Introduction

Cancer survival rates across racial and ethnic groups in the United States have long been a subject of intense scrutiny and concern. Numerous studies have consistently revealed disparities in survival outcomes among different populations, with African Americans, Hispanics, and certain other minority groups often exhibiting lower survival rates compared to non-Hispanic Whites for various cancer types1,2,3,4,5,6,7. These disparities persist despite advancements in cancer screening, treatment, and management over the past two decades3.

While improved survival has been observed for several cancers, such as breast cancer, non-Hodgkin’s lymphoma (NHL), and multiple myeloma, the extent to which these gains have been equally distributed across racial and ethnic lines remains unclear8,9,10.

This study aims to provide a comprehensive analysis of trends in 5-year relative survival rates for major cancer sites, including breast, colorectal, prostate, lung, pancreatic cancers, NHL, acute leukemia (AL), and multiple myeloma, across racial/ethnic groups in the United States1. By comparing data from two distinct periods, 2002–2006 and 2015–2019, we seek to elucidate whether the advancements in cancer treatment and management have translated into equitable improvements in survival outcomes for all populations.

Lung cancer has historically been associated with poor prognosis. In 2013, lung cancer screening guidelines were introduced in the United States, significantly impacting early-stage prognosis through the implementation of low-dose computed tomography (LDCT) screening11. Our study, by analyzing two distinct periods—2002–2006 and 2015–2019—provides a unique opportunity to assess survival outcomes both before and after the introduction of these guidelines. While the 2002–2006 cohort includes data up to 2012, prior to the implementation of the guidelines, the 2015–2019 cohort captures survival outcomes post-guideline. This comparison allows us to evaluate the differences in lung cancer survival before and after the introduction of the screening guidelines, with a particular focus on the disparities across racial and ethnic groups.

The selection of cancer types encompasses a diverse range, from those with established screening and treatment options (breast, colorectal, prostate) to cancers with limited screening and poor prognosis even at early stages (lung, pancreatic)1. Additionally, the inclusion of hematological malignancies like NHL, AL, and multiple myeloma, where long-term survival is possible even with late-stage diagnosis, provides a comprehensive perspective on survival trends across various cancer types1.

The data analyzed in this study were collected and categorized according to the revised race/ethnicity reporting guidelines, which were implemented to improve the accuracy and clarity of cancer statistics. This update aligns our analysis with the most current standards, ensuring that the disparities identified are reflective of these refined categorizations11.

By examining the intricate patterns and trends in cancer survival across different racial and ethnic groups, this study aims to highlight areas where healthcare policies and strategies may need to be adapted to ensure equitable cancer care and treatment outcomes for all segments of the population. The findings from this analysis have the potential to inform targeted interventions and resource allocation, ultimately working towards reducing the persistent disparities in cancer survival rates.

Materials and methods

Data source

The data for this study were derived from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute, spanning a 20-year period from 2000 to 2020. The SEER 17 registries, which cover approximately 26.5% of the U.S. population based on the 2020 census, were utilized to ensure a comprehensive and representative dataset12. The study used de-identified data from the SEER database and was exempt from institutional review board approval.

Cancer sites and populations

The analysis focused on major cancer sites, including breast, colorectal, prostate, lung, pancreatic cancers, non-Hodgkin lymphoma (NHL), acute leukemia (AL), and multiple myeloma. Due to the infrequency of individual leukemia types, AL data were aggregated for analysis. The study examined racial disparities among White, Black, American Indian/Alaska Native (AI/AN), and Asian/Pacific Islander (API) populations, as well as ethnic disparities between Hispanic and Non-Hispanic groups1.

Exclusion criteria

Cases identified solely through autopsy or death certificates were excluded from the analysis to ensure data accuracy and reliability. Approximately 0.17–2.11% of patients were either classified into multiple racial/ethnic groups, lacked such information, or belonged to other unspecified groups. These patients were excluded from race/ethnicity-specific analyses to ensure data accuracy and reliability.

Survival calculations

Age-standardized relative survival rates were calculated to enable comparisons across different demographic groups and time periods. The International Cancer Survival Standard (ICSS) was used for age standardization, employing the SEERStat software. Relative survival (RS) rates were computed to compare the survival of cancer patients with the expected survival of the general population13,14,15. The Ederer II method and life tables from the Centers for Disease Control and Prevention (CDC) were utilized to generate expected survival rates for the general population16.

Period analysis

To provide the most recent survival estimates, the study employed period analysis instead of traditional cohort-based analysis. Period analysis focuses on the most recent survival experiences of patients, offering a more up-to-date representation of survival trends. For cases diagnosed between 2002 and 2015, direct calculations of 5-year RS rates were performed using the SEERStat software. For cases diagnosed between 2016 and 2019, period survival estimates were utilized due to the unavailability of complete 5-year follow-up data by 202017.

Statistical analysis

Patient counts, relative survival rates, standard errors, and associated p-values for trend analysis were extracted for each 5-year interval. The p-value threshold for statistical significance was set at 0.05. All analyses were conducted using Python 3.10.13 and SEERStat 3.8.2, incorporating custom macros for analyzing relative and period survival rates.

Results

Patient counts

Tables 1 and 2 provide detailed patient counts categorized by cancer type, race, and ethnicity. Across all subgroups, patient counts generally exceeded 100, except for acute leukemia among Non-Hispanic American Indian/Alaska Native individuals, where the count was relatively low. Across various cancer types, Non-Hispanic White patients consistently had the highest case counts, while Non-Hispanic American Indian/Alaska Native patients consistently had the lowest.

Table 1 Five-year relative survival (RS) for solid malignancies diagnosed in 2002–2006 and 2015–2019.
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Table 2 Five-year relative survival rates for common hematological malignancies diagnosed in 2002–2006 and 2015–2019.
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Breast cancer

From 2002 to 2019, significant improvements were observed in 5-year relative survival (RS) rates for breast cancer across all racial/ethnic groups. Overall, the rate increased by 1.5% points, rising from 88.7 to 90.2% (P < 1 × 10⁻5). Non-Hispanic Black patients experienced the largest gain, with rates rising from 77.6 to 82.8%, a 5.2% point increase. Non-Hispanic Whites saw an increase of 1.6% points (from 90.5 to 92.1%), Non-Hispanic Asians/Pacific Islanders had an increase of 1.1% points (from 89.0 to 90.1%), Non-Hispanic American Indians/Alaska Natives experienced a 3.0% point increase (from 84.2 to 87.2%), and Hispanics had a 1.5% point increase (from 86.2 to 87.7%). Non-Hispanic Black patients showed improvement but had lower survival rates compared to Non-Hispanic Whites.

Prostate cancer

Overall, 5-year RS rates for colorectal cancer showed a slight decline of 0.6% points, from 64.7 to 64.1% (P < 1 × 10⁻5). Non-Hispanic Whites experienced a 2.5% point decrease (99.1–96.6%), while the decline was smaller for Non-Hispanic Blacks (96.1–94.9%, 1.2% points). Non-Hispanic American Indians/Alaska Natives experienced a 7.7% point decrease (96.9–89.2%). Non-Hispanic Asians/Pacific Islanders saw a 3.5% point decline (96.6–93.1%), and Hispanics had a 2.7% point decrease (95.7–93.0%).

Colorectal cancer

The overall survival for colorectal cancer declined slightly (64.7–64.1%), with the most notable decrease seen among Non-Hispanic American Indian/Alaska Native individuals, where survival dropped by 6.2% points (66.3–60.1%). This sharp decline underscores the unique challenges faced by this population. Non-Hispanic Whites experienced a 0.7% point decrease (66.0–65.3%), while Non-Hispanic Blacks showed a 1.5% point increase (56.8–58.3%), which is notable given that survival rates declined for most other racial/ethnic groups during the same period. The disparity remains in the absolute survival percentages, with Non-Hispanic Blacks still having lower survival (58.3%) compared to Non-Hispanic Whites (65.3%). Non-Hispanic Asians/Pacific Islanders also saw a 1.5% point decrease (66.7–65.2%), while Hispanics had a 1.2% point increase (61.6–62.8%).

Pancreatic cancer

The survival rate for pancreatic cancer increased by 6.1% points, from 6.3 to 12.4% overall (P < 1 × 10⁻5). Among non-Hispanic Whites, survival rates rose from 6.3 to 12.5%, reflecting an improvement of 6.2% points (P < 1 × 10⁻5). Non-Hispanic Blacks experienced a rise in survival rates from 5.0 to 10.5%, an increase of 5.5% points (P < 1 × 10⁻5). Non-Hispanic Asians or Pacific Islanders showed an increase from 8.0 to 14.9%, a 6.9% point increase (P < 1 × 10⁻5). Hispanics (All Races) saw an enhancement in survival rates from 6.8 to 12.5%, an increase of 5.7% points (P < 1 × 10⁻5). However, non-Hispanic American Indians/Alaska Natives were the only group to exhibit a decline, with survival rates decreasing from 6.3 to 3.6%, a reduction of 2.7% points (P < 1 × 10⁻5).

Lung cancer

Substantial improvements were noted in 5-year RS rates for lung cancer from 2002 to 2019, with an overall increase of 8.6% points, rising from 16.1 to 24.7% (P < 1 × 10⁻5). Non-Hispanic Asians/Pacific Islanders had the largest gain of 11.0% points (17.6–28.6%), followed by Non-Hispanic Blacks (12.5–21.5%, 9.0% point increase), Non-Hispanic Whites (16.5–24.8%, 8.3% point increase), Hispanics (15.7–24.4%, 8.7% point increase), and Non-Hispanic American Indians/Alaska Natives (12.4–20.6%, 8.2% point increase).

Non-hodgkin lymphoma

From 2002 to 2019, 5-year relative survival rates for non-Hodgkin lymphoma (NHL) increased across all racial/ethnic groups, with an overall rise of 6.0% points, from 66.2 to 72.2% (P < 0.00001). While Non-Hispanic Blacks exhibited a observable improvement in survival rates from 57.6 to 66.9%, a 9.3% point gain (P < 0.00001), it is important to note that other groups also had lower survival rates. Non-Hispanic American Indian/Alaska Native (AI/AN) individuals showed only a modest increase of 0.4% points, from 63.7 to 64.1% (P = 0.215798). Non-Hispanic Asian or Pacific Islander (API) patients experienced a 5.0% point increase, from 60.8 to 65.8% (P < 0.00001). Additionally, Hispanics showed a 7.3% point increase, from 59.8 to 67.1% (P < 0.00001), with only a 0.2% difference compared to Non-Hispanic Whites (75.0%).

Multiple myeloma

Notable increases in 5-year RS rates for multiple myeloma were observed across all racial/ethnic groups from 2002 to 2006 to 2015–2019. Non-Hispanic Asians/Pacific Islanders saw the largest gain, with an 18.7% point increase (from 39.8 to 58.5%), followed closely by Non-Hispanic Blacks, who experienced an 18.2% point increase (from 41.0 to 59.2%). Improvements were also observed in Non-Hispanic Whites, with a 14.8% point increase (from 43.8 to 58.6%), and Hispanics, with a 16.7% point increase (from 38.9 to 55.6%). Non-Hispanic American Indians/Alaska Natives showed a comparatively modest increase of 8.3% points (from 42.1 to 50.4%).

Acute leukemia

Overall, 5-year RS rates for acute leukemia increased significantly by 8.6% points, from 17.9 to 26.5% (P < 1 × 10⁻5) between 2002 and 2019. Non-Hispanic Whites saw an increase from 18.1 to 27.6%, a 9.5% point increase, followed by Hispanics (17.4–25.5%, 8.1% point increase), Non-Hispanic Asians/Pacific Islanders (19.7–26.7%, 7.0% point increase), and Non-Hispanic Blacks (15.3–21.0%, 5.7% point increase). Data for Non-Hispanic American Indians/Alaska Natives was lacking from 2002 to 2006, but their 2015–2019 survival rate was 7.1%.

Discussion

Persistent racial and ethnic disparities in cancer survival: a multifaceted challenge

Our comprehensive analysis provides insights into an intricate landscape of survival disparities across various cancers between 2002 and 2006 and 2015–2019, highlighting persistent inequities among different racial and ethnic groups in the United States. Despite overall improvements in survival rates for most cancers, these advancements have not been uniformly experienced, underscoring an ongoing challenge in achieving healthcare equity2,7,18. In this discussion, we will systematically address the findings by cancer type, maintaining coherence with the structure of the Results section.

Breast and prostate cancer: contrasting trajectories

The improvement in breast cancer survival across all groups, including Non-Hispanic Black patients, was noted19. However, the persistently lower survival rates in this group compared to Non-Hispanic Whites highlight the need for continued efforts to bridge this gap20. In contrast, the decline in prostate cancer survival across all races, with Non-Hispanic American Indian/Alaska Native patients showing the most pronounced decrease21.

Colorectal cancer: emerging trends and enduring racial divides

Our investigation into colorectal cancer survival rates reveals a nuanced and complex picture. The marginal decline in overall survival from 2002 to 2006 to 2015–2019 deviates from global progress in disease management, potentially reflecting deficiencies in screening methodologies or treatment protocols employed nationwide22,23,24. Interestingly, this downward trend contrasts with the notable improvements among Non-Hispanic Black patients. However, a disparity persists when compared to Non-Hispanic White survival rates, highlighting an ongoing challenge in bridging racial divides in healthcare outcomes25. The overall decrease, along with these disparities, indicates the need to examine the healthcare system’s ability to address the needs of diverse racial and ethnic groups2.

Pancreatic cancer: a pressing concern for non-hispanic American Indian/Alaska native populations

Conversely, our pancreatic cancer findings reveal a more positive overall trend, with increased survival rates suggesting advancements in early detection and treatment approaches26. Despite overall improvements in pancreatic cancer survival, the significant decline among Non-Hispanic American Indian/Alaska Native populations remains a cause for concern27. This could involve broadening access to early detection, advancing treatment options, and concerted efforts to overcome systemic barriers to quality healthcare access for these communities28,29.

Lung cancer, NHL, and myeloma: advances and lingering disparities

The substantial improvements in lung cancer and non-Hodgkin lymphoma survival across all groups reflect treatment advancements30,31. Similarly, while notable increases in myeloma survival, especially for Non-Hispanic Asians/Pacific Islanders and Non-Hispanic Blacks, suggest effective treatment progress, disparities persist, requiring further investigation32. However, the lower survival rates for Non-Hispanic Blacks in NHL compared to other groups indicate a disparity demanding attention33.

Acute leukemia: a concerning trend

The increase in acute leukemia survival is a positive sign of treatment progress. However, the lack of sufficient data and lower survival for Non-Hispanic American Indian/Alaska Native patients in 2015–2019 point to a critical gap in understanding and effectively serving this population34.

Ongoing disparities amidst improvements in cancer survival

Despite notable improvements in cancer survival rates across some racial and ethnic groups35, disparities in outcomes remain a significant issue. While certain populations have made gains, these have not been sufficient to close the gap in survival rates, highlighting the ongoing challenge of addressing cancer health disparities36. Our analysis indicates that while survival rates for several cancers have improved, persistent disparities between racial and ethnic groups are evident37.

For example, Non-Hispanic Black women experienced a 5.2% point increase in breast cancer survival (77.6–82.8%), yet their survival rate remains 9.3% points lower than that of Non-Hispanic White women (90.5–92.1%). In non-Hodgkin lymphoma, Non-Hispanic Black patients saw a substantial 9.3% point increase (57.6–66.9%), but this still leaves a gap of 12% points compared to Non-Hispanic Whites (75.2–78.9%).

For colorectal cancer, survival for Non-Hispanic Black patients rose modestly by 1.5% points (56.8–58.3%), whereas Non-Hispanic American Indian/Alaska Native patients experienced a 6.2% point decline (66.3–60.1%), suggesting widening disparities for this group. The decrease in pancreatic cancer survival for Non-Hispanic American Indian/Alaska Native patients (6.3–3.6%) is troubling, especially when other racial/ethnic groups showed improvement, such as Non-Hispanic Whites (8.4–10.1%) and Non-Hispanic Blacks (5.1–5.7%).

Implications for healthcare policy and practice

While our analysis did not directly investigate the impact of socioeconomic status (SES), healthcare access, and quality of care on cancer survival disparities, it is essential to acknowledge their potential influence38. Numerous studies have demonstrated that these factors significantly contribute to the disparities observed in cancer outcomes39. For instance, existing research indicates that lower SES, limited access to advanced medical treatments, and variations in the quality of care received can exacerbate survival disparities among racial and ethnic groups40. Although our study focused on survival trends, the broader context of these social determinants should not be overlooked, as they likely play a critical role in shaping the disparities we identified41. This aligns with existing literature on the factors influencing cancer survival disparities35.

The disparities in cancer survival rates among racial and ethnic groups are likely influenced by social determinants of health (SDOH), such as socioeconomic status, geographic location, and healthcare access, which can delay diagnosis and limit treatment quality. Studies by Shavers and Brown (2002) and Raghavan (2007) emphasize that socioeconomic and healthcare access disparities significantly impact cancer treatment outcomes4,5. Recent research by Iyer HS et al. (2023) further highlights that neighborhood-level social environments may have a greater effect on survival rates than genetic ancestry42. These findings suggest that SDOH play a critical role in shaping cancer treatment outcomes, influencing healthcare access, treatment adherence, and social support. Future research should explore how SDOH, alongside medical interventions, contribute to the ongoing survival disparities.

These findings underscore the need for targeted interventions to reduce survival disparities36. Policy efforts should focus on equitable access to care43, addressing systemic barriers, and ensuring advancements in treatment are distributed across all racial and ethnic groups37. Tailored strategies in cancer treatment and management, along with expanded healthcare access, are crucial for improving outcomes for all populations3.

Future research and policy directions

Future research should aim to unravel the complex interplay of biological, environmental, socioeconomic, and healthcare system factors contributing to these disparities. Tailoring cancer treatment and management strategies to improve healthcare access is crucial for reducing disparities in health outcomes1,2,44.

Limitations

While our study provided an important update to the seminal work of Pulte et al. (2012), analyzing five-year survival rates across a broad spectrum of cancers and diverse racial/ethnic groups, it came with inherent limitations. Firstly, our methodological framework was deeply rooted in the qualitative approach of Pulte et al., reflecting a continuation rather than an evolution of analysis techniques1. Moreover, factors such as socioeconomic status, access to healthcare, genetic predispositions, and treatment differences might have played a role in these disparities. However, the scope of our study was constrained by the unavailability of certain variables, such as socioeconomic status, access to healthcare, and treatment differences, which could not be assessed. These factors, although crucial, were beyond the dataset used, highlighting the need for future research to explore their impact on survival disparities45,46,47,48,49. This limitation underscored the need for further research that delved deeper into these factors to fully comprehend and address the causes of survival disparities in cancer treatment outcomes. Additionally, future studies should focus on distinguishing between statistical and clinical significance to better interpret the real-world impact of these results.

Conclusion

Our analysis highlights progress in cancer survival over the past two decades while revealing ongoing disparities among racial and ethnic groups, particularly in pancreatic and colorectal cancers. The decline in pancreatic cancer survival for Non-Hispanic American Indian/Alaska Native individuals and the overall decrease in colorectal cancer survival were noted. These disparities indicate the importance of evaluating and potentially improving access to advanced cancer treatments and developing targeted approaches to effectively bridge gaps in survival rates across all populations.