Breast Cancer Rates Reported Rising Among Asian-American Women

Breast cancer rates among Asian-American women are rising, especially in Japanese-American women, according to researchers at the University of Southern California.

Researchers looked at cancer cases reported in the mid-to-late 1990s to the Los Angeles Cancer Surveillance Program (CSP). Breast cancer rates in Los Angeles are considered to be similar to rates nationwide.

Investigators found that the rates of breast cancer for Japanese and Filipino women were about double those for Chinese and Korean women, and rates rose during the 1993-1997 period for all except Chinese women, according to the study published in the International Journal of Cancer.

"Although Asian-American women in the past have had low breast cancer rates, that appears to no longer be the case," said Dennis Deapen, professor of preventive medicine and director of the Los Angeles County CSP. "And if trends from the 1990s have continued, rates among Japanese-American women in Los Angeles County may have surpassed those of non-Hispanic white women, who have historically had the highest rates of breast cancer."

Findings of the study include:

• Among Asian women 50 years or older, diagnosed cases of breast cancer increased about 6.3 percent per year over the five-year period.
• Among non-Hispanic white women 50 years or older, diagnosed cases of breast cancer increased about 1.5 percent per year during the same period;
• In 1997, Asian-American women had 78 cases per 100,000 women. Non-Hispanic white women had about 129 per 100,000 and Hispanics had about 64 per 100,000;
• In 1997, Japanese women had 114 cases per 100,000, Filipinos had had about 98 per 100,000, Chinese women had about 51 per 100,000 and Korean women had about 45 per 100,000.

"Breast cancer incidence for Japanese-American women in Los Angeles County is the highest reported anywhere in the world," said Deapen. In Japan, studies have shown that the incidence of breast cancer has increased dramatically, more than doubling from 1960 to the last 1980s.

Researchers speculate that a more Westernized lifestyle has influenced the increased numbers of breast cancer victims, including having fewer children, engaging in less physical activity and increased obesity. Japanese women are also eating more fats and fewer soy products.

Prior research has also shown that when Asian women migrate to the United States, the risk of breast cancer increases in subsequent generations. Among the groups analyzed in this new study, Japanese were the first population to migrate to Los Angeles County, followed by Filipinos, Chinese and Koreans.

Although Asian-American women have traditionally had lower-than-average risk of breast cancer, doctors need to know that their rates are rapidly rising and screening is just as important for them as it is for other groups, concluded the researchers.

Other sources: International Journal of Cancer