Falling incident rates for many cancers is definitely positive news but current trends predict increased cancer rates across the globe. By 2030, the number of new cancer cases will have increased by 75 percent.

Previously, the Centers for Disease Control and Prevention reported that new cancer diagnoses have decreased in America each year from 2004 to 2008 by around 0.6 percent per year. While these are positive trends for Americans, some of these decreases in new cancer diagnoses are being offset by increased incidence rates in other parts of the world.

Research looking at future trends of cancer incidence was led by Freddie Bray, PhD, from the International Agency for Research on Cancer in Lyon, France. The researchers examined data collected from GLOBOCAN, which contains cancer incidence and death rate estimates for 184 countries. The number of new cancer cases could be as high as 22.2 million by 2030 compared to 12.7 million new cases in 2008.

The researchers created a "future burden scenario for 2030" by using GLOBOCAN data to understand cancer trends in countries by using the Human Development Index (HDI), which ranks countries based on life expectancy, education and gross domestic product per head of household. The researchers also factored in changing populations, age and cancer incidence rate changes for lung, stomach, liver, colon, breast and cervical cancers.

For high and very high HDI regions, like Brazil, Russia, the UK, America, Australia, Japan, Italy, Norway, Canada, Argentina and Saudi Arabia, female breast cancer, lung cancer, colon cancer and prostate cancer were responsible for 50 percent of all cancer incidence.

Medium HDI regions like China, Jordan, the Dominican Republic, Iraq, India and South Africa, esophageal cancer, stomach cancer and liver cancer were other common cancers in addition to the four previously mentioned types of cancer. The researchers note that these seven cancers amounted for 62 percent of the cancer burden in medium-to-very-high HDI countries.

Low HDI countries such as Kenya, Haiti, Nigeria, Bangladesh, Afghanistan and Zimbabwe, cervical cancer was more common than either breast cancer or liver cancer. The researchers noted the difference between types of cancer in HDI countries, higher HDI regions had cancers that were more based on lifestyle or obesity while lower HDI regions had more infection-based types of cancer.

While new cases of cervical and stomach cancer have decreased in medium and high HDI regions, those positive trends are countered by increases in the number of new female breast cancer, prostate cancer and colon cancer cases.

Because countries are constantly developing, many low or medium HDI countries will see improvements in economic terms and in quality of life by 2030 and that brings along new sets of risks. The developing countries may have decreases in infection-based cancers but may see increases in lifestyle cancers such as lung cancer and prostate cancer.

The 75 percent increase is just a projection and there are many factors that can change that number. For starters, the number of new lung cancer cases in developing countries could be reduced if strong anti-tobacco initiatives and intervention programs helped limit the number of new smokers in low-to-medium HDI regions.

The study was published in The Lancet.