Racial and ethnic disparities in gallbladder cancer: A two-decade analysis of incidence and mortality rates in the US.

BACKGROUND: Gallbladder cancer (GBC) is an aggressive malignancy that is usually diagnosed at a late stage. Prior data showed increasing incidence of GBC in the US. However, little is known about race/ethnic-specific incidence and mortality trends of GBC per stage at diagnosis. Therefore, we aimed to conduct a time-trend analysis of GBC incidence and mortality rates categorized by race/ethnicity and stage-at-diagnosis. METHODS: Age-adjusted GBC incidence and mortality rates were calculated using SEER*Stat software from the United States Cancer Statistics database (covers ~98% of US population between 2001 and 2020) and NCHS (covers ~100% of the US population between 2000 and 2020) databases, respectively. Race/Ethnic groups were Non-Hispanic-White (NHW), Non-Hispanic-Black (NHB), Hispanic, Non-Hispanic-Asian/Pacific-Islander (NHAPI), and Non-Hispanic-American-Indian/Alaska-Native (NHAIAN). Stage-at-diagnoses were all stages, early, regional, and distant stages. Joinpoint regression was used to generate time-trends [annual percentage change (APC) and average APC (AAPC)] with parametric estimations and a two-sided t-test (p-value cut-off 0.05). RESULTS: 76,873 patients were diagnosed with GBC with decreasing incidence rates in all races/ethnicities except NHB who experienced an increasing trend between 2001 and 2014 (APC = 2.08, p < 0.01) and plateauing afterward (APC = -1.21, p = 0.31); (AAPC = 1.03, p = 0.03). Among early-stage tumors (9927 patients), incidence rates were decreasing only in Hispanic (AAPC = -4.24, p = 0.006) while stable in other races/ethnicities (NHW: AAPC = -2.61, p = 0.39; NHB: AAPC = -1.73, p = 0.36). For regional-stage tumors (29,690 patients), GBC incidence rates were decreasing only in NHW (AAPC = -1.61, p < 0.001) while stable in other races/ethnicities (NHB: AAPC = 0.73, p = 0.34; Hispanic: AAPC = -1.58, p = 0.24; NHAPI: AAPC = -1.22, p = 0.07). For distant-stage tumors (31,735 patients), incidence rates were increasing in NHB (AAPC = 2.72, p < 0.001), decreasing in Hispanic (AAPC = -0.64, p = 0.04), and stable in NHW (AAPC = 0.07, p = 0.84) and NHAPI (AAPC = 0.79, p = 0.13). There were 43,411 deaths attributed to GBC with decreasing mortality rates in all races/ethnicities except NHB who experienced a stable trend (AAPC = 0.25, p = 0.25). CONCLUSION: Nationwide data over the last two decades show that NHB patients experienced increasing GBC incidence between 2001 and 2014 followed by stabilization of the rates. This increase was driven by late-stage tumors and occurred in the first decade. NHB also experienced non-improving GBC mortality, compared to other race and ethnic groups who had decreasing mortality. This can be due to lack of timely-access to healthcare leading to delayed diagnosis and worse outcomes. Future studies are warranted to investigate contributions to the revealed racial and ethnic disparities, especially in NHB, to improve early detection.

The National Landscapes of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma: Stable Trends in Black Populations and Late-Stage Tumors.

BACKGROUND: Helicobacter pylori (H. Pylori) eradication has been the mainstream for preventing and treating gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Prior data showed disparities in eradication rates of H. Pylori between different populations. This can potentially impact the occurrence of gastric MALT lymphoma. There are limited data on the incidence and mortality rates and trends of gastric MALT lymphoma in the US. Therefore, the aim of the current study was to conduct a time-trend analysis of gastric MALT lymphoma incidence and mortality rates in different populations. METHODS: The incidence rates of gastric MALT lymphoma were calculated from the United States Cancer Statistics (USCS) database (which covers nearly 98% of the US population) between 2001-2020 and were age-adjusted to the standard 2000 US population using SEER*Stat software (version 8.4.3, national cancer institute "NCI"). Incidence-based mortality (IBM) rates, also age-adjusted to the standard 2000 US population, were calculated from the Surveillance Epidemiology and End Results (SEER) database. Tumor location was specified using ICD-O-3 codes C 160-C 169 with malignant behavior. Histopathology was specified using the ICD-O-3 code 9699. The rates were categorized by sex, age, race/ethnicity, and tumor stage at diagnosis. Age groups were older adults (aged 55 years or older) and younger adults (aged younger than 55 years). Race/ethnic groups included Non-Hispanic White (White), Non-Hispanic Black (Black), Hispanic, Non-Hispanic Asian/Pacific Islander (API), and Non-Hispanic American Indian/Alaska Native (AI/AN), as reported in the database. Stage at diagnosis included early stage (in situ and localized tumors) and late stage (regional and distant site tumors). Joinpoint Regression Software (version 5.0.2, NCI) using the weighted Bayesian Information Criteria method was used to generate time trends. Trends were reported as annual percentage change (APC) and average APC (AAPC). Parametric estimations were used with a two-sided t-test to evaluate the trends with a p-value cutoff at 0.05. RESULTS: There were 21,625 patients diagnosed with gastric MALT lymphoma in the US between 2001 and 2020. Overall, incidence rates were significantly decreasing over the study period (AAPC = -1.93). This decrease was seen in males (AAPC = -1.67) and in females (AAPC = -1.66) (Figure). When categorized by age groups, older adults also experienced a significant decrease in gastric MALT lymphoma incidence rates (AAPC = -1.66). While this was also seen in younger adults, the rates were decreasing at a slower pace (AAPC = -1.38). When categorizing the trends by race/ethnicity, incidence rates were significantly decreasing in White (AAPC = -2.09), Hispanic (AAPC = -1.61), and API (AAPC = -3.92) populations. However, the rates were stable among Blacks. While early-stage tumors experienced a significant decrease (AAPC = -1.10), the rates were stable for late-stage tumors. When evaluating mortality, there were 11,036 patients whose death was attributed to gastric MALT lymphoma between 2000 and 2020. IBM rates were decreasing in males (AAPC = -1.47), older adults (AAPC = -1.55), Whites (AAPC = -1.23), Hispanics (AAPC = -1.73), APIs (AAPC = -2.30), and early-stage tumors (AAPC = -1.08). On the other hand, IBM rates were stable in females, younger adults, Blacks, and late-stage tumors. DISCUSSION: An extensive nationwide data analysis encompassing nearly 98% of patients diagnosed with gastric MALT lymphoma in the US unveils a declining trend in the incidence of cancer overall over the past two decades. This decline is observed in both sexes and various age groups. When stratifying by race and ethnicity, this incidence has been decreasing in all populations except among Black individuals. While early-stage tumors have also demonstrated a significant decrease in incidence rates, late-stage tumors have shown no parallel decline. Mortality evaluation also revealed an improvement in most of the US population except among females, younger adults, Black individuals, and late-stage tumors. While the cause of our findings is unclear, it could be driven by disproportionate exposure to risk factors, including H. Pylori, and disparities in screening, management, and outcomes. Future studies are warranted to investigate factors contributing to worse outcomes of gastric MALT lymphoma, especially in the Black population.

Geographical Variations in Early Onset Colorectal Cancer in the United States between 2001 and 2020.

BACKGROUND: Colorectal cancer remains the second leading cause of cancer-related death in the US. As early-onset colorectal cancer (EO-CRC) becomes more prevalent in the US, research attention has shifted towards identifying at-risk populations. Previous studies have highlighted the rising rate of early-onset adenocarcinoma (ADC) and neuroendocrine tumors (NET) in the US. However, data on geographical variations of EO-CRC are scarce. Hence, our study aims to analyze time trends in EO-CRC incidence rates across various US regions and to assess these trends by sex and histopathological subtypes (ADC and NET). METHODS: We analyze data spanning from 2001 to 2020 from the United States Cancer Statistics (USCS) database, covering nearly 98% of the US population. Using SEER*Stat software version (8.4.2, NCI), we calculated EO-CRC incidence rates among adults aged 20-54 years, adjusting for the age standard 2000 US population. The rates were categorized by sex and US geographical regions into west, midwest, northeast, and south. Time trends, reported as annual percentage change (APC) and average APC (AAPC), were generated via Joinpoint Regression software (v.5.0.2, NCI) utilizing the weighted Bayesian Information Criteria "BIC" method to generate the best-fit trends with a two-sided p-value cutoff at 0.05. The rates were also stratified by histopathology into ADC and NET. RESULTS: Between 2001 and 2020, a total of 514,875 individuals were diagnosed with early-onset CRC in the US, with 54.78% being men. Incidence rates and trends varied across geographical regions. In the western region (comprising 106,685 patients, 54.85% men), incidence rates significantly increased in both women (AAPC = 1.37, p < 0.001) and men (AAPC = 1.34, p < 0.001). Similarly, in the midwestern region (with 110,380 patients, 55.46% men), there were significant increases in incidence rates among women (AAPC = 1.06, p < 0.001) and men (AAPC = 1.35, p < 0.001). The northeastern region (with 94,758 patients, 54.53% men) also witnessed significant increases in incidence rates for both women (AAPC = 0.71, p < 0.001) and men (AAPC = 0.84, p < 0.001). In contrast, the southern region (with 203,052 patients, 54.48% men) experienced slower increases in incidence rates among both women and men (AAPC = 0.25, p < 0.05 in women; AAPC = 0.66, p < 0.05 in men). When stratified by histopathology, incidence rates for adenocarcinomas (ADC) increased in all regions, most notably in the west (AAPC = 1.45, p < 0.05), and least in the south (AAPC = 0.46, p < 0.05). Conversely, for neuroendocrine tumors (NET), while incidence rates increased similarly across all regions, the pace was notably faster compared to ADC, particularly in the west (AAPC = 3.26, p < 0.05) and slower in the south (AAPC = 2.24, p < 0.05) Discussion: Our analysis of nationwide US data spanning two decades and encompassing over half a million early-onset CRC patients, representing nearly 98% of the US population, highlights significant temporal variation in incidence rates across various geographical regions. The most substantial increases in incidence rates were observed in the west, while the least pronounced changes were noted in the south, affecting both men and women. These trends persisted across the main CRC histopathological subtypes, with NET exhibiting a notably swifter pace of increase compared with ADC. These findings hold important implications for public health strategies and underscore the need for targeted interventions to address the rising burden of early-onset CRC across different regions in the US.