Abstract
Background
Asian American Native Hawaiian Pacific Islander (AANHPI) patients are generally studied together despite diverse social, cultural, and economic backgrounds. We investigated survival disparities in disaggregated AANHPI lung cancer patients.
Methods
This retrospective cohort study identified 1,093,916 White, African American, and AANHPI non-small cell lung cancer (NSCLC) patients from the National Cancer Database (2010-2019). AANHPI subgroups included Chinese, Japanese, Filipino, Korean, Vietnamese, Indian, and “other.” Multivariate analyses assessed disparities in stage at presentation, time to surgery, and survival.
Results
Aggregate data demonstrated AANHPI patients have superior survival than Whites and African Americans (median survival 31.8 vs 19.2 vs 16.2 months, respectively). Disaggregation revealed disparities: Chinese patients have the best outcomes (46.2 months) while Japanese patients have the worst (17.7 months) with a 68% higher mortality risk than Whites (HR 1.68). Filipino patients demonstrated a 27% increased likelihood of stage IV presentation (HR 1.27), a 50% higher surgical delay risk (HR 1.50), and a 33% increased mortality risk (HR 1.33). Vietnamese patients have similar stage IV presentation and surgical delay risks, reducing survival. Of the AANHPI subgroups, Chinese patients had the best survival.
Discussion
While AANHPI patients generally demonstrate better survival than Whites and African Americans, heterogeneity exists within AANHPI subgroups. Chinese patients experienced the best outcomes, while Japanese, Filipino, and Vietnamese patients faced poor survival due to increased risk of late diagnosis and surgical delay. This underscores the importance of disaggregating AANHPI populations in cancer outcomes research and the need for culturally tailored strategies to improve screening, timely treatment, and survival.
Key Takeaways
• Significant disparities exist in lung cancer outcomes among disaggregated AANHPI subgroups. • Specific populations such as Japanese, Filipino, and Vietnamese patients are at increased risk of advanced stage presentation, delayed oncologic resection, and overall mortality.
Introduction
Lung cancer is the third most common cancer in the United States following breast cancer in females and prostate cancer in males. 1 Lung cancer is the leading cause of cancer-related mortality in the United States especially in the Asian American, Native Hawaiian, and Pacific Islander (AANHPI) population. 2 There are significant racial disparities that characterize lung cancer in the United States. African Americans, in particular, are diagnosed with lung cancer at a greater rate than Caucasians. African Americans are also more likely to be diagnosed with advanced stages of lung cancer. AANHPI patients receive fewer resections for early-stage lung cancer than other patient populations.3,4 In addition to race, socioeconomic factors including insurance status, have been found to impact overall survival. In a study using the Surveillance, Epidemiology, and End Results database, AANHPI patients without insurance or with Medicaid were more likely to present with advanced stage disease and have a decreased overall survival compared to their Caucasian counterparts.9,11
The AANHPI population is the fastest growing ethnic group in the United States. By 2040, 35 million AANHPI are projected to be living in the US and expected to double by 2060.5,6 This community is a heterogeneous group, encompassing people from more than 30 different countries. 7 However, most scientific literature tends to study AANHPI in aggregate despite significant variations in social, cultural, and economic backgrounds. 8
Several studies have identified differences in lung cancer incidence and screening patterns between disaggregated AANHPI subgroups, but little is known about survival and treatment patterns.4,8,9 Through analysis of the National Cancer Database (NCDB), we aim to provide a comprehensive characterization of lung cancer among Asian American, Native Hawaiian, and Pacific Islander (AANHPI) individuals. Our objective was to assess disparities in stage at diagnosis, time to surgical intervention, and overall survival. We hypothesized that disaggregating data by AANHPI subpopulations would reveal significant disparities that are otherwise obscured in aggregated analysis.
Methods
Data and Study Design
This is a retrospective cohort study using data from the National Cancer Database (NCDB) that describes survival outcomes among aggregated and disaggregated AANHPI patients diagnosed with non-small cell lung cancer (NSCLC). This study was exempt from IRB approval since the NCDB was used. The NCDB compiles de-identified patient data throughout the United States and accounts for approximately ∼70% of all cases diagnosed in the country.
10
Study eligible patients included White Caucasian (WC), African American (AA), and AANHPI patients with newly diagnosed non-small cell lung cancer (NSCLC) between 2010-2019. Those with missing survival status were excluded. AANHPI populations that were accounted for in the NCDB included Chinese, Japanese, Filipino, Korean, Vietnamese, and Indian NSCLC patients. While several other AANHPI ethnicities were disaggregated, we included them in our study as “other” if their population made up less than 1% of the study population. AANHPI subpopulations were analyzed in disaggregation among other comparison groups including WC and AA. The diagram in Figure 1 represents inclusion criteria defining the final cohort with 1,093,916 eligible patients. Selection of NSCLC patient cohort from the NCDB between 2010-2019
Study Variables
The study collected several patient characteristics, including age at diagnosis (years), gender, insurance status (private, Medicaid/other government insurance, Medicare, uninsured), median income (categorized as ≤$30,000, $30,000-35,999, $36,000-45,999, ≥$46,000), education level (percentage of patients without a high school diploma, categorized as ≥21%, 13-20.9%, 7-12.9%, <7%). Clinical demographics included facility type (community cancer program, academic program, integrated network cancer program), hospital setting (urban, rural, local), and distance from hospital (miles). Charlson-Deyo comorbidity score was used to evaluate patient comorbidities. Tumor histology, grade, lymph node status, treatment modality, and time to surgery were also considered. The primary dependent variable of interest was overall survival, which was accounted for in months. Secondary variables of interest included stage of presentation and time to surgery. The American Joint Committee on Cancer (AJCC) staging system was used to describe NSCLC stage of presentation. Time to surgery was accounted for in days, where treatment delay was defined as more than 60 days following initial diagnosis.
Statistical Analysis
Descriptive statistics were expressed as number (%), mean (SD), or median (first quartile, third quartile). Logistic regression models were used to determine median survival in disaggregated AANHPI patients presenting with NSCLC. Median survival and mortality risk (95% CI) was adjusted for age, sex, distance to treatment facility, facility type, insurance, income, Charlson-Deyo comorbidity, AJCC stage, grade, and treatment modality. The best-fitted model was chosen using Akaike Information Criteria (AIC). All analyses were performed using SAS Access Version 9.4 and R 4.2.2.
The distribution of variables was summarized separately by ethnicity as number (%), mean (SD), or median (first quartile, third quartile). Kaplan-Meier survival curves were used to estimate the median overall survival for the different ethnic groups. Survival models were used to compare the adjusted rates of death among the different ethnic groups and results presented as HRs (95% CI). Several survival models were assessed using Akaike’s information criteria (AIC), from which the flexible parametric survival models were used to quantify the relative risk of overall deaths between ethnicities. These models were adjusted for age, sex, location distance, facility type, insurance, income, medical comorbidities, treatment type, stage, and grade. Ordinal logistic regression models were used to compare the adjusted likelihood of delaying treatments or having severe cancer between ethnicities and results presented as ORs (95% CI). All analyses were done using SAS 9.4 (SAS Institute, Inc., Cary, NC) and R 4.2.2 and conclusions made at 5% significance.
Results
Patient Population and Baseline Characteristics
1,093,916 met inclusion criteria in our cohort. The majority were WC (n = 941,673, 86%), followed by AA (n = 123,779, 11%) and AANHPI (n = 28,464, 3%). In the AANHPI group, there were 7117 (25.0%) Chinese, 1897 (6.66%) Japanese, 4291 (15.1%) Filipino, 1997 (7.02%) Korean, 3172 (11.1%) Vietnamese, 2859 (10.0%) Indian, and 7131 (25.1%) other AANHPI patients. Average median follow-up time across all racial groups was 28.9 months. African American (AA) patients had the shortest follow-up time at 24.8 months, while Chinese patients had the longest at 32.6 months. Overall, Asian American and Native Hawaiian/Pacific Islander (AANHPI) patients experienced longer follow-up durations compared to White Caucasian (WC) patients, with median times of 29.9 months and 27.1 months, respectively.
Baseline Demographics of Patients With Non-Small Cell Lung Cancer (NSCLC) Stratified by Race
Cancer Severity at Presentation
AANHPI patients had a lower comorbidity burden compared to White and African American patients, with 75% presenting with Charlson-Deyo scores of 0 compared to 66% in both other groups. Among subgroups, Chinese (78%), Vietnamese (76%), and Filipino (70%) patients had the lowest comorbidity burdens.
Tumor grade distributions varied, with poorly differentiated tumors observed in 18% of AANHPI patients compared to 24% of both White and African American patients. Within AANHPI, Japanese (21%), Korean (21%), and Filipino (20%) patients had the highest rates of poorly differentiated tumors.
Stage at presentation differed significantly (Figure 2A). 49% of AANHPI patients presented with stage IV disease compared to 38% of White and 44% of African American patients. Vietnamese and Filipino patients had the highest proportions of late-stage disease, with 54% and 52%, respectively, presenting with stage IV. Chinese patients had the highest proportion of early-stage disease, with 27% diagnosed at stage I, similar to the rate among White patients (Table 1). On multivariate analysis, Filipino patients had a 27% increased risk of presenting with stage IV disease (HR 1.27, 95% CI 1.13-1.43, P < 0.01), and Vietnamese patients had a 37% increased risk (HR 1.37, 95% CI 1.18-1.57, P < 0.01), while Chinese and Indian patients did not have an increased risk (Table 2). Adjusted odds ratio for (A) stage of presentation, (B) time to surgery, (C) mortality, (D) mortality among AANHPI only Clinical Characteristics of Patients With NSCLC Stratified by Race
Treatment Delays
Treatment delays, defined as more than 60 days from diagnosis to surgery, were most common among Filipino and Vietnamese patients (Figure 2B). Compared to White patients, Filipinos had a 50% higher risk of surgical delay (HR 1.50, 95% CI 1.35-1.67, P < 0.001), and Vietnamese patients had a 36% higher risk (HR 1.36, 95% CI 1.20-1.55, P < 0.001). African American patients also experienced higher rates of delay (HR 1.25, 95% CI 1.22-1.28, P < 0.001). Japanese patients had a modestly increased risk (HR 1.15, 95% CI 1.01-1.31, P = 0.04), while Chinese, Indian, and Korean patients did not demonstrate significant differences from White patients.
Overall Survival
When considered in aggregate, AANHPI patients had the longest median survival at 31.8 months compared to 19.2 months for White patients and 16.2 months for African American patients (Figure 3A). However, disaggregation revealed striking differences (Figure 3B). Chinese patients had the longest survival at 46.2 months (IQR 42.8-49.1), while Japanese patients had the shortest at 17.7 months (IQR 16.0-19.6). Filipino and Vietnamese patients demonstrated intermediate survival outcomes but fared significantly worse than Chinese patients. Overall Survival for NSCLC Cohort: (A) White Caucasian, African American Population and Aggregated AANHPI. (B) Disaggregated AANHPI populations
Stage-specific analyses reinforced these findings. Figure 4 shows that Chinese patients consistently experienced superior survival across stages I through IV, while Japanese patients demonstrated the poorest survival outcomes across all stages. Filipino patients had reduced survival compared to Chinese patients, while Vietnamese patients were particularly disadvantaged due to their greater likelihood of presenting with late-stage disease. Overall Survival in Disaggregated AANHPI populations according to NSCLC Staging: (A) Stage 1, (B) Stage 2, (C) Stage 3, (D) Stage 4
Mortality Risk Analyses
Multivariate survival analyses further highlighted disparities in mortality risk. When the entire cohort was examined with White patients as the reference, most AANHPI subgroups demonstrated improved survival, including Chinese, Filipino, Korean, Vietnamese, Indian, and Other patients (Figure 2C). Chinese patients had the most favorable outcomes (HR 0.55, 95% CI 0.53-0.57, P < 0.001), while Japanese patients did not differ significantly from White patients (HR 0.99, 95% CI 0.94-1.05, P = 0.72) (Table 4).
When the analysis was restricted to AANHPI patients only, using Chinese patients as the reference group, striking disparities emerged (Figure 2D). Japanese patients had a 68% higher risk of death compared to Chinese patients (HR 1.68, 95% CI 1.57-1.79, P < 0.001). Filipino patients also experienced significantly worse survival, with a 33% higher mortality risk (HR 1.33, 95% CI 1.26-1.40, P < 0.001). Together, these findings underscore that while AANHPI patients as an aggregate appear to have superior survival compared to White patients, disaggregation reveals that Chinese patients disproportionately drive these favorable outcomes. Other subgroups, particularly Japanese and Filipino patients, face substantially worse survival when compared to other AANHPI subpopulations.
Discussion
As the AANHPI population in the United States is projected to double by 2060, understanding subgroup-specific disparities in lung cancer outcomes is critical. 6 Prior work has demonstrated heterogeneity in cancer incidence and survival across AANHPI subgroups in breast, colorectal, and pancreatic cancers,8,12,13 yet studies of lung cancer have largely focused on incidence and screening. Our analysis builds on this literature by examining stage at diagnosis, treatment delays, and survival outcomes in disaggregated AANHPI patients, which has never been previously reported.
We found that aggregate analyses mask important differences between patient subpopulations. Compared with White patients, most AANHPI groups—including Chinese, Filipino, Korean, Vietnamese, and Indian—appeared to have superior survival (Figure 3). However, when disaggregated with Chinese patients as the reference, Japanese and Filipino patients had significantly worse outcomes, with Japanese patients showing a 68% higher mortality risk (HR 1.68, 95% CI 1.57-1.79) and Filipino patients a 33% higher risk (HR 1.33, 95% CI 1.26-1.40). Vietnamese and Korean patients also demonstrated modestly higher mortality, while Chinese patients consistently had the most favorable outcomes (Figures 2-4, Table 4). These findings highlight how the survival advantage attributed to AANHPI populations is largely driven by Chinese patients, obscuring disparities within other subgroups.
Differences in stage at presentation and timeliness of surgery contributed to these disparities. Vietnamese and Filipino patients had the highest odds of presenting with stage IV disease (OR 1.37 and 1.27, respectively, Figure 2A) and were also most likely to experience surgical delays of more than 60 days (HR 1.36 and 1.50, Figure 2B). These findings align with prior studies documenting lower lung cancer screening completion among Filipino patients and higher risk of late-stage disease among Vietnamese women.14,15 In contrast, the poor survival observed in Japanese patients was not explained by stage or treatment delays.
Even after adjusting for age, comorbidities, and insurance status, Japanese patients remained at increased risk of death, suggesting that other genetic, environmental, or cultural factors may underlie their worse outcomes. Interestingly, Japan has earlier lung cancer screening guidelines in comparison to United States. Lung cancer screening is available for patients greater than age 40, and includes chest radiography, sputum cytologic testing, and low dose CT screening. The adoption of these screening guidelines has led to a significant decline in lung cancer mortality rates in Japan and may need to be considered in Japanese Americans in the Unites States. 16
Our study is limited by the retrospective design and the constraints of NCDB data, which lack information on smoking status, disease-free survival, and self-reported ethnicity. Cultural and socioeconomic barriers, such as language proficiency, immigration status, and access to culturally tailored care, could not be measured but likely contribute to subgroup disparities. Nonetheless, these findings reinforce the need to disaggregate AANHPI populations in outcomes research. While aggregate analyses suggest survival advantages, subgroup-level analyses reveal that Japanese, Filipino, and Vietnamese patients face disproportionately poor outcomes. Future work should focus on targeted screening strategies, reducing treatment delays, and culturally tailored interventions to improve survival among these vulnerable subgroups.
Footnotes
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.