Currently, lung cancer screening using low-density computed tomography (LDCT) scans is available as a tool to screen for lung cancer in individuals at high risk of developing the disease. The tool was first tested in the National Lung Cancer Screening Trial, an eight-year trial that began in 2002 and screened more than 50,000 people. In 2010, when the landmark trial was complete, researchers began analyzing the data and found that LDCT scans were more effective than chest X-rays in identifying lung cancer tumors while the tumors are small enough to remove surgically. LDCT scans resulted in a 20% reduction in lung cancer deaths and led some trial participants to be cured of lung cancer completely.
Today, LDCT scans continue to be the gold standard for lung cancer screening—everyday lung cancer screening saves lives by catching lung cancer early when it is most treatable. However, lung cancer screening hasn’t been as widely adopted into healthcare as other cancer screenings, such as mammography for breast cancer. Only 5% of people at high risk of developing lung cancer (i.e., those who meet the national guidelines for lung cancer screening) get screened annually.
LUNGevity Foundation spoke with Dr. Samir Hanash, Director of the McCombs Institute for the Early Detection and Treatment of Cancer at the MD Anderson Cancer Center, to understand his journey as a researcher to create a blood test that can help people understand their risk of lung cancer and motivate people to get screened for lung cancer. Dr. Hanash was also a recipient of a 2010 LUNGevity Early Detection Award.
LUNGevity Foundation: What first spurred your interest in the early detection of lung cancer?
Dr. Samir Hanash: Early in my career, one of my patients was diagnosed with brain tumors that were too advanced to treat. The patient’s family wanted to know: Why did we wait? Why didn’t we do something more when the cancer was more treatable? That really put the bug in my ear. In those days, most people weren’t thinking much about early detection. But this family got me thinking about looking for features in the blood or the tumor cells that could help us find the cancer earlier.
LF: Why was the early funding for your research so important?
SH: In your career, you start small. The size of my lab was smaller than most kitchens. I was a physician and a scientist with an MD and a PhD. I had responsibilities as a clinician on a full-time basis, and then I did the research on top of that, so all the help I could get was greatly appreciated.
The funding that you get early in your career is so crucial. For me, that funding came from LUNGevity Foundation and the National Cancer Institute. Many others have contributed over the years too. Every contribution counts. The funding encourages you, motivates you, and keeps you going toward whatever goal you have in mind.
LF: How has your career progressed since then?
SH: Initially, I was in Michigan doing my early detection research and seeing patients. Then I moved to Seattle to the Fred Hutchinson Cancer Research Center to lead their efforts on developing molecular tests for cancer. Later, as the early detection and testing area was gaining momentum and we gained strong computing and technology to help us develop testing, I moved to MD Anderson with an ambitious goal—to create a blood test for the early detection of lung cancer.
LF: Tell us more about the research you did at MD Anderson.
SH: We started out with a pencil and paper, making a list of all the possible elements found in a patient’s blood that could be helpful in detecting lung cancer—DNA, RNA, proteins, metabolites, particles released from tumor cells—there were a lot of options. When we surveyed the literature, we found over 10,000 papers with possible biomarker options. So many options would make anyone dizzy. But we had to systematically consider each option.
As we reviewed the literature and narrowed down our choices for biomarkers, we also found two important ways to obtain blood samples from patients before they were diagnosed with lung cancer and after they were diagnosed with early-stage lung cancer. Obtaining these samples was critical so we could understand the key changes to look for when developing a test for lung cancer.
LF: How can you collect blood from patients before they are diagnosed with lung cancer?
SH: We launched a lung cancer screening program at MD Anderson to gain access to blood samples. We enrolled individuals who were eligible for lung cancer screening and willing to participate in the study. This gave us access to their medical histories, blood samples from annual screenings and at diagnosis, and CT image data. We had multiple sites for this study, including Stanford University, University of Southern California, sites in France and Spain, and three sites in China. It was an ambitious undertaking. This study has matured now and most of the individuals have been studied for three or more years.
We were also privileged to have access to blood samples from over a million individuals who were part of population studies from researchers looking at health-related issues. During these studies, blood was collected initially and then the individuals have been followed for approximately five years. Many of those people ended up being diagnosed with lung cancer and we have the blood samples that were collected before they were diagnosed.
LF: Once you have the blood samples what do you do with them?
SH: You can use the blood samples in two different ways. One way is to study the blood to discover new biomarkers that can be used in the blood test. Or you can use the samples to confirm the biomarkers you have already discovered. We did both. We discovered an important protein biomarker, called pro-surfactant protein B, and we also used the samples to confirm our findings from testing we did in mouse models.
LF: Where are you now in the process of developing this blood test?
SH: It has evolved into a panel of four proteins that are tested. The blood test has been tested thoroughly, and now we are working with the Ventures Group at MD Anderson to make the blood test available to people. We hope to have it out to clinicians and patients, likely on a small scale, by the end of 2023.
LF: How will this blood test be used?
SH: It’s important to note that this blood test isn’t intended to replace LDCT lung cancer screening for individuals who are currently eligible. The blood test can tell if someone who has a history of tobacco use that is equivalent to a pack-a-day for ten years or more is at increased risk for lung cancer and may benefit from LDCT screening.
The idea is that along with the usual blood work for cholesterol and blood sugar, a person with a smoking history can also get tested for their risk of lung cancer. If the test results show an increased risk of lung cancer, the person is likely to be motivated to get lung cancer screenings and maybe also make lifestyle choices to reduce their risk.
LF: Can this blood test also be used for patients with low or no tobacco exposure?
SH: We are working to answer that question. The thing is that lung cancer is really different from other cancers and develops in both individuals with and without tobacco exposure. We’re happy that the smoking rates in the US are trending downward. It’s a great step for reducing mortality in lung cancer. It also brings up questions about how we’re going to help patients with former, light, and no tobacco exposure. How do we catch their lung cancers earlier? We’re hopeful that our blood test might be a step in the right direction for all people, to bring us closer to a world where no one dies from lung cancer.
Learn more about recent highlights in lung cancer research with this wrap-up of the 2023 annual meeting of the American Society of Clinical Oncology.