Decreases in lung volume may be an indicator of treatment response for patients with mesothelioma. Researchers in the U.S. and Australia reached that conclusion after studying the cases of 61 patients with malignant pleural mesothelioma and 216 CT scans taken of them during the course of their standard chemotherapy treatment.
Lung volume is a measurement of the amount of air the lung processes (inhales, exhales and holds on to) during the course of a normal breath. People with malignant pleural mesothelioma, a cancer that starts on the lining around the lungs, typically experience a drop in lung volume as the pleural tumor grows and constricts or even invades one of their lungs.
The new study measured changes in each mesothelioma patient’s lung volume by comparing the diseased lung to the volume of the healthy lung. They also followed changes in the linear thickness of their mesothelioma tumors as well as overall disease volume. The goal of the study was to determine how these factors relate to each other and what information they could give doctors about how each patient was responding to treatment.
Predictably, the study found that, as lung volumes decreased, disease volume (the amount of cancer in the body) increased. At the same time, increases in linear thickness of the mesothelioma tumors corresponded to increases in overall disease volume. The researchers concluded that all three assessment methods could be effective as independent imaging biomarkers of each patient’s prognosis. Writing in the Journal of Thoracic Oncology, the study’s authors summarize, “Increasing linear thickness, increasing disease volume, and decreasing lung volume are all significantly and independently associated with poor patient prognosis.”
Other prognostic indicators may include blood biomarkers, certain patient characteristics (such as age or gender), and length and intensity of asbestos exposure. While the Environmental Protection Agency has said that there is no safe level of asbestos exposure, medical research has found that the longer patients are exposed to the toxic mineral, the greater their chances of developing mesothelioma even decades later.