A recent study adds to the growing body of research into breath analysis as a diagnostic and treatment-monitoring tool
More progress is being made on the diagnosis and treatment of lung cancer. The newest developments will be of interest to anatomic pathologists who work with lung specimens. A new study suggests it is possible to use breath specimens to monitor the progress of lung cancer patients undergoing therapy.
The study was conducted by Inbar Nardi-Agmon, MD, Thoracic Cancer Research and Detection Center at Sheba Medical Center, Tel-Aviv, Israel, and colleagues, and was published in the Journal of Thoracic Oncology (JTO). The study investigated the use of breath analysis to monitor lung cancer therapy.
The authors of the study took 143 exhaled breath samples from 39 patients who were undergoing treatment for advanced lung cancer. They used gas chromatography and mass spectrometry analysis to identify three different volatile organic compounds (VOCs) that indicate partial response (PR) or stable disease. One of those compounds discriminated between PR/stable disease and progressive disease.
Additionally, the researchers wrote, “the nano array had the ability to monitor changes in tumor response across therapy, also indicating any lack of further response to therapy.” The success rate in monitoring PR/stable disease was 85%, making it a potentially important tool for clinicians to be able to quickly and easily identify a lack of response to treatment.
Currently, the Response Evaluation Criteria in Solid Tumors (RECIST) is the standard for monitoring whether or not treatment is effective in lung cancer. It is, however, usually performed every two or three cycles or less, so if a treatment is not working the clinician would not know immediately.
“This study offers a proof of concept of the idea that exhaled breath can provide a new modality in monitoring the response to anticancer treatment in patients with advanced lung cancer,” stated the authors. They went on to suggest that monitoring response to treatment in shorter intervals could allow for faster decision-making in cases where the treatment was not working.
The researchers recommended additional studies evaluating the use of VOCs as markers for cancer and for monitoring treatment efficacy or disease progression.
Potential Impact for Labs
With precision medicine being the goal for nearly everyone involved in the healthcare industry, breath analysis to monitor lung cancer treatment could be an important step forward. Because the tests are non-invasive and less expensive than the scans that are currently used to monitor treatment progress, they can be performed more often. More frequent testing means faster decision-making and care that is more personalized and tailored for individual patients.
Clinical pathology laboratories might play an important role in the analyses of breath samples. Many of the tests currently used to monitor lung cancer treatments are processed through radiology departments. However, breath analyses are well-suited to be performed in medical laboratories because gas chromatography and mass spectrometry, the most commonly used methods of breath analyses, are tools available in labs.
Additional Breath Analysis Studies
Diagnostic breath tests are fairly common, such as the Urea breath test for Helicobacter pylori (H. pylori), a gram-negative, microaerophilic bacterium normally found in the stomach that is usually present in patients with chronic gastritis and gastric ulcers.
Nevertheless, breath analysis has continued to be the topic of many studies over the past 20 years, with the last decade seeing a great deal of research. It is particularly studied for its diagnostic potential for conditions ranging from malaria to liver disease to lung cancer. Each study takes healthcare closer to being able to provide precision care to patients.
For example, in 1999, Michael Phillips, MD, Associate Professor, New York Medical College, and Associate Director, St. Vincent’s Medical Center of Richmond, Staten Island, and colleagues, published a study in which they had collected and analyzed breath samples from 108 patients who had abnormal chest x-rays. The researchers reported, “For stage 1 lung cancer, the 22 VOCs [that were examined] had 100% sensitivity and 81.3% specificity.”
Scientists continued to pursue the study of VOCs in relation to diagnostic potential, and in 2004, Wolfram Miekisch, MD, Department of Anaesthesia and Intensive Care Medicine, University Hospital of Rostock, Rostock, Germany, and colleagues, conducted a review of the literature that had been published to date regarding breath analysis and VOCs. In their review, the study authors addressed “analytical procedures, issues concerning biochemistry and exhalation mechanisms of volatile substances, and future developments.” At that point, the authors asserted that “technical problems of sampling and analysis, and a lack of normalization and standardization,” were the reason that the results of different studies were marked by huge variation.
Then, in 2011, Joanna Rudnicka, PhD, an analytical chemist in the Department of Environmental Chemistry and Bioanalytics, Nicolaus Copernicus University, Torun, Poland, and colleagues, published a paper in which they “presented analytical and statistical methods for detection composition of exhaled air [that] could be applied as a potential non-intrusive tool for screening of lung cancer.” In that study, the researchers were able to identify isopropyl alcohol as a compound indicative of lung cancer.
More recently, in a study published in the journal Nature, scientists examined the use of breath analysis to detect ventilator-associated pneumonia (VAP) in patients in the intensive care unit. The researchers, led by Ronny Schnabel, MD, PhD https://nl.linkedin.com/in/ronny-schnabel-13958317/en, an anaesthetist-intensivist at Maastricht University Medical Centre https://www.mumc.nl/en in the Netherlands, concluded that breath analysis is a promising, simple, safe, and non-invasive technique for the rapid diagnosis of VAP.”
Each of these studies brings precision medicine closer to reality. It is clear that medical pathology laboratories will have a critical role to play in performing analyses of breath samples, whether those samples are being used to tailor treatment to individual patients or to diagnose conditions. The tools available in labs, and more importantly, the knowledge that lab personnel possess, form an essential piece of the breath analysis puzzle.