Often there are no symptoms of early stage lung cancer, which is why it is often diagnosed at a late stage when surgery to remove a tumor is no longer an option. The lack of a standardized early stage lung screening test is one of the most critical deficiencies in healthcare.
Typically only high risk patients are approved for a chest CT
Lung cancer screening tests, depending on the US state or Canadian province, are usually only approved for a select group of high risk patients, which primarily depends on age and a history of heavy smoking. The obvious problems is that approximately 15 to 20% of lung cancer patients are non-smokers and so this group account will account for over 20,000 deaths in the US each year. See the news release below:
September 14, 2020 British Columbians at high risk of lung cancer will soon be able to receive early detection screening, thanks to the provincial government’s investment in a new lung cancer screening program – the first of its kind in Canada.
The target population for this new cancer screening program will be adults aged 55 to 74 who smoke or have a heavy smoking history. It’s expected the first participants could be receiving scans by spring 2022.
A regular chest CT emits the radiation of 70 chest X-rays. Whereas "Low Dose" chest screening CTs emit on average the equivalent of 14 chest X-rays.
Early-stage cancers are often small, and thus hard to visualize.
Even when small masses, commonly referred to as nodules are detected in the lungs, most of the time they are not removed or biopsied. Many mall nodules are benign, whereas larger masses are typically cancerous. In this case, CTs are often repeated over time to see if the nodule increases in size.
"Because of the survival rate can change from one in 10 people surviving ... to seven or more surviving five years by detecting it early, it could have a huge impact on survival from lung cancer," Dr. Miller said.
Despite a few new drugs having been approved in the last couple years, the survival rate for lung cancer is abysmal. Historically only 1 in 10 lung cancer patients lived 5 or more years and it is still less than 2 in 10. Most lung cancer patients die within a year of being diagnosed.
Patients simply have to cough up and then have their sputum placed on the test strip. A few steps and 15 minutes later the results are available. Before the patient leaves the office, their doctor will let them know if further evaluation is needed, such as an Xray or lung CT scan. Physicians consider other factors, however because lung cancer often presents with no symptoms, this test for the altered sugar that is only produced by precancerous or cancerous cells may become an indispensable tool.
The clinical trial shown below had an accuracy of 90.7% sensitivity (165/182) . The specificity was 81% (94/116) and thus the "presumed" false positive rate of 19% or 22/116 (100% less 81% = 19% false positive rate).
15 of these patients with "presumed" false positive results were found to have lung cancer in a follow up evaluation.
The ultimate goal of screening - FIND IT EARLY