The World Health Organization also reported that cancer deaths had risen by 8.4 percent from 2008 to 2012, hitting 8.2 million.
The "GLOBOCAN 2012" report by the International Agency for Research on Cancer (IARC), a France-based arm of the WHO, was based on data on 28 forms of cancer in 184 countries.
The most commonly diagnosed cancers worldwide were those of the lung (13 percent), breast (11.9 percent), and colorectum (9.7 percent).
The biggest killers were lung cancer, responsible for almost one-fifth of total deaths, followed by cancer of the liver (9.1 percent) and stomach (8.8 percent).
The WHO said it expected the number of new cancer cases to rise to 19.3 million per year by 2025, due to the growth and ageing of the global population.
In 2012, close to 57 percent of all new cancer cases, and almost 65 percent of cancer deaths occurred in the world's less-developed regions, and these trends are likely to increase, it said.
The report spotlighted the sharp increase in cases of breast cancer around the world.
In 2012, 1.7 million women were diagnosed with breast cancer, and there were 6.3 million women alive who had been diagnosed with breast cancer in the previous five years, it said.
Since 2008, the incidence of breast cancer has increased by more than 20 percent, while mortality was up by 14 percent.
Breast cancer is the most common cause of cancer death among women, with 522,000 deaths in 2012. It now represents one in four of all cancers in women.
"Breast cancer is also a leading cause of cancer death in the less developed countries of the world," David Forman, head of the IARC's cancer data division, said in a statement.
"This is partly because a shift in lifestyles is causing an increase in incidence, and partly because clinical advances to combat the disease are not reaching women living in these regions," he added.
In addition, cervical cancer is a huge concern, notably in poor nations.
In sub-Saharan Africa, 34.8 new cases of cervical cancer are diagnosed per 100,000 women annually, and 22.5 per 100,000 women die from the disease. These figures compare with 6.6 and 2.5 new cases per 100,000 women, respectively, in North America.
Lack of access to effective screening and to services that facilitate early detection and treatment are to blame, the WHO said.