A 20-year study involving 215,000 participants recruited from Los Angeles County and Hawaii uncovers under recognized health disparities.

Native Hawaiians are at highest risk for pancreatic cancer, according to a Keck School of Medicine of USC study that provides a surprising look at disparities surrounding the deadly disease.

The findings — published in the journal Cancer Medicine — could help focus efforts to prevent pancreatic cancer, which will kill an estimated 45,750 people in the United States this year.

The study shows:

• Native Hawaiians have a 60% increased risk for pancreatic cancer, compared to European Americans.
• Japanese Americans have a 33% increased risk for pancreatic cancer, compared to European Americans.
• African Americans have a 20% increased risk for pancreatic cancer, compared to European Americans.

“The greater risks in Native Hawaiians and Japanese Americans, compared to whites — in addition to the already reported increased risk in African Americans — are new, important findings,” says senior author Veronica Wendy Setiawan, PhD, associate professor of preventive medicine at the Keck School. “This study underscores the importance of studying diverse populations in cancer research.”

More than 20 years of data

For the research, scientists turned to the Multiethnic Cohort Study, established in 1993-1996 by USC and the University of Hawaii to investigate patterns in cancer incidence. The study includes more than 215,000 people recruited from Los Angeles County and Hawaii. The main ethnic groups represented are European American, African American, Latino American, Japanese American and Native Hawaiian.

Participants completed self-administered questionnaires, which included information on demographics, medical conditions, family history of cancer and lifestyle factors. Individuals were excluded if they had a prior pancreatic cancer diagnosis or were missing information integral to the study.

The resulting group numbered 184,559 individuals: 100,969 females and 83,590 males. The largest racial/ethnic group was Japanese Americans (29%), followed by European Americans (25.1%), Latino Americans (22%), African Americans (16.7%) and Native Hawaiians (7.3%).

There were 1,532 cases of pancreatic cancer over an average follow-up period of 16.9 years. The researchers took into account family history of pancreatic cancer, diabetes, smoking, body mass index, alcohol and red meat consumption. They said 20% of the cases could be attributed to smoking, obesity and red meat intake.

The study doesn’t answer why certain groups are more at risk but it did make a number of observations about risk factors, including:

• Family history of pancreatic cancer was slightly more prevalent in Japanese Americans.
• Native Hawaiians and African Americans were more likely to be current smokers.
• Diabetes mellitus was more common in African Americans, Latino Americans and Native Hawaiians.
• Red meat intake was highest among African Americans, Latino Americans and Native Hawaiians.

Disparities not limited to one group

“Our results show that African Americans are not the only minority populations with increased risk of pancreatic cancer,” Setiawan says. She added that Latinos and whites are at similar risk. Approximately 56,770 people — roughly 12.9 per 100,000 people — will be diagnosed with pancreatic cancer in the United States in 2019, according to the National Cancer Institute. There are no symptoms in the early stages; it is often detected late and has a poor prognosis.

by Leigh Hopper

The work was supported by grants from the National Cancer Institute (RO1CA209798, T32CA009142 and UO1CA164973) and the American Cancer Society (RSG-16–250-01- CPHPS).