Right now, the gold standard for mesothelioma diagnosis is examination of suspected tumor cells under a microscope. To get those cells, doctors have to perform either an open surgery called thoracotomy or a less invasive operation called thoracoscopy using smaller incisions and a camera for guidance.
But biomedical engineers at Carnegie Mellon University in Pittsburgh say analyzing cells in the fluid around the lungs may be just as effective. Unlike diagnostic methods that use tissue samples, the pleural fluid method requires only a thoracentesis, or removal of a sample of lung fluid using a needle. To maximize the diagnostic power of fluid samples, the researchers developed a computer program that analyzes the distribution of chromatin (the material that becomes DNA and RNA) in the nuclei of suspected cancer cells.
To test the method against standard diagnostic tools, the researchers used pleural effusion (excess fluid) samples from 34 people already diagnosed with mesothelioma using standard methods. They looked at digital images of the mesothelial cells that were suspended in the fluid, and then applied their own image analysis technique for determining whether each cell’s chromatin distribution pattern indicated cancer. The results may dramatically change the future of mesothelioma diagnosis.
“Our experiments on 34 different human cases result in 100% accurate predictions computed with blind cross validation,” writes lead author Dr. Akif Burak Tosun, a postdoctoral researcher in Carnegie Mellon’s Department of Biomedical Engineering. Dr. Tosun goes on to say that, not only was the new method as effective as methods requiring pleural biopsy, but it also outperformed any other methods that rely on counting certain cellular features.
One of the biggest challenges of mesothelioma diagnosis is not only separating this deadly asbestos cancer from other types of cancer, but also distinguishing it from a benign condition called benign mesothelial proliferation. Dr. Tosun and his colleagues say their experiments indicate that simply analyzing the nuclei of these cells using their image analysis technique may be enough to separate malignant cells from benign cells. Their new study is published in the journal Cytometry.
Tosun, AB et al, “Detection of malignant mesothelioma using muclear structure of mesothelial cells in effusion cytology speciments”, January 16, 2015, Cytometry, Part A, Epub ahead of print