Ethnic and racial differences in gastric cancer incidence in the US – 2022 Gastric Cancer Summit

[00:00] Our next speaker I happened to notice was on your white paper, so it's great to see an epidemiologist on that white important paper that you've put together. Yoonjin Lee is a professor at University of Southern California. She did her earlier training in Korea and then at Seoul National University, I believe, and then went to

[00:20] USC for her PhD and she'll be talking to us today about ethnic and racial differences and gastric cancer incidence in the US. Thank you very much. So thank you and it's great to be here just after the pandemic is my first trip it's great to see so many of you

[00:40] interest in gastric cancer is unusual. So I'm going to talk about ethnic ratio differences and gastric cancer incidence in the US. Again, while we are waiting, I am an epidemiologist. I work at USC. The other had my my work is doing a research in breast cancer.

[01:00] cancer and chemicals, and I also wear a hat as an epidemiologist for cancer registry in LA County. So, official name of cancer registry in LA County is LA County Cancer Surveillance Program. And I work with Dr. Daniel Stipan, who is not here. He was here

[01:20] two years ago, in the meantime, he retired, is enjoying his relaxed life. So that's something I am prepared to talk about, and that's I think pretty much it that I can say without the slides. Okay.

[01:40] Okay, so one more thing is, gastric cancer is not in the top 10 cancer sites in the US. It is number 12 for men and number 16 in women, as Sheehy just said. The next slide I was going to show was the...

[02:00] significantly high rate in the US in the 1930s. So in the 1930s, gastric cancer was the leading cause of cancer death and then it declined dramatically over time into the 1970s and then it continued to decline after that.

[02:20] Then I was going to show you more recent instance trends in the US. Thank you. Using the CR data between 2000 and 2019. So for those of you who are not familiar to us, CR is it's surveillance, epidemiology, and end results.

[02:40] CR is an NCI program providing collective data from selected population-based cancer registries across the states. And CR has been expanding over time and now it has 22.

[03:00] registries, it has 22 registries covering about half of the U.S. population. Go back. Thank you. So the rate has been

[03:20] decreasing across all racial ethnic groups in the US between 2000 and 2019. And what we can see here is a remarkable disparity across racial ethnic groups. So for all minority groups, the green is an Alaska

[03:40] American Indian and Alaskan Native, then non-Hispanic black and API, Asian Pacific Islanders, and Hispanic populations all have about twice higher instance than non-Hispanic whites, both for men and women. About the API, it is now better recognized that

[04:00] that API or Asian subgroups or heterogeneous group and disaggregating API or Asian subgroups could reveal some hidden health disparities. Next. And Asian American populations have grown substantially over time. And just between 2,000 and 1,000

[04:20] In 2019, the number has doubled. And with this increasing number, we are now better positioned to provide a subgroup-specific disaggregated data. Next. In fact, in LA County, where we have a large Asian population,

[04:40] We have been disaggregating API or agent subgroups and reporting the subgroup specific instance since 1976. So now we can see remarkable and enormous disparities for certain subgroups.

[05:00] The Korean Americans have the highest incidence and Japanese shown in purple have the second highest together with Vietnamese shown in green. And then non-Latino whites at the bottom have the lowest rate together with Filipino

[05:20] and South Asians. And in the middle there are a number of minority groups including African American, Chinese, Hispanics, and Southeast Asians. Still these groups also have nearly two-fold higher instance than non-Hispanic whites. A similar

[05:40] parent of instance disparities observed for women. Next. I just want to point out that the recent rates in Koreans towards the right part of the graph is similar to the rates in U.S. whites in the 1970s.

[06:00] 1940s and recent rates in the group there, including African-American, Hispanic, and Chinese, the Southeast Asians, that's similar to the rates in whites in the 1970s. Next.

[06:20] Worldwide, oh, worldwide, Korea and in Japan have been reporting the highest instance. So we wanted to look at the instance trends in Korean Americans and Japanese Americans. The two groups that have the highest rate in

[06:40] the US, this time using the data from California. It's a statewide data available since 1988. Next. So as in LA, Korean Americans have the highest instance about five times that next the non-Hispanic whites. Next.

[07:00] And about half when compared to the data from South Korea. Next. Now adding the data on Japanese, the top, the South Korea and Japan have the highest instance worldwide. The middle and the black, that's Japanese American rate.

[07:20] They have the second highest incidence in California, but there is a big gap between Korean and Japanese Americans in California. So Japanese Americans' rates are closer to the rate in non-Hispanic whites than to the rate in native Japanese. Next.

[07:40] So the similar instance pattern is observed for women. Can you go back? Can you go back one? Thank you. So the difference between Korean American and Japanese American is that it's not a matter of women. It's not a matter of women. It's not a matter of women. It's not a matter of women. It's not a matter of women. It's not a matter of women. It's not a matter of women.

[08:00] American instance trends can be attributed to the difference in their immigration history. So Japanese Americans have much longer immigration history. So 70% of them are US-born, second, third, or fourth generation immigrants. But the vast majority of Koreans, up to 70%

[08:20] were born in Korea. And we know that Asian immigrants experience significant changes in lifestyle and cancer incidence patterns after migration. Yeah. Next.

[08:40] So, we wanted to look at the instance patterns by nativity or by country birth. This is California data. The blues are men and the yellows are women.

[09:00] So here we can see that the instance in U.S. born Japanese Americans are very low, is close to the rate in non-Hispanic whites. But the rates in foreign born Japanese is much, much higher. It's almost the same as the rate in foreign born Korean Americans.

[09:20] So especially for men. Next. So here we are adding the data for other immigrant populations. Some US-born populations, the data are hidden because the numbers are so small we have to suppress.

[09:40] Next. So a few notable findings are that for Chinese-American men and women, their instance is, sorry, foreign-born Chinese-American men and women, their instance is higher than the instance in non-Spanish-American men.

[10:00] men and women respectively. Next. But for US-born Chinese Americans, the incidence is pretty low. Next. For Filipino Americans, the incidence was low regardless of nativity. Next. And for

[10:20] For Hispanics, the difference between US-born and foreign-born populations was relatively small. And the instance in US-born, next, Hispanic men and women were higher than the rates in non-Hispanic white.

[10:40] men and women respectively again. Next, sorry, sorry, go back. So the overall conclusion from this sub-negativity specific analysis is that generally foreign-born immigrant populations are at much much higher risk.

[11:00] compared to their US-born counterparts. So we have some data coming from the real data that will supplement the imaging results from the modeling. So next. With that, we are now looking at the stage distribution. So this graph shows the percentage of local

[11:20] localized stage, so as Sergio mentioned, it's a registry term of all the stage diagnosis. So what it shows is percentage of localized stage disease out of all stomach cancer patients.

[11:40] In 2019, as we can see here, the red line that's for Korean Americans, the percentage of localized disease is higher in Korean Americans than all other race ethnic groups, consistently through

[12:00] out the time period. And for some of you who were here two years ago, you may recall that we said the gap between Korean Americans and all others were widening. And this time, the data from the most recent time frame, the percentage for Korean Americans

[12:20] actually declined. We are not sure if this is just one type of fluctuation or may persist in the future. But regardless, it is clear that Korean Americans are diagnosed earlier than any other race ethnic groups. Next.

[12:40] data from Japan and Korea are much higher. So Japan about 56% around 2006. And in Korea 67% in 2019. So next. So the data is separated by a nativity.

[13:00] Next. Here we can see that foreign-born Korean Americans have the highest percentage of localized age diagnosis. In contrast, the percentage in foreign-born Japanese Americans was lowest. So this is puzzling finding.

[13:20] We do not have an explanation for that. Next. So now we are looking at the percentage or stage distribution among Korean Americans across the state.

[13:40] states using the SIR data. As we can see here, the percentage of localized stage diagnosis among Korean-Americans was higher in LA County than in other areas in California or outside of California.

[14:00] So 49, 41, and 36%. Next. But for other race ethnic groups, this was not true. So percentages were similar across the regions or even lower in LA county. Next.

[14:20] Again, all these percentages are much lower than that in South Korea, 66%, where there is a population-based screening program. And also, opportunistic endoscopy screening is widely available, as in Japan.

[14:40] Next. So what's different in LA County is that there is a large Korean American community. So that's the largest community outside of Korea. So many Korean patients in LA County have access to Korean American physicians. So they are,

[15:00] likely to be more aware and more open to all the use of endoscopy. And there was community-driven efforts to increase awareness among physicians and patients early on. So we—next.

[15:20] We believe the more aggressive use of endoscopy led to all of your diagnosis in Korean Americans. Again, this is lower than what's being done in Korea. And we believe it can be improved and it should be expanded.

[15:40] to other racial ethnic groups, particularly the foreign-born Japanese Americans. Next, next. So expected from the stage of distribution, the five year survival rate in California is high.

[16:00] highest among Korean Americans, that's 44%. Next. And looking at the same survival rate among Korean Americans across the Sierra region, we see that survival is higher in LA County than other areas of California, or other areas.

[16:20] outside of California. Next. Again this is much lower than the survival rate in native Koreans. Next. So this is my last slide and it shows the time trends of death rate due to stomach pain.

[16:40] cancer by a race ethnicity in California. Even though Korean Americans are diagnosed with ulcer, they have the highest mortality rate due to the high incidence. And there's a 5-4 difference between Korean Americans and non-Hispanic whites. And for

[17:00] for the other minority groups, it doesn't look that different in this graph, but their mortality rate is still more than twice than the mortality rate in non-Hispanic whites. Next. So in summary, stomach cancer is not

[17:20] common in the US, but there are high risk race ethnic groups. Foreign-born immigrant populations experience substantial disparities. Korean Americans are diagnosed all they are, likely due to all their use of endoscopy. And as we'll learn later

[17:40] long cancer screening for asymptotic high risk populations with heavy smoking history could provide an example for targeted screening. So we hope that we could consider an offer insurance coverage for endoscopy screening for high risk populations.

[18:00] Next. So my acknowledgments to my colleagues at USC and Cancer Registry in L.A. County. So again, Dennis was here two years ago. He has been the strong supporter of our gastric cancer work in L.A. County Cancer Surrelation Program. Thank you.

[18:20] Applause