01. How Long Is the Mesothelioma Latency Period?
How Long Does It Take for Mesothelioma to Develop?
Latency period is the time between initial asbestos exposure and a mesothelioma diagnosis. It commonly ranges from 10 – 50 years. But there is no single answer for how long it takes for mesothelioma to develop. Mesothelioma latency period varies from person to person. Factors such as occupation and age may affect how long after asbestos exposure mesothelioma presents.
Mesothelioma latency is both long and variable. According to one study, 96% of mesothelioma cases have a latency period of at least 20 years.
A person may develop mesothelioma decades after their initial asbestos exposure. Anyone who knows they have been exposed to asbestos should talk to a mesothelioma doctor. A doctor can help patients track their health over time and watch for signs of mesothelioma.
Why Mesothelioma Has a Long Latency Period
Latency period is an indicator of how long it takes for asbestos to cause mesothelioma. The exact process by which mesothelioma develops is still not known for sure. But it is clear that many cellular changes are necessary for mesothelioma to develop.
The following steps may occur during mesothelioma cancer’s latency period:
- Step 1: A person ingests or inhales asbestos fibers.
- Step 2: The asbestos fibers settle near mesothelial cells.
- Step 3: The asbestos fibers cause inflammation in the area around where they settled.
- Step 4: The inflammation creates biological responses leading to cancer development.
Experts still do not know if these are the correct steps. It is also possible that more exist.
Cells have many protections against the types of genetic changes that cause cancer. It is possible the effects of asbestos in the body have to continue for a long time to penetrate all the layers of protection that cells have. This may help explain how long it takes for mesothelioma to develop.
Latency Period for Other Asbestos-Related Diseases
Asbestos-related diseases such as asbestosis also have long, variable latency periods. These diseases do not develop until years after initial asbestos exposure. The latency periods for asbestos-related diseases vary depending on the specific diagnosis.
- Asbestosis: Asbestosis may present 15 years or more after asbestos exposure.
- Lung cancer: Lung cancer may present 10 years or more after asbestos exposure.
- Pleural plaques: Plaques tend to develop 20 – 30 years after asbestos exposure.
How latency works is very complex. Various factors may affect latency periods for asbestos cancers and other asbestos-related diseases.
Resources for Mesothelioma Patients
02. Latency Period and Asbestos Exposure
How Does Asbestos Exposure Affect Latency Period?
The factors leading to different latency periods are complex and varied. The nature of a person’s asbestos exposure may impact latency period. Certain occupations, such as insulators and shipyard workers, may experience shorter latency periods. Exposure intensity and secondhand exposure may also affect mesothelioma latency period.
Duration and Concentration of Asbestos Exposure
Asbestos latency period may be impacted by an individual’s duration and concentration of asbestos exposure. For instance, one idea about asbestos exposure connects higher intensity to shorter latency.
Intensity refers to the duration and concentration of exposure. Further research may show a person exposed to asbestos for a long time and/or to a high amount of fibers may experience a shorter latency period.
Situations that may result in a long duration of exposure include:
- Longtime use of asbestos products
- Working at an asbestos company
- Working at multiple asbestos jobsites
Situations that may result in a high concentration of asbestos exposure include:
- Working in areas with poor ventilation
- Working in enclosed areas
- Working with asbestos-containing materials and products
The idea that intensity affects latency period is still a hypothesis. It is possible that duration and concentration of asbestos exposure affect mesothelioma latency. But further research is needed to determine if this may be true.
The Impact of Occupation on Asbestos Latency Period
Occupation may affect a person’s mesothelioma latency period. One study observed different latency periods among different types of workers. These workers, such as insulators and shipyard workers, worked in industries known to carry risks of asbestos exposure. Many industries used asbestos in products that their workers handled. Other industries provided services that exposed their workers to asbestos.
Median Latency Period by Occupation |
|
|---|---|
| Occupation | Median Latency Period |
| Insulation Workers | 29.6 years |
| Dock Workers | 35.4 years |
| Non-shipbuilding Industrial Workers | 46.4 years |
| Shipyard Workers | 49.4 years |
| Women With a History of Domestic Exposure | 51.7 years |
| Source: European Journal of Cancer Prevention | |
Research has shown an association between certain occupations and shorter latency periods. Researchers are not sure why certain occupations may lead to shorter latency periods. Even so, there is data suggesting that this is the case.
One study examined the occupations of more than 400 people with pleural mesothelioma. Researchers found notable differences between latency periods when they organized people by occupation.
Among the mesothelioma cases reviewed, insulators had the shortest median latency. Their median latency period was 29.6 years. The longest median latency was among women with a history of domestic exposure. Their median latency period was 51.7 years.
This research suggests that occupational asbestos exposure may affect mesothelioma latency periods.
Secondhand Exposure
Secondhand exposure may also impact mesothelioma latency period. Secondary asbestos exposure often results in a lower intensity of asbestos exposure. Intensity refers to both the duration and concentration of exposure.
Some researchers have suggested that exposure intensity may affect latency periods. They have theorized that higher intensity leads to shorter latency. However, any level of asbestos exposure is unsafe and can result in mesothelioma.
It can be more difficult for people to determine when secondhand exposure occurred than direct exposure. For example, family members of asbestos workers may be exposed to asbestos fibers on the workers’ clothes. It can be difficult to determine when an exposure like this first occurred.
Further research may clarify the relationship between secondhand exposure and latency.
03. Latency Period and Factors Other Than Asbestos Exposure
What Other Factors Impact Mesothelioma Latency Period?
Asbestos exposure is not the only thing that may affect latency period. Other factors may impact the latency period for mesothelioma as well. These factors include gender, age, mesothelioma type and co-occurring diseases.
Gender
A person’s gender may influence the latency period of mesothelioma. Research has shown that women tend to experience longer latency periods than men. One study found that women experience latency periods almost 30% longer than men.
- Median latency period for men with mesothelioma: 22.2 years
- Median latency period for women with mesothelioma: 28.2 years
It is not clear why gender affects latency, despite data to support this idea. Some researchers think this data may support the intensity theory of asbestos exposure. This theory suggests that intensity of asbestos exposure affects mesothelioma latency periods.
Women are more likely than men to experience secondhand asbestos exposure. Secondhand exposure tends to be less intense than firsthand exposure. So women may experience longer latencies due to lower exposure intensities. However, this requires further research to confirm.
Age
A person’s age when they were first exposed to asbestos may influence mesothelioma latency period. According to one study, people exposed at a later age have shorter median latency periods than those exposed at a younger age.
Latency Period by Age of First Asbestos Exposure |
|
|---|---|
| Age at First Exposure | Median Latency Period |
| <20 years | 40.6 years |
| 20 – 29 years | 34.5 years |
| 30 – 39 years | 30.2 years |
| 40 – 49 years | 18.2 years |
| 50 years | 10.7 years |
As with other potential latency factors, researchers are still investigating the impact of age on asbestos latency period. The above data is based on a single study. Further research can help shed more light on the relationship between age of first asbestos exposure and latency period.
Type of Mesothelioma and Co-Occurring Diseases
The type of mesothelioma a person develops may affect latency period. The existence of diseases co-occurring with mesothelioma may also affect latency period.
A person may develop different types of mesothelioma. The type depends on where the cancer presents in the body. Different types of mesothelioma may take longer to present than others.
- Pleural mesothelioma: This type of mesothelioma has a median latency period of 22.9 years. The risk of pleural mesothelioma increases with time up to 45 years after exposure. After 45 years, the risk of developing it increases at a slower rate.
- Peritoneal mesothelioma: This type of mesothelioma has a median latency period of 8.2 years. The risk of peritoneal mesothelioma increases over time.
Co-occurring diseases may also affect mesothelioma latency periods. One study noted a difference between mesothelioma patients with and without asbestosis. It found that patients with both conditions had about a 5% shorter mesothelioma latency period.
People can develop mesothelioma slower or faster based on several factors. Researchers continue to study the potential factors that may impact mesothelioma latency period.
04. Latency Period and Diagnosis
How Does Mesothelioma Latency Period Impact Diagnosis?
A long latency period may impact the time required to obtain an accurate mesothelioma diagnosis. For example, a person may not know that they were exposed to asbestos. This can lead to a later diagnosis if a person is not receiving regular checkups. It can also be difficult to recognize the symptoms of mesothelioma. This can impact the time of diagnosis as well.
In this sense, latency periods may make it more difficult for patients to receive a timely diagnosis. Mesothelioma latency is defined as the amount of time between initial exposure and diagnosis.
But there is no evidence that latency period affects a person’s mesothelioma prognosis. Prognosis refers to how a person’s mesothelioma is expected to progress and develop. Things that do affect prognosis include type of mesothelioma, treatment and a patient’s overall health.
It is important that people exposed to asbestos see a doctor. People should talk to a doctor even if they only suspect they have been exposed. A doctor can help track a patient’s health through regular checkups. But patients should also alert their doctor if any mesothelioma symptoms develop.
Working closely with a mesothelioma doctor can help lead to a timely diagnosis. Mesothelioma treatment may be more effective if the disease is caught in its early stages.
