Breast cancer among AAPI women is increasing

Christina Kashiwada was traveling for work in the summer of 2018 when she noticed a small, itchy lump in her left breast.

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At first, she didn't think much of it. She did routine self-exams and went to doctor's appointments. But a relative urged her to get a mammogram. She followed the advice and learned that she had stage 3 breast cancer – a discovery that shocked her.

“I'm 36 years old, right?” said Kashiwada, a civil engineer from Sacramento, Calif. “Nobody thinks about cancer.”

In 2021, about 11,000 Asian American 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 American and Pacific Islander women — a group that previously had relatively low diagnosis rates — is rising much faster than many other racial and ethnic groups. The trend is especially strong among young women like Kashiwada.

About 55 out of 100,000 Asian American and Pacific Islander women under age 50 were diagnosed with breast cancer in 2021. That's higher than for Black and Hispanic women and on par with the rate for white women, according to age-adjusted data from the National Institutes of Health. (Hispanic people can be of any race or a 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% from 2000 to 2021. The rate for AAPI women ages 50 to 64 increased by 33% during that period, and the rate for AAPI women ages 65 and older increased by 43%. By comparison, the rate for women of all ages, races, and ethnicities increased by 3%.

Researchers have recognized this trend and are now trying to figure out why it occurs in this ethnically diverse group. They suspect the answer is complex, ranging from cultural changes to stressful lifestyles – but they acknowledge it remains a mystery and is difficult for patients and their families to discuss due to cultural differences.

Helen Chew, director of the Clinical Breast Cancer Program at UC Davis Health, said the Asian American diaspora is so large and diverse that there are no simple explanations for the rise in breast cancer.

“This is a real trend,” Chew said, adding, “It's just difficult to figure out the exact reasons behind it. Is it because we're seeing an influx of people who have less access to healthcare? Is it because of a lot of cultural factors that make them not want to go to the doctor when they see something on their breast?”

This puzzle needs to be solved urgently because it costs lives. While breast cancer death rates are declining sharply among women in most ethnic and racial groups, about 12 out of 100,000 Asian American and Pacific Islander women of all ages will die of breast cancer in 2023. This is essentially the same death rate as in 2000, according to age-adjusted, preliminary data from the Centers for Disease Control and Prevention. The breast cancer death rate among all women fell by 30% during that period.

The CDC does not list breast cancer death rates for many different groups of Asian American women, such as women of Chinese or Korean descent. However, it has begun to distinguish between Asian American women and Pacific Islander women.

From 2018 to 2023, nearly 9,000 Asian American women died of breast cancer, compared to about 500 Native Hawaiian and Pacific Islander women. However, the breast cancer death rate during this period was 116% higher among Native Hawaiian and Pacific Islander women than among Asian American women.

The rates of pancreatic cancer, thyroid cancer, colon cancer and uterine cancer, as well as the rates of non-Hodgkin lymphoma, have also recently increased significantly among Asian American and Pacific Islander women under 50, NIH data show. Yet breast cancer is much more common among young AAPI women than any other cancer—especially concerning because young women are more likely to suffer from 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. “In Asian/Pacific women under 50, we're seeing an increase of even more than 4% per year.”

Gomez is lead researcher on a large study examining the causes of cancer in Asian Americans. She said there isn't enough research yet to know what's causing the recent increase in breast cancers. The answer may involve multiple risk factors over a long period of time.

“One of the hypotheses we're investigating is the role of stress,” she said. “We're asking all kinds of questions about different sources of stress and different coping styles across the life course.”

It's probably not just because more screenings are being done. “We looked at trends by stage of disease at diagnosis and see similar rates of increase across all stages of disease,” Gomez said.

Veronica Setiawan, a professor and epidemiologist at the University of Southern California's Keck School of Medicine, said the trend may be related to Asian immigrants adopting certain lifestyles that put them at higher risk. Setiawan is a breast cancer survivor and was diagnosed several years ago at age 49.

“Asian women, American women, they are becoming more and more Westernized, so that they are now having their puberty earlier – an earlier age at [the first menstrual cycle] is associated with an increased risk,” said Setiawan, who is working with Gomez on the cancer study. “Perhaps later birth, delaying pregnancy or not breastfeeding is associated with an increased risk of breast cancer.”

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 caused years of suffering for many patients.

Kashiwada underwent a mastectomy after her breast cancer diagnosis. 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 treatment.

During her treatments, Kashiwada kept her ordeal a secret from her grandmother, who raised her. Her grandmother never learned of the diagnosis. “I didn't want her to worry about me or put herself under stress,” Kashiwada said. “She probably just wouldn't sleep if she knew what was happening. It was very important to me to protect her.”

Kashiwada moved in with her parents. Her mother took time off work to help care for her.

Kashiwada's two young children, then ages three and six, stayed with their father so she could focus on her recovery.

“The kids would come over after school,” she said. “My dad would pick them up and bring them to me almost every day while their dad was at work.”

It took Kashiwada months to regain her strength after radiation treatment. She returned to work, but with her doctor's instructions to avoid lifting heavy objects.

Kashiwada underwent her last reconstructive surgery a few weeks before the Covid lockdowns began in 2020, but her treatment was not yet complete.

Her doctors had told her that estrogen was driving her cancer, so they gave her medication to shorten her menopause. The treatment wasn't as effective as hoped. Her doctor performed surgery to remove her ovaries in 2021.

She was recently diagnosed with osteopenia and will begin injections to stop the bone loss.

Kashiwada said she has overcome many of the negative feelings she had surrounding her illness and wants other young women, including Asian American women like her, to be aware of their increased risk.

“No matter how healthy you feel, how much exercise you do, or whatever you do, eat well, and those are all things I've done – I would say it doesn't make you invincible or immune,” she said. “That's not to say you should be afraid of everything, but just be very in tune with your body and what your body is telling you.”

Phillip Reese is a data reporting specialist and associate professor of journalism at California State University-Sacramento.

This article was created by KFF Health Newswhich published California Healthlinean editorially independent service of California Health Foundation. Additional support comes from the Asian American Journalists Association – Los Angeles through The Californian Foundation.

KFF Health News is a national newsroom that produces in-depth journalism on health issues and is one of the core programs of KFF — the independent source for health policy research, polls and journalism. This story also appeared on CBS NewsIt may be reissued free of charge.