Breast cancer rates have been steadily increasing among Asian-American women over the past 15 years, as the disease has seemed to stabilize in other racial groups, according to a study released this month.
Researchers say it calls attention to the need to understand how different health problems can affect various Asian-American populations.
"It's a shock to people how different that patterns are," Scarlett Lin Gomez, research scientist with the Cancer Prevention Institute of California (CPIC) and the lead author of the report, told NBC News.
Researchers examined breast cancer trends among women in the San Francisco Bay Area from seven different Asian-American groups from 1988 to 2013.
Women of South Asian (Indian and Pakistani), Vietnamese, and Southeast Asian (Cambodian, Laotians, Hmong, and Thai) descent showed the most dramatic increases in breast cancer rates.
"They also happen to be the most recently immigrated groups," Gomez said. "Their patterns are mirroring what we saw for Japanese Americans back in the 70s and 80s."
Breast cancer rates among Japanese Americans seem to have leveled off, more closely resembling the patterns among non-Hispanic white women.
And for certain groups, the tumors aren't being detected until later stages. Women of Filipino, Korean, and South Asian descent tend to be in more advanced stages of breast cancer by the time the disease is diagnosed, according to the study.
The recent findings reinforce what San Francisco State University (SFSU) Asian-American studies professor Mai-Nhung Le has observed in her own Vietnamese-American community.
Le's sister was diagnosed with late stage breast cancer when she was in her 30s and pregnant after her doctor assured her that Asian women don't get breast cancer, Le said.
"He waited for months until her OB-GYN said she needs to get tested," Le told NBC news. "When she did, it was too late. She had inflammatory breast cancer that had travelled through her lymph nodes."
Her sister died before her 40th birthday.
That loss inspired Le to study the needs of Asian-American and Pacific Islander (AAPI) breast cancer survivors. Compared to the general population, AAPI women reported more unmet daily physical needs, such as needing help with cooking, housework, and transportation. Le also noted the significance of CPIC findings that Vietnamese and Southeast Asian women are more likely to have breast cancer before age 50.
"If they're younger, they're going to lose a lot of potential earning," Le said, noting that one of the residual effects of the Vietnam War and subsequent refugee experience is that Vietnamese-American women are more likely to be the primary breadwinners in their family.
"I think there's going to be need for financial support and help with child rearing," she said.
Asian-American women may also be prone to a more aggressive type of breast cancer than other racial groups, the CPIC study found.
The cancer subtype caused by the HER2-Neu protein affected women of Filipino, Vietnamese, and Korean descent more than non-Hispanic white women, according to the study.
While the study didn't look into the reasons behind the increase in breast cancer among AAPI women, researchers said that the data points to the importance of more breast cancer support for Asian-American women.
Medical sociologist Grace Yoo, also a professor at SFSU, has studied breast cancer and social support among women of color, predominantly Asian-American women, in the Bay Area. Yoo and her colleagues found many patients needed spiritual support as well as tangible, informational, and emotional support as they faced their diagnosis.
"Stigma around breast cancer is still so prevalent in the Asian-American community. Women may not talk about it and then not receive the support that they need," Yoo told NBC News, adding that AAPI families need to be more open in talking about the disease.
That support can even be as basic as telling relatives about the family history of cancer so that younger generations are aware of genetic risks, Gomez said.
"Asian-American women with breast cancer talking with other Asian-American women with breast cancer can be incredibly supportive," Yoo said.