New Study Shows Mesothelioma’s Burden Remains Significant

Mesothelioma is often described as a disease of the past, linked to an era when asbestos was widely used in shipyards, factories, construction sites and military equipment across the United States. Yet a new nationwide study suggests that the impact of those exposures continues to be felt today, decades after many Americans first encountered asbestos.

The study, “Geographic, Temporal, and Sex-Specific Trends in Mesothelioma Burden in the United States, 1990-2023,” appeared in JCO Global Oncology and examined mesothelioma incidence, mortality and disability burden across all 50 states over a 33-year period.

The findings reveal both progress and ongoing challenges. While age-adjusted mesothelioma rates have declined nationwide, the total number of Americans diagnosed with and dying from the disease continues to increase.

A Cancer with a Long Memory

Mesothelioma is a rare and aggressive cancer caused by asbestos exposure. It most commonly develops in the lining of the lungs, although it can also occur in the abdomen, heart or testes.

One of the most challenging aspects of mesothelioma is its unusually long latency period. Many patients are not diagnosed until 20 to 50 years after exposure to asbestos.

“Mesothelioma behaves like a time capsule,” said Chinmay Jani, M.D., Chief Fellow at Sylvester Comprehensive Cancer Center and co-lead author of the study. “What we’re seeing today reflects exposures that happened 30 or 40 years ago, and in some cases, exposures that are still happening in quieter, less visible ways.”

For decades, asbestos was widely used in shipbuilding, construction, insulation, manufacturing and military equipment because of its heat-resistant properties. Although regulations reduced its use beginning in the 1970s, asbestos was never fully banned in the United States. In addition, legacy asbestos that had already been introduced into the environment was not removed as part of those regulations. Many older homes, schools, factories and public buildings still contain asbestos materials today.

At first glance, the national trend appears encouraging. Researchers found that age-standardized incidence rates and mortality rates declined substantially between 1990 and 2023, reflecting reduced asbestos exposure over time.

However, those declining rates do not tell the whole story.

The study found that annual mesothelioma cases increased from approximately 2,094 cases in 1990 to 2,675 cases in 2023, an increase of nearly 28%. Annual deaths also rose during the same period. Researchers attribute this trend largely to population growth and an aging population, both of which increase the number of people reaching the age when mesothelioma typically develops.

The disease’s overall disability burden also increased. In 2023, mesothelioma accounted for more than 48,000 disability-adjusted life years (DALYs), representing a 14% increase compared to 1990.

“Declining rates don’t necessarily mean fewer lives affected,” said Kyle Edwards, co-lead author and M.D./M.P.H. student at the University of Miami Miller School of Medicine. “When you look at absolute numbers and disability, mesothelioma remains a substantial public health problem.”

Important Differences Between Men and Women, and Between States

Historically, mesothelioma has affected men at much higher rates because many of the occupations with heavy asbestos exposure, including shipbuilding, construction and insulation work, were predominantly male industries.

The study found that incidence and mortality rates among men declined significantly over the study period. Among women, however, declines were much smaller and often not statistically significant at the national level.

Researchers also identified concerning state-level trends. Female mesothelioma incidence increased in 20 states, while female mortality increased in 18 states. In addition, the number of female mesothelioma cases grew substantially over the study period, increasing at a faster rate than male cases.

These findings suggest that many women may be exposed through pathways outside of traditional occupational settings.

“For women, mesothelioma often doesn’t come with a neat occupational history,” said Estelamari Rodriguez, M.D., M.P.H., Clinical Research Lead of the Thoracic Oncology Site Disease Group at Sylvester. “Environmental exposure, para-occupational exposure from family members and legacy asbestos in schools, homes and public buildings likely play a much larger role.”

Para-occupational exposure, also known as second and third hand exposure, occurs when asbestos fibers are carried home on work clothing, shoes or equipment, exposing family members who never worked directly with asbestos themselves.

Geography Continues to Shape Risk

The study also demonstrated that where a person lives can significantly influence their mesothelioma risk.

States such as Maine, Alaska, Washington and Minnesota consistently showed some of the highest incidence, mortality and disability burdens in 2023.

Researchers believe these geographic differences reflect a combination of historical shipbuilding activity, industrial asbestos use, mining operations and naturally occurring asbestos deposits that can be disturbed during construction and excavation.

“Mesothelioma is a geographic disease,” Jani said. “State-level data allow us to see where prevention, remediation and surveillance efforts are most urgently needed.”

The authors note that national averages can sometimes obscure these regional patterns and local risks.

Survival Remains a Major Challenge

Perhaps the most sobering finding from the study is how little overall survival appears to have improved at the population level.

Researchers examined the mortality-to-incidence ratio (MIR), a commonly used population-level indicator that can provide insight into survival outcomes. Despite advances in treatment, including the introduction of immunotherapy and immune checkpoint inhibitors in recent years, the MIR remained extremely high throughout the study period and even increased slightly over time.

In practical terms, this means that most people diagnosed with mesothelioma still die from the disease.

“From a patient’s perspective, this is the hardest message,” said Gilberto Lopes, M.D., Sylvester’s Chief of Medical Oncology. “Despite all our scientific advances, mesothelioma remains one of the most lethal solid tumors.”

While newer treatments have improved outcomes for some patients, the study suggests these advances are only effective for a minority of patients.

Asbestos Continues to be a Current and Present Danger

The study also reinforced an important reality: mesothelioma is largely preventable.

Researchers estimated that nearly 96% of mesothelioma deaths in 2023 were attributable to occupational asbestos exposure, a proportion that has remained consistent over time.

Although new asbestos use has declined substantially, asbestos-containing materials that were introduced into our environment over many decades remain present in many older homes, schools, commercial buildings, ships and industrial facilities throughout the country. As these materials age or are disturbed during renovations and demolition projects, exposure risks persist.

The authors conclude that reducing the future burden of mesothelioma will require continued investment in both asbestos prevention and treatment research.

“Mesothelioma reminds us that prevention and treatment are inseparable,” Lopes said. “We have to keep people from being exposed in the first place, while also doing better for those who are diagnosed.”

While mesothelioma rates have fallen over the past three decades, this study demonstrates that the disease remains a significant public health challenge. The findings highlight persistent geographic disparities and growing concerns about nontraditional exposure pathways. Most importantly, they serve as a reminder that the consequences of asbestos exposure can last a lifetime, making continued prevention efforts as important as ever.