Low-Dose CT Screening May Delay Mesothelioma Deaths

The results of a long-term national study suggest that low-dose CT screening might prevent – or at least delay – deaths from pleural mesothelioma. 

The National Lung Screening Trial included more than 53,000 lung cancer patients. Researchers released the first results in 2011 after more than six years of study.

The recent follow-up results reflect more than 12 years of data on low-dose CT screening. They show that, in many cases, screening lung cancer patients for at least three years delayed their deaths for more than a decade. 

Pleural Mesothelioma and Lung Cancer

Pleural mesothelioma is not the same thing as lung cancer. Mesothelioma starts on the lining around the lungs (pleura), rather than in the lung tissue itself. 

But mesothelioma does share many of the same symptoms and characteristics as non-small cell lung cancer. Some of the treatments are also similar.

For this reason, researchers have suggested that low-dose CT might extend survival in mesothelioma patients, just as it has with lung cancer. 

Like lung cancer, pleural mesothelioma typically carries a poor prognosis. Malignant mesothelioma is a very aggressive cancer. With standard treatment, average mesothelioma survival is about a year. Survival is higher in people whose disease is recognized early. 

Low-Dose CT Screening Could Catch Cancer Early

The goal of low-dose CT screening is to identify cancer earlier, when it is more likely to respond to treatment. The US Preventative Services Task Force and other groups already recommend LDCT for heavy smokers because of their high lung cancer risk.

The highest risk for pleural mesothelioma occurs among people who worked around asbestos. An effective screening tool for asbestos-exposed workers might improve their survival odds, too.

The new National Lung Screening Trial results reaffirm the earlier findings: Annual low-dose CT screening of high-risk patients reduced the risk of lung cancer by 20 percent.

The findings also backed up a separate study showing that LDCT led to a 26% reduction in lung cancer deaths in men and a 39% reduction in women.

LDCT Still Controversial

In 2016,  Germany’s statutory accident insurance began covering low-dose CT screening for asbestos workers at risk of mesothelioma. A pair of radiology researchers summed up the decision in an article in the journal Radiologe. 

But not everyone agrees with the approach. Critics say LDCT for mesothelioma and lung cancer can lead to unnecessary radiation exposure, false positive results, overtreatment, and unneeded surgeries. 

An estimated 2,500 Americans receive a mesothelioma diagnosis each year. Most have Stage III or IV cancer by the time they are diagnosed. 

Sources:

Black, W, et al, “Lung Cancer Incidence and Mortality with Extended Follow-up in the National Lung Screening Trial National Lung Screening Trial Writing Team 1”, May 31, 2019, Journal of Thoracic Oncology, https://www.jto.org/article/S1556-0864(19)30473-3/fulltext

Hofmann-Preiss, K and Rehbock, B, “Early recognition of lung cancer in workers occupationally exposed to asbestos”, September 2016, Radiologe, pp. 810 – 816, https://link.springer.com/article/10.1007%2Fs00117-016-0151-5