What Type of Mesothelioma Do I Have? CT May Be Able to Tell

Researchers from one of the country’s top cancer centers say it may be possible to tell what subtype of pleural mesothelioma a person has by using computed tomography (CT).

Pleural mesothelioma is an aggressive lung-related cancer for which patients and their doctors must develop a treatment plan quickly to get ahead of the disease. The challenge is that, not only is mesothelioma highly resistant to standard cancer treatment, but different subtypes of mesothelioma are often managed with different drugs and therapies.

The new study from Memorial Sloan Kettering Cancer Center in New York suggests that CT may offer an accurate and non-invasive way to classify mesothelioma patients which could speed the treatment planning process and lead to longer mesothelioma survival.

Computed Tomography for Mesothelioma Diagnosis

The new study focuses on computed tomography or CT,  an imaging tool that compiles a series of X-ray images into a three dimensional model of the inside of the body.

People with suspected malignant mesothelioma are often recommended for a CT scan so that doctors can see if there are masses, excess fluid, or calcified areas in their chest that could indicate cancer.

To improve the accuracy of a CT scan, it may be combined with a contrast material, a dye that temporarily changes the way certain types of tissues appear on X-rays. In combination with contrast materials, CT scans can help doctors determine if mesothelioma cells have spread to lymph nodes, nearby tissues or other organs.

Identifying Mesothelioma Subtypes with CT

The new CT study of mesothelioma subtypes included 125 patients with malignant pleural mesothelioma.

Ninety-seven of the patients (77%) had the epithelioid mesothelioma subtype, the type of mesothelioma that this not only most common but also most receptive to treatment. Seventeen patients (14%) had the biphasic mesothelioma subtype and 11 (9%) had the sarcomatoid mesothelioma.

Most of the patients in the study had a common symptom of mesothelioma called pleural plaques, non-cancerous thickened, fibrous areas on the the pleural lining around the lungs.

Most of the time, pleural plaques are not calcified, meaning they have not been hardened by deposits of soluble calcium. But the study found that people who had either one of the non-epithelioid subtypes of pleural mesothelioma were much more likely to have calcified pleural plaques.

“Calcified plaques are significantly more common in non-epithelioid subtypes compared with epithelioid malignant pleural mesothelioma,” writes radiologist Joanna Escalon, MD, in the Journal of Computer Assisted Tomography. “Given the different prognoses and management of malignant pleural mesothelioma subtypes, accurate noninvasive subtype classification is clinically vital.”

CT is now being used in some places to screen heavy smokers for early signs of lung cancer and it has been suggested that it might also be useful for screening asbestos-exposed people in order to diagnose mesothelioma earlier.

Source:

Escalon, JG, et al, “Malignant Pleural Mesothelioma: Are There Imaging Characteristics Associated With Different Histologic Subtypes on Computed Tomography?”, April 2, 2018, Journal of Computer Assisted Tomography, Epub ahead of print