One Breath May Show Signs of Lung Cancer

New experimental breath test may detect lung cancer and distinguish between stages of disease

(RxWiki News) Cancer screening can be costly and invasive, and it often catches the disease in advanced stages. What if cancer screening was as simple as blowing up a balloon?

A recent study found that a test could tell whether or not a person had lung cancer based on particles in a person’s exhaled breath.

The researchers discovered that the test also distinguished between early and advanced stages of lung cancer.

"Discuss cancer screening with your doctor."

The lead author of this study was Fred R. Hirsch, MD, PhD, from the CU Cancer Center in Aurora, Colorado and the Division of Medical Oncology at the University of Colorado School of Medicine in Denver, Colorado.

The study population consisted of 358 people from Israel, Colorado and Florida who provided breath samples that were analyzed for volatile organic compounds indicative of lung cancer.

Volatile organic compounds are gases that come from various solids and liquids that contain a variety of chemicals — some toxic and some not — that can cause irritation and other adverse health effects.

The researchers wanted to see if a new noninvasive breath test could tell if a person had lung cancer, and if so, which stage the disease was at.

A subanalysis with 80 lung cancer patients and 31 control subjects with chronic obstructive pulmonary disease (COPD) was also conducted to see if the test could distinguish the two conditions. COPD is one of the most common lung diseases where it becomes progressively harder to breathe over time.

The test involved a person blowing up a balloon, and then the researchers attached the balloon to a hypersensitive nanoparticle sensor. The particles in the person’s exhaled breath get trapped and analyzed for any volatile organic compounds.

The findings showed that 213 people had lung cancer and 145 people did not have lung cancer.

Among those with lung cancer, the test was able to determine that 62 people were in the early stages of the disease and 143 were at an advanced stage.

The subanalysis between the lung cancer patients and the COPD patients was able to detect whether or not a person had COPD or early stage lung cancer 85 percent of the time, and whether or not a person had COPD or advanced stage lung cancer 82 percent of the time.

The researchers also discovered that the breath test was able to distinguish the difference between early and advanced lung cancer 79 percent of the time in the subanalysis.

"The metabolism of lung cancer patients is different than the metabolism of healthy people," explained Dr. Hirsch, “And it is these differences in metabolism that can define the signatures of healthy breath, COPD or lung cancer.”

Recent lung cancer screening guidelines set by the U.S. Preventive Services Task Force say the use of low-dose compute tomography (noninvasive x-rays showing detailed pictures of inside the body) has the potential to reduce death from disease by 20 percent. Due to these guidelines, Dr. Hirsch believes that there is a need for new noninvasive tools to screen for and diagnose lung cancer. These guidelines only apply to high-risk patients who are high-risk because of current or former smoking habits.

Unfortunately, the high sensitivity of the breath test allows for more false positives where many of the nodules (small bumps that can grow into tumors if cancerous) found are benign. Nodules and tumors that are cancerous are malignant and ones that are noncancerous are benign.

"You detect many, many nodules in those screenings and unfortunately, around 90 percent of them are benign. So you need to find out how to better distinguish malignant from benign modules. The goal of this tool is to use breath biomarkers to distinguish malignant from benign screen-detected nodules," Dr. Hirsch said.

The findings also revealed that the breath test’s potential uses go beyond screening and diagnosis.

The test could possibly help measure the change in a patient’s levels of volatile organic compounds over a period of time, thus indicating how well a patient is responding to treatment, and whether or not they should stay with their current drug regimen or try other treatment options.

The study was limited because the study population was small and at high risk for lung cancer, so the findings may not be generalizeable to other groups of people. In addition, this study is the first of its kind and was not peer reviewed.

This study was presented on May 31 at the 50th Annual Meeting of the American Society for Clinical Oncology.

Review Date: 
May 31, 2014