Mesothelioma Latency Period
Because asbestos use was largely banned at the end of the 1970s, logic tells us that asbestos-caused diseases, including mesothelioma, should be pretty much non-existent at this point. People rejoiced at the new asbestos warnings, recognizing, nonetheless, that many had already been negatively affected by the material but understanding that the next generation would be fortunate enough to avoid exposure.
So why are there 2,000 to 3,000 new cases diagnosed each year in the United States? The answer is simple though sometimes difficult to grasp, especially for those who were exposed to the mineral on a regular basis many years ago, when asbestos use was abundant, and thought perhaps they had escaped the hazards of this toxic material.
Simply put, mesothelioma has a long latency period, often up to 50 years. That means that those exposed to asbestos before the warnings were issued in the late 70s are still candidates for developing the disease. For those who are eventually diagnosed with mesothelioma in their later years, that’s a brutal blow.
A latency period is best described as the time between the exposure to a disease-causing agent and the time the disease appears. Mesothelioma has one of the longest latency periods of all diseases, and its sister disease, asbestosis, does as well – usually taking about 10 to 20 years to be detected.
Variations in Latency
For decades, scientists have been studying the latency period of malignant mesothelioma. While researchers agree that no amount of asbestos is safe, numbers seem to indicate that the level of exposure, not the length, may determine who will get the disease and how long it may remain latent.
For example, some numbers show that those who worked in industries where asbestos exposure was consistent and use of the mineral was abundant are more likely to have a shorter latency period than those who were consistently exposed to lower levels of the toxic mineral, even if for many years. This includes, for example, shipbuilders and construction workers who were exposed to asbestos on an almost-daily basis.
Therefore, the conclusion has been made that the intensity of exposure definitely plays a role in the length of the latency period. Another prime example of this is the death of Sept. 11th emergency responder Deborah Reeve, who died of mesothelioma just five years after the tragedy and was exhibiting symptoms as early as 2 years after the World Trade Center fell. Others suffered from similar circumstances. These facts indicate that Reeve and her fellow responders were exposed to a very high level of asbestos and also gives a nod to the fact that intense exposure for a short amount of time may be more dangerous than low exposure for many years.
Dealing with the Latency Period
No one expects those who were exposed to asbestos in their earlier years to sit around and worry about developing the disease as they age. Because mesothelioma is a rare cancer, many people will be spared this suffering and enjoy their lives unscathed by past exposure.
Those who have been exposed and spend time worrying about their health, however, can do a few things on a regular basis to quell their fears. For decades, doctors have been recommending regular chest x-rays for those who were exposed to asbestos in the past. These are simple procedures that are usually covered by medical insurance. Individuals with a history of asbestos exposure may also wish to undergo a lung function test on an annual basis in order to establish whether or not their lungs are working properly.
Because the long latency period also means that the cancer has usually reached Stage 3 or 4 by the time it is discovered, scientists have continuously looked for better ways to diagnose the disease at an earlier stage. In 2007, the U.S. Food and Drug Administration approved the use of the Mesomark® test, a simple blood test that can detect certain levels of a cancer biomarker in a person’s blood, catching the disease before it has progressed. Ask your doctor if you are a candidate for this test and where it can be performed.
- American Cancer Society: "How is Malignant Mesothelioma Diagnosed". http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_malignant_mesothelioma_diagnosed_29.asp?rnav=cri
Last modified: April 15, 2010.