Christina Kashiwada was on a business trip in the summer of 2018 when she noticed a small, itchy lump in her left breast.
At first, she didn’t pay attention to it. She did routine self-exams and continued to make medical appointments. But a family member encouraged her to get checked out. mammographyShe followed the advice and learned she had stage 3 breast cancer, a revelation that stunned her.
“I’m 36, right?” said Kashiwada, a civil engineer in Sacramento, Calif. “Nobody thinks about cancer.”
In 2021, about 11,000 Asian and Pacific Islander women were diagnosed with breast cancer, and about 1,500 died from it. The latest federal data show that the rate of new breast cancer diagnoses among Asian and Pacific Islander women — a group that once had relatively low diagnosis rates — is increasing much faster than many other racial and ethnic groups. The trend is particularly pronounced among young women like Kashiwada.
About 55 out of every 100,000 Asian and Pacific Islander women under age 50 were diagnosed with breast cancer in 2021, higher than the rate for Black and Hispanic women and comparable to that for white women, according to age-adjusted data from the National Institutes of Health. (Hispanic people can be any race or combination of races, but are grouped separately in these data.)
The rate of new breast cancer cases among Asian American and Pacific Islander women under age 50 increased by about 52% between 2000 and 2021. Rates for AAPI women ages 50 to 64 increased by 33%, and rates for AAPI women ages 65 and older increased by 43% during that time. By comparison, the rate for women of all ages, races, and ethnicities increased by 3%.
Researchers have noticed this trend and are trying to understand why it is occurring in this ethnically diverse group. They believe the answer is complex, ranging from cultural changes to stressful lifestyles, but they admit it remains a mystery and is difficult for patients and their families to talk about because of cultural differences.
Helen Chew, director of the breast cancer clinical program at UC Davis Health, said the Asian American diaspora is so large and diverse that simple explanations for the rise in breast cancer are not obvious.
“It’s a real trend,” Chew said, adding that “it’s hard to pinpoint exactly why. Is it because we’re seeing an influx of people who have less access to care? Is it because of a lot of cultural things that make them not want to come in if they see something on their breast?”
Solving this mystery is urgent because it is costing lives. While women of most ethnic and racial groups are experiencing sharp declines in breast cancer mortality rates, about 12 out of every 100,000 Asian American and Pacific Islander women of all ages died of breast cancer in 2023, essentially the same death rate as in 2000, according to provisional age-adjusted data from the Centers for Disease Control and Prevention. The breast cancer death rate for all women during that period fell 30%.
The CDC does not break out breast cancer death rates for different groups of Asian American women, such as those of Chinese or Korean descent. It has, however, begun to distinguish between Asian American and Pacific Islander women.
Nearly 9,000 Asian American women died of breast cancer between 2018 and 2023, compared with about 500 Native Hawaiian and Pacific Islander women. However, breast cancer death rates were 116% higher among Native Hawaiian and Pacific Islander women than among Asian American women during this period.
Rates of pancreatic, thyroid, colon and endometrial cancer, as well as non-Hodgkin lymphoma, have also increased significantly among Asian-American and Pacific Islander women under age 50, according to NIH data. Yet breast cancer is far more common among young Asian-American women than any of these other types of cancer, which is particularly concerning because younger women are more likely to face more aggressive forms of the disease, with high mortality rates.
“We’re seeing an increase of almost 4% per year,” said Scarlett Gomez, a professor and epidemiologist at the Helen Diller Family Comprehensive Cancer Center at the University of California, San Francisco. “We’re seeing an increase even greater than 4% per year in Asian/Pacific Islander women under age 50.”
Gomez is one of the lead researchers on a large study of the causes of cancer in Asian Americans. She says there isn’t enough research yet to know what’s driving the recent increase in breast cancer. The answer may be multiple risk factors over a long period of time.
“One of the hypotheses we’re studying is the role of stress,” she said. “We’re asking all sorts of questions about different sources of stress and different modes of coping across the lifespan.”
It’s probably not just that there are more screening“We looked at trends by stage at diagnosis and we see similar rates of increase across all stages of the disease,” Gomez said.
This trend may be related to Asian immigrants adopting lifestyles that put them at higher risk, says Veronica Setiawan, a professor and epidemiologist at the University of Southern California’s Keck School of Medicine. Setiawan is a breast cancer survivor who was diagnosed a few years ago at age 49.
“Asian and American women are becoming more Westernized, so they’re going through puberty earlier now, they’re going through adolescence earlier. [the first menstrual cycle] “Later giving birth, delaying childbearing, not breastfeeding, all of these are associated with increased risk,” said Setiawan, who is working with Gomez on the cancer study. “Maybe later giving birth, delaying childbearing, not breastfeeding, all of these are associated with breast cancer risks.”
Moon Chen, a professor at the University of California-Davis and an expert on cancer health disparities, added that only a tiny fraction of NIH funding goes to cancer research among Asian Americans.
Whatever the cause, this trend has created years of anguish for many patients.
Kashiwada underwent a mastectomy after being diagnosed with breast cancer. During the surgery, doctors at UC Davis Health discovered that the cancer had spread to the lymph nodes in her armpit. She underwent eight rounds of chemotherapy and 20 sessions of radiation.
Throughout her treatments, Kashiwada hid her ordeal from her grandmother, who had helped raise her. Her grandmother never knew about the diagnosis. “I didn’t want her to worry about me or have any added stress,” Kashiwada said. “She probably wouldn’t sleep if she knew this was happening. It was very important to me to protect her.”
Kashiwada moved in with her parents. Her mother took time off to take care of her.
Kashiwada’s two young children, who were 3 and 6 at the time, stayed with their father so she could focus on her recovery.
“The kids would come home after school,” she says. “My dad would pick them up and take them to see me almost every day while their dad was at work.”
It took Kashiwada months to recover from the radiation treatments. She returned to work but her doctor advised her to avoid lifting heavy objects.
Kashiwada underwent his final reconstructive surgery a few weeks before COVID Lockdowns began in 2020. But his treatment was not over.
Her doctors told her that estrogen was fueling her cancer, so they prescribed medication to push her through early menopause. The treatment wasn’t as effective as they’d hoped. Her doctor performed surgery in 2021 to remove her ovaries.
More recently, she was diagnosed with osteopenia and will begin injections to stop bone loss.
Kashiwada said she has overcome many of the negative emotions she felt about her disease and wants other young women, including Asian American women like her, to be aware of their increased risk.
“No matter how healthy you are, whether you exercise or whatever you do, eating healthy, which I did, I would say it doesn’t make you invincible or immune,” she said. “I’m not saying you have to be afraid of everything, but you just have to be very in tune with your body and what it’s telling you.”
Phillip Reese is a data reporting specialist and associate professor of journalism at California State University, Sacramento.
This article was produced by KFF Health Newsa national newsroom that produces in-depth journalism on health issues and is one of the main operational programs of KFF — the independent source for health policy research, polling and journalism. KFF Health News is the publisher of California Medical Helplinean independent editorial service of California Health Care Foundation.
