BEIJING - While the prevalence of breast cancer among women in Asia is lower than it is in much of the world, those who are hit by it in China tend to develop the illness at a much younger age, according to a new epidemiology study.

The survey, conducted by the Cancer Foundation of China between 1999 and 2008, found most Chinese women who developed the disease did so between 40 and 49.

The survey sampled more than 4,200 patients from throughout the mainland.

Among them, nearly 40 percent were aged between 40 and 49, which was about 10 years younger than the age most women develop the disease in the West.

"The findings are significant for more targeted intervention efforts in the country, including raising public awareness, campaigns and breast cancer screening programs," said Professor Zhang Baoning of the Cancer Institute and Hospital, Chinese Academy of Medical Science.

For instance, breast cancer screening should be targeted at women starting at age 35, he told China Daily.

The survey also found that the mortality rate is rising in China while it has been declining since the 1990s in the West.

"They are more experienced in early detection and proper treatment, given that most Western countries started breast cancer screening programs in the early 1960s," he said.

In China, the government did not start its free breast cancer screening program for rural woman until 2008. There is not yet a free breast cancer screening program for urban residents but one is expected soon, said professor Shen Zhenzhou with Fudan University's Shanghai Cancer Center.

In recent years, the prevalence of breast cancer in China has been rising fast. He said that could be because more people have adopted Western lifestyles, including high-stress careers and high-cholesterol and high-fat diets.

During the past decade, the number of women with breast cancer has surged by more than 20 percent on the mainland, he said, noting that the rates have gone up by even more than that in major cities.

In Shanghai, the rates increased by 400 percent during past 30 years and the incidence of breast cancer now stands at 70 per 100,000, Zhang added.

Also, "the rise is particularly affecting younger women before the menopause compared with Western countries. Some clinical doctors have even reported cases of women with the disease who are less than 20," Shen noted.

The incidence rate among urban women is 40 per 100,000. In the countryside it stands at 15 per 100,000, according to the latest statistics from the Ministry of Health.

Worldwide, Asian countries are seen as having low rates of breast cancer according to the World Health Organization.

The United States, which has a rate of 101.1 per 100,000, is the most heavily affected country.

Generally speaking, Caucasian women are more likely than Asian women to get breast cancer, experts said.

However, international studies have found that breast cancer rates among Chinese women who have been in the US for more than 10 years are 80 percent higher than among those who just arrived. The rate of breast cancer cases among American-born Asian women is similar to that among American-born Caucasians.

China Daily