May 31, 2012 -- Worldwide cancer rates are set to jump more than 75% by 2030.
And these rates may increase even further -- by 90% -- among less developed countries, according to what one leading New York City cancer doctor calls an "eye-opening" new report in the journal Lancet Oncology.
If the new predictions hold, 22.2 million new cancer cases will be diagnosed in 2030, compared with 12.7 million in 2008.
The predictions are based on rates of new cancer cases and cancer deaths in 2008 from 184 countries worldwide. These findings were then used to project how the cancer burden is likely to shift by 2030.
Countries were ranked by their human development index (HDI), a standard measure of a country's developmental status that takes into account life expectancy, education levels, and economic factors. The U.S. is considered to have a very high HDI, while sub-Saharan Africa ranks much, much lower.
Many of these countries do not have accurate cancer registries, which can make it difficult to track what is going on now and what can be expected in the future.
Why Are Cancer Rates on the Rise?
"Populations are growing throughout the world and populations are aging, which is why the number of cancer cases and deaths are going up globally," explains researcher Nathan Grey, MPH. He is the national vice president for global health at the American Cancer Society in Atlanta.
The types of cancer that are -- or will be -- on the rise vary by a country's development status.
In the U.S., for example, rates of obesity-related cancers such as breast cancer and colon cancer are projected to rise. The U.S. is also still facing the lingering-effects of smoking-related cancers. In poorly developed countries such as sub-Saharan Africa, rates of cancers that are related to infection are high. These include cervical cancer, liver cancer, and stomach cancer.
"These countries are increasingly ramped up to deal with HIV, AIDS, and malaria, and are not thinking about cancer," Grey says.
But they need to start thinking about it now.
It is not hopeless. "We can vaccinate people in developing countries against HPV, the virus that is responsible for many types of cervical cancer," he says. Low-cost screening for cervical cancer is also possible. "Swabbing the cervix with vinegar and looking for abnormalities is incredibly cheap. We can train health care providers to do it and save a lot of lives."
Cancer Profiles Change as Countries Become More Westernized
David M. Nanus, MD, is the chief of the division of hematology and medical oncology at New York-Presbyterian/Weill Cornell Medical Center. He reviewed the findings for WebMD.
"There are two reasons we get cancer," he says. "One is infections. Hepatitis B infection will give you liver cancer and HPV infection will give you cervical cancer," he says. "The other cause is environmental. Breast, prostate, lung, and colon cancer are the big four, and they have all been shown to be more environmental than infectious."
What does that mean? It means that as countries become more developed and move toward a more Westernized way of life -- not exercising, eating an unhealthy diet, and smoking -- rates of these cancers will increase, Nanus says. This will occur against the backdrop of lower rates of cancers linked to infection.
Americans are a cautionary tale, he says. "Globally, there has to be a greater emphasis on lifestyle prevention and getting the message across that the Western diet in America is not as great as it is made out to be."
There could be a double whammy. Developing countries will start seeing the same cancers that Westernized countries are seeing, but they won't have the same access to state-of-the-art health care. "There will be a peak in cancers and more deaths due to differences in health care."
Leslie Bernstein, PhD, has seen this shift coming. She is an epidemiologist at the City of Hope Cancer Center in Duarte, Calif.
"As we control those cancers which are related to infection like liver cancer and stomach cancer, we are going to see more cancers that are environmentally caused, meaning that they are related to lack of physical activity, obesity, smoking, and things like that," she says.
"These cancers take over as countries become more and more Westernized."