Dr. Backhus Presents Webinar on Lung Cancer Surveillance
at the National Cancer Institute

by Stanford CT Surgery Marketing Team
April 15, 2025

On March 18, 2025, Leah Backhus, MD, MPH, Professor with the Stanford Department of Cardiothoracic Surgery, provided a compelling webinar on surveillance of lung cancer after treatment to members and supporters of the National Cancer Institute. Her talk titled, “Bringing Precision Oncology to Lung Cancer Surveillance,” was part of the Director Series, presented by the institute’s Division of Cancer Control and Population Sciences. During the hour, she reviewed her own research and that of others to offer a significant summary of surveillance after lung cancer treatment, presenting the current state of surveillance, roadblocks, and next steps in future surveillance research.

“Historically, there has been one-size-fits-all for non-small cell lung cancer surveillance. After treatment, patients received a CT scan every six months. It is more complex today and varies by the patient's stage, presentation, and if they have received radiation,” Dr. Backhus said.

Surveilling with a CT scan or a chest X-ray in the first follow-up visit

Early in her research, Dr. Backhus undertook a research study titled, “Predictors of Imaging Surveillance for Surgically Treated Early Stage Lung Cancer” to understand if we are surveilling lung cancer patients optimally. Her study focused on the post-six-month imaging scan and found that the first imaging was a chest x-ray 60% of the time; only 25% of patients received a CT scan.

She also discussed whether a lack of a follow-up visit might be playing into a lower than ideal surveillance level. To consider this, she turned to the SEER-Medicare dataset, which captures 1.7 million outpatient visits and 217,000 tests. The answer was clearly no since she and her team found that 98% of lung cancer patients received an outpatient clinic visit within the first four to eight months.

Learning which provider most often performs surveillance

As part of her research on lung cancer surveillance, Dr. Backhus also delved into precisely who was performing the surveillance. She learned that only 40% of patients see their cardiothoracic surgeon in the first seven to 12 months post-surgery. She considered that patients may not have the capacity to see their surgeon or oncologist and may more likely be seeing their primary care physician for surveillance. She discovered that surveillance varies by provider type, finding that when patients saw a surgeon, pulmonologist, or primary care provider, they were more likely to receive a chest X-ray rather than a CT scan–something radiation oncologists and medical oncologists were more apt to do.

Gauging provider interest in lung cancer surveillance

These findings led her to ask, ‘Do providers think surveillance is important?’ She quoted a 1995 Society of Thoracic Surgeons (STS) survey of cardiothoracic surgeons that found only 44% believed in a survival benefit for surveillance for stage 1 non-small cell lung cancer patients, and only 25% felt there was sufficient evidence to support its use.

“My colleagues and I repeated the survey with the STS in 2016 and found that the view on surveillance is better but not overwhelming. For example, only 66% thought there was a survival benefit for stage 1 patients, and that dropped to 21% for stage 2 and 3 lung cancer patients. This indicated little change in surgeons’ beliefs supporting surveillance,” she said. 

Dr. Backhus also completed a meta-analysis of nine studies on the survival benefit of lung cancer surveillance and found a general trend favoring surveillance. Still, it was just that: a trend that was not statistically significant. Dr. Backhus stated that we have poor rates of surveillance after lung cancer treatment and only retrospective studies with crude outcomes limited to survival to understand why. There is no precise data regarding indications for testing in the research.

The future of lung cancer surveillance research

She believes that in order to learn more about lung cancer surveillance numbers and quality we need a larger series of more temporal trends, cost data, and granular data. In an attempt to achieve this, Dr. Backhus and her colleagues are currently undergoing a study called Imaging Surveillance After Lung Cancer Treatment (iSALT), which uses robust data sources from Veteran Affairs.

“We have access to a large database of oncology data, cancer variables, rich clinical data, and an expansive repository of radiology text reports in raw form and clinician notes. Instead of relying solely on large language models and machine learning, which can lose accuracy, we use a semi-automated abstraction that has completely revolutionized how we achieve accurate and granular data,” Dr. Backhus said. This abstraction method allows iSALT researchers to drill down and see if surveillance was given, what type of scan, and other compelling details.

The next step in lung cancer surveillance is to consider whether or not there are roadmaps to follow from other cancer disciplines, provide patients with more risk stratification, explore new data point biomarkers for treatment and outcomes, such as ctDNA, and overcome a possible knowledge gap among primary care providers. A goal of surveillance also must be to balance cost and quality of life for patients.

“The grand finale for iSALT is prospective modeling. It is difficult to do in this space, so if we can at least get more data toward that randomization, it will be a success,” she concluded.

Dr. Backhus is the Thelma and Henry Doelger Professor of Cardiovascular Surgery at Stanford and Chief of Thoracic Surgery at the VA Palo Alto. She is Co-Director of the Thoracic Surgery Clinical Research Program at Stanford, and has grant funding through the VA Administration and NIH. Her current research interests are imaging surveillance following lung cancer treatment and cancer survivorship.