ÌÇÐÄvlog

Asian American (24 million people) and Native Hawaiian and other Pacific Islander (1.7 million people) individuals represent 8% of the US population.¹ Cancer is the leading cause of death among many Asian American groups (Chinese, Filipino, Vietnamese, and Korean) and is the second leading cause of death among Native Hawaiian, Indian, and Japanese American people.¹ A growing body of research has focused on cancer among these very diverse groups, elucidating their unique and dynamic cancer risk factors, epidemiology, and access to care.^2,3

Zhu et al⁴ evaluated cancer-specific mortality (CSM) rates for Asian American, Native Hawaiian, and other Pacific Islander individuals from 1999 to 2020 using the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research database. They found that for these groups in aggregate, CSM rates decreased over the past 2 decades and that decreases were greater among men than among women. The CSM rates among women increased for cancers of the uterus and the brain and central nervous system but decreased for other cancer sites. Upon analysis by age, women aged 65 to 74 years experienced the greatest increase in mortality from uterine cancer. Among men, CSM rates decreased overall, with the greatest decreases in cancers of the stomach and lung. Decreases in CSM were greatest in cancers of the liver and lung among men aged 35 to 44 years; however, colorectal cancer mortality increased among men aged 45 to 54 years, and after a decrease from 2002 to 2012, prostate cancer increased among men aged 64 to 74 years (from 2012 to 2020). The authors found increased mortality for pancreatic cancer in the Midwest and for uterine cancer and liver cancer across all US census regions.

The study by Zhu et al⁴ highlights the need to further study and address the cancer burden among these rapidly growing populations.¹ Their work is nationally representative and may inform cancer policy. Their findings illustrate how cancer mortality has changed over time, reflecting changes in risk factors, screening rates, and timely and equitable access to quality cancer care.^2-4 The study is limited by the aggregation of diverse Asian American and Pacific Islander groups, who exhibit some of the widest disparities in social determinants of health across census groups,^1-3 a limitation inherent in the dataset that masks heterogeneity in cancer mortality.^1-3

Heterogeneity in cancer mortality is notable. The age-adjusted mortality rate for all cancer subsites is 142 per 100 000 for Native Hawaiian and Pacific Islander patients, 91 per 100 000 for Asian American patients, and 153 per 100 000 for White patients.¹ For uterine cancer, the age-adjusted mortality rate is 16 per 100 000 for Native Hawaiian and Pacific Islander patients compared with 5 per 100 000 for White patients and 3 per 100 000 for Asian American patients.¹ For breast cancer, 5-year relative survival is 94% for Japanese American and 93% for White and Chinese patients compared with 72% for Tongan, 73% for Chamorro and Guamanian, and 74% for Samoan patients.¹ For cancers of the lung and bronchus, 5-year relative survival is 37% for Thai, 36% for Chinese, 35% for Pakistani, and 29% for Indian patients compared with 25% for White, 18% for Samoan, 15% for Tongan, and 11% for Laotian patients.¹ Such heterogeneity in mortality may reflect differences across the continuum of disease leading up to mortality estimates.²

Considering the current study and in the context of such heterogeneity, what are the next steps? First, further disaggregated research is needed to examine the drivers of these temporal changes. Although CSM has decreased overall for Asian American, Native Hawaiian, and Pacific Islander patients, decreases in lung CSM may be driven by relatively better survival among Chinese and Indian patients (and perhaps to a lesser extent by the smaller Thai and Pakistani populations) but may not reflect the substantially lower survival among several Pacific Islander and Southeast Asian (eg, Laotian) groups.¹ Increases in uterine CSM may reflect the burden of disease among Native Hawaiian and Pacific Islander individuals, among whom focused studies and interventions are needed.^1,3 Further research could explore how cancer risk compares between immigrants and people in their countries of origin and how cancer risk changes across generations of immigrants.⁵ Parallels between immigrants and their countries of origin may inform targeted diagnostics, as exemplified by the high rate of gastric cancer among Korean American individuals reflecting epidemiology in Korea.^1,5 Such work may also elucidate how risk changes in the US context, as suggested by the increase in prostate and colorectal CSM among (aggregated) Asian American, Native Hawaiian, and Pacific Islander men.⁴

Second, disaggregated research must go beyond incidence and mortality and should examine disparities across the cancer continuum. Screening rates are, on average, lower among Asian American individuals; surveyed uptake of Papanicolaou testing within the past 3 years was 69% among Chinese American and 74% among Indian women compared with 84% among White women.¹ Among Filipino American individuals, 47% were up to date with colorectal cancer screening compared with 57% of White individuals.¹ Disparities exist in stage at presentation, with several groups, particularly Tongan (12% distant disease at presentation for patients with female breast cancer), Samoan (15% distant disease), and Laotian individuals (9% distant disease) being more likely to present with advanced disease than White individuals (6% distant disease).¹ Among patients with lung cancer, 43% of White and 50% of Chinese patients presented with metastatic disease compared with 67% of Laotian, 60% of Hmong, and 58% of Vietnamese and Pakistani patients, despite far lower rates, on average, of smoking among Asian American women (83%-98% never-smokers compared with 63% among White women).¹

Treatment disparities exist among patients with localized colon cancer; for example, Filipino, Chinese, Japanese, Korean, and Vietnamese patients were found to experience increased time to treatment.⁶ End-of-life care must not be overlooked.⁷ Receipt of early palliative care may be lower among women of Indian and Pakistani descent with metastatic breast cancer and among patients of Indian, Pakistani, Chinese, Vietnamese, and Thai descent with metastatic non–small-cell lung cancer.⁷ Further work must elucidate factors underlying these disparities, including socioeconomic status, educational attainment, health literacy, and language, as well as psychosocial, cultural, and spiritual and existential preferences across the continuum of cancer.⁷ Qualitative studies may play a particularly crucial role for subgroups whose smaller sample sizes limit statistical power in registry-based work.

Third, population-based cancer research must inform action. Clinical trials should encourage diversity in enrollment for subgroups less often represented; disaggregating Native Hawaiian, Pacific Islander, and Asian American populations is an important first step given these groups’ unique histories and social determinants of health.³ Subgroups among Asian American as well as Native Hawaiian and Pacific Islander people also should be disaggregated. In the realm of research, the National Cancer Institute–funded Asian American Prospective Research study led by population scientists at the University of California, San Francisco is an important development. Efforts must also leverage cultural humility at diagnosis and treatment. Programs such as the University of Hawai’i and University of Guam’s Pacific Island Partnership for Cancer Health Equity and the Memorial Sloan Kettering Cancer Center’s South Asian Health Initiative and Chinese American Cancer Care Access Program are encouraging. However, parallel efforts are needed to strengthen cancer care for diverse, minoritized groups particularly in settings where the need is greatest.

This study by Zhu et al⁴ is evidence for the hopeful benefits of advances in cancer care. The decrements in CSM from 1999 to 2020 may reflect not only advances in cancer diagnostics and treatment but also improved access to care for many patients. However, these advances are not equitably distributed.^1-3,5-7 Race and ethnicity are ultimately social constructs such that many of these differences across populations may reflect intricate social determinants of health. These factors must be studied and leveraged to improve equity across the cancer continuum from cancer risk and diagnosis to treatment and end of life.

Published: November 4, 2024. doi:10.1001/jamanetworkopen.2024.42419

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2024 Dee EC. ÌÇÐÄvlog Open.

Corresponding Author: Edward Christopher Dee, MD, Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065 (deee1@mskcc.org).

Conflict of Interest Disclosures: Dr Dee reported receiving a center support grant from the National Cancer Institute during the conduct of the study.

Additional Contributions: The author thanks Rohan Patel, MD (Case Western Reserve University, University Hospitals Seidman Cancer Center); Kaitlyn Lapen, MD (Memorial Sloan Kettering Cancer Center); and Nina Sanford, MD (University of Texas Southwestern), for insight and critical review of the manuscript. These individuals were not compensated for their contributions.