Screening presents a dilemma for lung and cancer specialists: Only about four percent of abnormal spots found on patients’ lungs during preventative CT screening turn out to be cancer, yet lung cancer is one of the deadliest types of cancer and usually progresses rapidly, so catching it early is particularly important.
C. Matthew Kinsey, M.D., M.P.H., UVM Assistant Professor of Medicine and pulmonary and critical care specialist. (Photo: LCOM Design & Photography)
Screening presents a dilemma for lung and cancer specialists: Only about four percent of abnormal spots found on patients’ lungs during preventative CT screening turn out to be cancer, yet lung cancer is one of the deadliest types of cancer and usually progresses rapidly, so catching it early is particularly important.
Clinicians don’t want to put the patient through a biopsy for a tiny nodule that is benign, but they don’t want to wait to take action in case it is cancerous.
C. Matthew Kinsey, M.D., M.P.H., assistant professor of medicine and a pulmonologist at the Larner College of Medicine and University of Vermont Medical Center, hopes to alleviate some of the guesswork by finding a way to measure the likelihood of cancer in these cases. The National Institutes of Health recently funded Kinsey’s ongoing study of a CT scan biomarker for lung cancer with a five-year $800,000 K23 Mentored Patient-Oriented Research Career Development Award grant from the National Institutes of Health (NIH).
CT, or computerized tomography, screening for lung cancer is recommended for patients aged 55 to 78 with a smoking history of 30-plus years and who have quit less than 15 years prior. This preventative scan leads to frequent “false-positive” findings of suspicious spots, usually around two centimeters. Kinsey is performing the research with his mentor, Professor of Medicine Jason Bates, Ph.D., as well as Jeffrey Klein, M.D., A. Bradley Soule and John P. Tampas Green and Gold professor of radiology, and Brigham and Women’s Hospital collaborators George Washko, M.D., a pulmonary and critical care specialist, and Raul San José Estépar, Ph.D., from the Department of Radiology.
A biopsy will determine cancer, but it’s an invasive procedure that patients shouldn’t have to undergo unnecessarily, Kinsey says. It commonly involves inserting a needle through the chest to take a sample of the nodule and carries risks, including that of a pneumothorax – a collapsed lung – which can transform a healthy person into a hospital patient.
“It is critical to determine if a lesion in the chest is cancer but we need to try to do it in a way that minimizes risks to patients” he says.
Even when a biopsy finds no cancer, a patient has suffered the stress of the process and the worry caused by hearing such scary news.
“It negatively affects their quality of life,” says Kinsey.
As an alternative, doctors can opt to follow up with subsequent scans and keep an eye on the suspicious spot. The risk is that the tiny nodule may grow and potentially, Kinsey says, showing CT scans as illustration.
Researchers have examined the nodules themselves, trying to detect some indication of cancer in their shape or tentacles extending from the site. Those efforts didn’t quantify the risk with any certainty, though, depending on more qualitative analysis by radiologists, Kinsey says.
His is the first study to focus on the area around the abnormality and the factors of that geography that relate to cancer. If a nodule appears in a section of the lung that also shows a lot of emphysema – associated with a higher risk of lung cancer – it is more likely to be cancer. Another key indicator is blood vessel density, “because cancers need a lot of blood flow,” Kinsey says. With a dark spot in an area thick with blood vessels, the chance of cancer is greater.
“We know that where the nodule occurs and the company it keeps is important,” Kinsey says.
His work will develop a way to measure those indicators and give a “score” of cancer risk – a percentage that a particular abnormality is cancer. He’s using data from 25,000 patients who had CT scans for the National Lung Screening Trial, the NIHs large-scale study of smoking risk, and another 10,000 smokers scanned as part of a gene study for chronic obstructive pulmonary disease (COPD).
Even small improvement in the ability to predict cancer, Kinsey says, could potentially result in significant differences in care for patients.