Hidden in plain sight: By exploring diversity among Asian Americans, the DREAM Lab offers insights into cancer risks for all

Scarlett Gomez

This year the United States saw an alarming uptick in violence not just against Chinese Americans – wrongly blamed for the arrival of COVID-19 – but also against Taiwanese, Thai, Japanese, Filipino Americans and others perceived as having Asian heritage.

In its absurdity, the violence called attention to an unaddressed question about Asian American identity: Does it make sense to lump together Americans whose ancestors hail from every part of Asia? Most government and health data collection efforts list Asian American – and often Asian American/Pacific Islander – as a single ethnicity, forcing into a single check box those with ancestral roots in India or China, Taiwan or Hawaii, Tonga or Turkmenistan.

From a health standpoint, this wide Asian category risks concealing more than it reveals. That issue is the focus of a body of work coming from faculty members Iona Cheng, PhD, MPH, Scarlett Lin Gomez, PhD, MPH, and Salma Shariff-Marco, PhD, MPH, in the Disparities Research: Environment and -oMics (DREAM) Lab.

The three joined the Department of Epidemiology and Biostatistics together in 2017, coming as a group from the Cancer Prevention Institute of California. Cheng completed a postdoctoral fellowship in genetic epidemiology at UCSF under John Witte; Shariff-Marco trained as a social and behavioral scientist at Johns Hopkins. Since Gomez was a PhD student at Stanford, she has been working to identify the risk of cancer and cancer mortality in Asian Americans from diverse countries of ethnic origin.

Gomez traces this interest to family experiences. When her grandmother fell ill with a gastrointestinal cancer, Gomez reflected on how much of her family history – where they lived, where they worked – was determined for them, as one of just a handful of Asian immigrant families in predominantly white parts of Washington State. Gomez was particularly surprised to learn that the relatives who helped her grandmother through cancer treatment never actually told her what her diagnosis was. Gomez points to a common cultural observation that Asians often shy away from talking about illness or other personal struggles.

Multiplied across the community, that meant that the effects of all the common risks in immigrant communities – dry cleaning chemicals, to consider an obvious example – had invisible impacts. Asian Americans would be put at further disadvantage if they couldn’t share with their doctors their full family medical histories because they didn’t know them.

And public data sources had their own version of this silence. “No data means no disparities,” Gomez said wryly.

Gomez was also motivated by a story told by the co-founder of the Asian and Pacific Islander National Cancer Survivors Network, Susan Shinagawa. When Shinagawa first told her doctor she’d felt a lump, the doctor responded, “Asian women don’t get breast cancer, and you’re too young anyway.”

But Asian and Asian American women do get breast cancer. The cancer has been on the rise in Asia and among Asian American women. And Gomez found that U.S.-born Chinese and Filipina women have higher rates of cancer than white women of the same age until they reach around age 50, when white women’s risk increases and exceeds theirs. Their risk-over-time trendlines look different, a discovery that was interesting enough to generate press interest in one of Gomez’s early journal articles.

More recent papers have identified elevated cancer risks for a number of common cancers among particular Asian ethnicities. They found, for instance, that among Asian American and Pacific Islander women diagnosed with lung cancer, more than four out of five of the Indian and Chinese American women have never smoked. Those findings led to an additional study to look for genetic and cultural risk factors.

What determines the differences in cancer risks and outcomes in different Asian ethnicities? Genetics may play a part, but other common factors also demand attention. Socio-economic inequities create health inequities across all ethnic groups. In Asian communities, there’s the added distinction between those who immigrated recently and those who have been in the U.S. for all or most of their lives. New immigrants may have been exposed to distinct toxins before they came to the United States. Their health behaviors – what they eat, if they smoke – initially reflect their culture of origin.

This is where Shariff-Marco’s expertise comes into play. From her early days as a social scientist, she saw cancer epidemiology as a vantage onto how public health can best serve diverse communities.

"I thought I was going to learn about intervention research and then get back out there designing and evaluating interventions,” she explained. “But as I got thinking more about understanding the social determinants of health, I realized this research could inform that work,” she said of her move from social science into epidemiology.

The two saw an opportunity to study external cancer risk factors by looking at neighborhoods, which would reveal the shared risks Gomez had pondered early on. The DREAM Lab has focused on neighborhoods to address the interplay of race/ethnicity and other social determinants of health. As the tools for spatial modeling have become more robust in recent years, the team has developed new methods to analyze cancer data in areas smaller than counties, which is hard to do without risking violating patients’ privacy.

Iona Cheng’s shared interest in neighborhood environments and cancer risk– specifically the effect of neighborhood health factors related to food on breast cancer survival – that connected her with Gomez and Shariff-Marco in 2013. The group found that the effect of neighborhood factors on obesity and breast cancer mortality “differed across racial/ethnic groups,” but with no association seen in Asian Americans. The results of further research suggest that the problem was the diversity among Asian American cultures and neighborhoods.

For instance, in a recent study, Cheng, Gomez and Shariff-Marco, with others, compared cancer outcomes in affluent and disadvantaged Asian American enclaves and found that living in a poorer Asian ethnic enclave was associated with better outcomes, whereas living in a richer Asian enclave was associated with worse outcomes. Cheng hypothesizes that there are more Asian-focused resources available in poorer neighborhoods.

As a frequent collaborator and co-lead of the lung cancer research, Cheng applies her expertise in genetic and molecular epidemiology to “integrate biology, behavioral, and neighborhood factors” to look for the mechanisms that turn external risk factors into cancer.