances made in cancer research over the last few decades:

  • The discovery of human oncogenes (genes that can cause cancer) and tumor suppressor genes (genes that help prevent cancer).
  • The discovery of targeted therapies, which are drugs that attack the specific genetic mutations that allow cancer cells to grow and spread.
  • The approval of the first monoclonal antibodies (immunotherapy drugs) to treat cancer, such as Rituximab.
  • Some new medications, like Imatinib, completely revolutionized how we treat certain cancers. Thanks to Imatinib, chronic myeloid leukemia is now a largely curable disease.
  • The development of new radiation therapies like proton therapy. This type of radiation doesn’t affect the healthy cells near the tumor as much as traditional radiation therapy, meaning it causes fewer serious side effects.
  • The approval of cancer prevention vaccines, such as Gardasil, can reduce the risk of developing cervical cancer.

Of course, this is far from an exhaustive list – but it gives you an idea of the progress made in the fight against cancer.

We still have a long way to go until we find a cure, but we’re getting closer every day with continued research and investment.

What can be done to achieve a world without cancer?

We could focus our attention on a few areas to achieve a world without cancer.

Global cancer control system

Pretty much the only way to ensure equal access to high-quality cancer care is to have a global cancer control system in place. This would involve setting up standards for cancer care that all countries would be required to meet.

Institutions such as the World Health Organization have already created frameworks for such systems, which include stepping stones such as:

  • Universal health care that provides everyone with access to basic cancer care.
  • Training and education for healthcare professionals on how to diagnose and treat cancer.
  • Equipping hospitals with the necessary tools and resources to provide high-quality cancer care.
  • Regulating the prices of cancer medications and treatments so that they are more affordable for people in low- and middle-income countries.
  • Tobacco control is essential for reducing the number of people who develop cancer.
  • Vaccination and prevention against common viruses that can cause cancer, like HPV, and more.

This is easier said than done, of course. This type of initiative will take a lot of work and cooperation from all sectors – governments, healthcare professionals, pharmaceutical companies, etc. – but with the right tools in place, it could be achievable.

Expedited and diverse clinical trials

In this COVID-19 era, we’ve seen how fast clinical trials can yield results. One of the rare positive outcomes of this pandemic has been the expedited development of new vaccines for COVID-19. This type of urgency needs to be brought to the fight against cancer.

Moreover, clinical oncology trials should be conducted on more diverse populations. This would mean including more people from different racial and ethnic backgrounds and people with disabilities. This would improve the quality of data that we collect from a clinical trial, but it would also help reduce the disparities in cancer care that exist today.

Better care for older cancer patients

By the year 2030, 1 in 6 people will be over 60. This means that we need to start preparing for the influx of older cancer patients.

One thing we can do is make sure that our healthcare system is equipped to handle their unique needs. This includes providing them with appropriate palliative care, which can help to improve their quality of life even if they’re not cured.

We also need to do more research on aging and cancer to understand better how the two interact. This will help us develop new treatments and interventions for older cancer patients.

Conclusion

Each world region has its unique cancer landscape, with different incidence and mortality rates and disparities in care. Regarding the six populated continents, Oceania has the lowest mortality-to-incidence ratio, while Africa has the highest. This means that Oceania has the best chance of curing cancer, while Africa has the worst.

In terms of cancer treatments, low- and middle-income countries often don’t have access to the same level of care as high-income countries. This is due in part to the high cost of cancer medications and treatments and a lack of resources and trained healthcare professionals.

That being said, we have seen some progress over the years. For example, the cancer death numbers have decreased in high-income countries. And while there are still disparities in cancer care between different regions and socioeconomic groups, we are slowly starting to close the gap.

The fight against cancer is a daunting task, but it’s one where we can’t give up. With the right tools and cooperation from all sectors, we can achieve our goal of finding a cure for cancer.

Join us in this fight by donating to our cancer-fighting causes. Every little bit helps!

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