Lung cancer screening and early detection were major topics of discussion at the World Conference on Lung Cancer (WCLC), held in San Diego from September 7-10, and the European Society for Medical Oncology (ESMO) conference in Barcelona from September 13-17. This fourth and final blog in our series of updates summarizes highlights from these discussions.
You can read the other update blogs from these fall science meetings:
- Metastatic NSCLC Highlights
- Small Cell Lung Cancer Highlights
- Early-Stage and Locally Advanced NSCLC
Cancer screening involves tests that can detect early-stage cancer when curative treatment is possible. Lung cancer screening involves using low-density computed tomography (LDCT) to take multiple pictures of what’s happening inside the lungs, just like an X-ray.
In the US, LDCT scans are only offered to individuals who are considered to be at high risk for developing lung cancer:
- Those who are between the ages of 50 and 80, and
- Currently use tobacco, or have quit using tobacco within the past 15 years, and
- Have a 20 pack-year of tobacco exposure
Typically, when a person gets an LDCT, they are also offered tools to help quit tobacco (often referred to as tobacco cessation programs).
Redefining Who Should Be Screened for Lung Cancer
An entire plenary session at WCLC 2024 was dedicated to the topic of lung cancer in people without tobacco exposure, also known as lung cancer in people who have never smoked, highlighting that this topic is top-of-mind for researchers.
If taken as a separate disease, lung cancer in people who have never smoked (LCINS) is the 5th-leading cause of cancer-related deaths in the world. Leading causes of LCINS are air pollution, occupational exposure to cancer-causing chemicals, radon, and the genetics of the person. LCINS has a distinct biology as compared to tobacco-associated lung cancer.
Though lung cancer screening is not offered to people who do not meet the screening criteria, several studies emerging from Asia suggest that risk factors such as family history of lung cancer may need to be included in screening guidelines. In the US, the Female Asian Nonsmoker Screening Study is looking at whether lung cancer screening offered to Asian women without a history of tobacco exposure can detect LCINS.
Air pollution, specifically very fine particles called PM2.5 (or particulate matter 2.5), can be breathed in easily. PM2.5 is known to cause LCINS, particularly lung adenocarcinoma (a type of non-small cell lung cancer) with EGFR mutations.
In addition, the lung inflammation caused by PM2.5 increases levels of interleukin-1 beta, which seems to play a role in the development of pollution-associated lung cancer. This has opened up new areas of research testing drugs that block interleukin-1 beta as a strategy to both prevent and stop the development of LCINS. It also opens up the question of how we can offer lung cancer screening to individuals living in high-pollution areas.
No lung cancer conference is now complete without a discussion about the connection between climate change and air pollution. In the United States, there has been an increase in wildfires because of the climate change crisis. Wildfires are a source of PM2.5 and studies are ongoing to test if lung cancer screening should be offered to individuals living in high-risk areas.
How can we integrate PM2.5 levels into lung cancer screening? Researchers in Canada have developed a simple, user-friendly, PM2.5 assessment tool that quantifies long-term PM2.5 exposure. This tool will be available to the public shortly.
Improving LDCT Screening
Several studies discussed how artificial intelligence (AI) can improve our ability to detect lung cancer using LDCT scans. AI-based tools that can analyze already available CT scan data, such as Sybil developed in the United States, are helping us better predict future risk of developing lung cancer and identify who needs to be monitored more vigilantly. Other AI-based tools such as the one described in the European 4-IN-THE-LUNG-RUN Lung Cancer Screening Trial are aimed at helping read the LDCT scans more efficiently.
Other approaches, such as blood-based tests, are being developed to complement LDCT scans and to help decide whether a lung nodule requires more aggressive follow up.
Improving Access to LDCT Screening
In the United States, only 4.5% of people eligible to receive LDCT scans receive them. A recent study suggests that a mobile phone-based intervention may help in increasing access to both tobacco cessation and to lung cancer screening. While the study participants needed to own a mobile phone, have health insurance, and also have a primary care provider from whom they receive regular care, it still highlights that we need innovative approaches to increase access to lung cancer screening.
Moving Beyond LDCT Scans
An area of intense investigation is the development of simpler tests to detect lung cancer. Blood-based tests have gained a lot of traction in this space because of their reliance on a simple blood draw that can be done at a doctor’s visit. Tests that detect either changes or methylation patterns in a cell’s DNA or specific proteins in the blood have already been developed. New data suggests that blood tests that detect both proteins and methylation patterns on DNA may be more sensitive at detecting early-stage cancer. This is important to keep in mind because a test is able to separate early-stage cancer from advanced-stage cancer is what will be important in saving lives.
Dr. Jaclyn LoPiccolo shared insights into lung cancer in people with no tobacco exposure during LUNGevity’s recent International Lung Cancer Survivorship Conference (ILCSC). You can watch the video by registering here. This concludes our last blog in this series.