Mesothelioma Latency Period

Mesothelioma usually takes between 20 and 50 years to develop. This time frame is called the mesothelioma latency period.


Written by Jenna Campagna, RN


Fact Checked


What Is Mesothelioma Latency Period?

Mesothelioma latency period is the time between a person’s asbestos exposure and their mesothelioma diagnosis. It often lasts multiple decades.

There is no safe asbestos exposure level. Any amount of inhaled or ingested fibers, if they’re not purged from the body, can cause mesothelioma.

Why Does Mesothelioma Take So Long to Develop?

Mesothelioma takes so long to develop because the process involved does not occur immediately. Each patient’s latency period is different, but the disease forms in the same biological way: asbestos exposure.

When asbestos fibers are inhaled or ingested, they become lodged in the protective coating of the lung cavity or abdominal cavity. The cellular linings in these membranes are collectively known as the mesothelium.

These sharp asbestos fibers cause scarring and inflammation in the mesothelium, ultimately leading to the formation of tumors. This scarring and inflammation occurs very slowly, though. Then the tumors must form, which also happens during the span of many years.

Most estimates find the average latency period for mesothelioma patients is approximately 40 years. One study of 1,690 mesothelioma patients found that only 4% were diagnosed within 20 years of their exposure.

Factors Affecting Mesothelioma Latency Period

There are several factors that may contribute to the amount of time it takes for mesothelioma to develop. These factors coincide with the general risk factors of developing mesothelioma.


Duration of Exposure

The longer someone is exposed to asbestos, their risk of mesothelioma increases and their latency period is likely to decrease. More fibers enter the body the longer someone is exposed to asbestos.

As more fibers irritate cells, the chances of mesothelioma forming quicker increase. Duration of exposure is also why specific occupations are more at risk of developing mesothelioma.


Amount of Exposure

The frequency of exposure and the concentration of asbestos fibers both play a role in the amount of exposure. Shorter latency periods are caused by continually inhaling or ingesting large amounts of asbestos.

The more sharp fibers enter the body, the higher likelihood that a few of them lodge into and irritate cells along the mesothelium. This increases the chances of mesothelioma forming quickly.



A person’s occupation can have a big impact on the latency period of their mesothelioma. Occupational asbestos exposure is more common in industrial trades, and certain trades exposed workers to higher concentrations of the substance.

Mining, a profession already known for its correlation to respiratory conditions, has exposed workers to large amounts of asbestos in a confined space where breathing is already limited. The most devastating example of this occurred in the mining town of Libby, Montana.

There is a synergistic effect between the concentration of asbestos and the heightened breathing rates of workers in conditions like these. This is because they are inclined to inhale large amounts of asbestos.

A few occupations at risk of a high amount of asbestos exposure


Shipyard Workers




Insulation Workers



Effects of Mesothelioma Latency Period



Mesothelioma is one of the hardest diseases to diagnose, which is largely due to the cancer’s long latency period. Many people do not connect their mesothelioma symptoms to their past asbestos exposure since they occur decades apart.

Therefore, diagnosing mesothelioma is difficult and often doesn’t happen until the disease is advanced. Patients often receive a discouraging prognosis, and they should consider seeking a second opinion.



The long mesothelioma latency period can also affect treatment. Since mesothelioma is difficult to diagnose, the disease often isn’t identified until it’s advanced. If a mesothelioma has metastasized, it may not have many treatment options.

The long mesothelioma latency period also leads to most patients being elderly. Some patients are too old — and too weak — to endure curative treatment options like invasive surgery.

However, patients should seek options. Emerging treatment methods, such as immunotherapy, are in clinical testing and could be available to those who aren’t surgical candidates.

Improving Diagnosis and Prognosis

Understanding the latency period of mesothelioma is important to diagnosing mesothelioma at earlier stages. Scientists and mesothelioma specialists are hoping to increase survival times by catching the disease earlier.

Unfortunately, mesothelioma is typically only diagnosed after a patient has started experiencing symptoms. In the early stages of mesothelioma, symptoms can be minor or may not be present at all.

The mesothelioma latency period is considered to be one of the main culprits of the delayed diagnosis, which leads to a poor prognosis. As a patient, you should understand that while the latency period is beyond your control, your mesothelioma prognosis is not.

Getting a second opinion can reveal a better prognosis than previously given. If you were diagnosed with mesothelioma, then you should see a specialist who is experienced in diagnosing the disease.

Receiving the best treatment possible, including clinical trials, may present patients with new opportunities for treatment and also provide financial and prognostic perks. We can help you find a specialist for a second opinion through our free Doctor Match program.

Common Questions About Mesothelioma Latency Period

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What does the “latency period” mean for mesothelioma?

Latency period is how long a disease takes to develop. Mesothelioma has a lengthy latency period, of at least 20 years and sometimes as much as 50 years. The long amount of time between exposure and development is why mesothelioma is hard to detect. Patients also struggle to piece together what caused their cancer.

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What can affect the latency period for mesothelioma?

There are multiple factors that can dictate an individual’s mesothelioma latency period. The most important detail is asbestos exposure, explicitly how much enters a person’s body. People who worked jobs that involved regular exposure to asbestos are more likely to have a shorter latency period.

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How does latency period affect treatment?

A long latency period means patients are often elderly, which can limit treatment. If a latency period is just 20-30 years, then the patient may be young and strong enough to withstand surgery and other treatment options.

Last Edited: October 22, 2020.

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