(RxWiki News) It's commonly believed that breast cancer predominantly affects white women. Actually, certain ethnic groups have similarly high risks of developing the disease.
Young Asian and Pacific Islander women born in California carry greater risks of breast cancer than white women of the same age. And Filipinas may be at higher risk than African-Americans. These are the findings of a study that is dispelling what turns out to be common misperceptions.
"Asian women born in U.S. have high risk of breast cancer."
Prevalence (how often something occurs) rates suggest that Asian and Pacific Islander women have a relatively low breast cancer risk. However, these rates don't focus on young women, says study co-author Susan Hurley, a research associate at the Cancer Prevention Institute of California.
For the study, Hurley and associates studied data from previous research that linked breast cancer cases to California birth records from 1988 to 2004. The team looked at data from women born in California in the 1960s, including 3,799 women who were eventually diagnosed with breast cancer and 17,461 women who did not develop the disease. Participants were aged 20 to 44 years. The average age at diagnosis was 36.
To researchers' great surprise, the study showed that young California-born Asian and Pacific Islander women had about a 62 percent higher risk of breast cancer than young white women.
Women included in Asian/Pacific Islander populations are women of Japanese, Filipina and Chinese ancestry. They all exhibited higher breast cancer risks, says Hurley, though the reason why remains a mystery.
Ethnic heritage isn't the only risk factor for breast cancer. Others include the age a woman is when she has her first child, how many children she has, her pattern of breastfeeding and even her diet.
It's believed that Asian women born in the United States have higher rates of breast cancer than women born and living in Asia, says Hurley. It makes sense, then, that U.S.-born Asian women would have rates similar to their white counterparts.
That U.S.-born Asian women's rates are higher than white women, Hurley calls, "quite startling" and "difficult to explain."
She says more study is needed to see if similar rates are found outside of California and in older women.
Findings from this study were published in the journal Ethnicity & Disease