Population-Based Trends in Malignant Mesothelioma: Racial and Gender Patterns from SEER, 1975–2022.

Malignant mesothelioma is a rare, aggressive neoplasm predominantly associated with asbestos exposure, with incidence and mortality trends varying by gender and race. The United States Surveillance, Epidemiology, and End Results (SEER) database provides a comprehensive resource for evaluating long-term epidemiological patterns.

Annual case counts for mesothelioma from 1975 to 2022 were extracted from the SEER database, stratified by race (White, Black, Other [American Indian/Alaska Native, Asian/Pacific Islander]) and gender. Trends were analysed as annual percentages of total cases, allowing for the assessment of continuous changes over time.

Between 1975 and 2022, a total of 9,798 cases of mesothelioma were reported. Males accounted for 77.6% of cases, with Whites comprising 91% of all cases. The proportion of male cases peaked in the late 1980s (e.g., 1989: 81.8%) and declined steadily thereafter, reaching 77.6% in 2022. Female cases remained relatively stable, averaging 22.4% annually, with no significant upward or downward trend. The annual analysis based on racial trends shows that, before 2000, mesothelioma cases increased by approximately 2.2% per year for all races, and then declined by 1.2% per year thereafter. Among Whites, cases rose by 3.1% per year until 2005, then fell by 1.6% per year. Cases among Blacks increased slightly, about 0.2% per year, and remained stable. For Other races, cases rose by 0.4% per year until 2014, then stabilised. White patients consistently represented the majority, but their share decreased from 89.4% in 1975 to 87.2% in 2022. Black cases increased modestly from 4.3% in 1975 to 6.1% in 2022, while "Other" races (American Indian/Alaska Native, Asian/Pacific Islander) rose from 5.3% to 6.6% over the same period. The annual percentage of Black male cases increased from 3.2% in 1975 to 6.6% in 2022, while Black female cases remained low, fluctuating between 0% and 3%. Notably, the proportion of cases with unknown race or gender remained negligible throughout the study period.

The incidence of mesothelioma in the United States has declined among males since the 1990s, while rates among females have remained relatively stable. Racial disparities persist, with Whites comprising the majority but a relative increase in Black and "Other" racial groups over time. These findings align with national epidemiological patterns and underscore the importance of ongoing surveillance and targeted prevention efforts.