A new study finds that diagnosing early-stage lung cancer with low-dose computed tomography (CT) screening significantly improves the survival rate of cancer patients over a 20-year period.
Presenting at the 2022 Radiological Society of North America (RSNA) Annual Meeting, Mount Sinai Health System researchers detailed the findings of the international study, which they say "are the latest to demonstrate the importance of routine and early screening in detecting cancers when they are small enough to be cured by surgical removal."
The U.S. Preventive Services Task Force (USPSTF) recommends annual lung cancer screening with low-dose CT in adults ages 50-80 years who have a 20 pack-year smoking history, which equals at least a pack a day for 20 years, and who currently smoke or have quit within the past 15 years, the researchers noted. This study tracked the 20-year survival rate of 1,285 patients who were screened in the International Early Lung Cancer Action Program (I-ELCAP) and who were later diagnosed with early-stage lung cancer.
While the overall survival of the participants was 80 percent, the survival rate for the 139 participants with non-solid cancerous lung nodules and the 155 participants with nodules that had a partly solid consistency was 100 percent. For the 991 participants with solid nodules, the survival rate was 73 percent. For participants with Stage IA cancers that measured 10 mm or less, the 20-year survival rate was 92 percent.
The results showed that patients diagnosed with lung cancer at an early stage via CT screening have a 20-year survival rate of 80 percent. The average 5-year survival rate for all lung cancer patients is 18.6 percent, the researchers wrote, because only 16 percent of lung cancers are diagnosed at an early stage. More than half of people with lung cancer die within 1 year of being diagnosed, making it the leading cause of cancer deaths. By the time symptoms appear, it is often too late, the investigators noted.
"While treatments of more advanced cancers with targeted therapy and immunotherapy have come a long way, the best tool against lung cancer deaths is early diagnosis through low-dose CT screening before symptoms occur," according to the study authors.
The purpose of lung cancer screening is to "find lung cancer in its earliest stage and to treat it with the intent to cure it," says the study's lead author, Claudia Henschke, MD, PhD, Professor of Diagnostic, Molecular and Interventional Radiology and Director of the Early Lung and Cardiac Action Program at the Icahn School of Medicine at Mount Sinai.
Currently, it is well-established that screening can find lung cancer earlier and that early-stage lung cancer is more curable than late stage, "but there have been questions regarding how much better," said Henschke, adding that the quantitative issue is critical to understand the benefit.
"It is not enough to simply say that it is more curable; the question that really needs to be answered is how much better. The way to answer that is to follow those lung cancers found by screening and to see how those that are treated do over a long follow-up period, where we have sufficient follow up to determine that the cancer will not kill them and that they have been cured of it," she continued. "When we published this data almost 10 years ago, there were concerns expressed that we did not have sufficient follow-up, now we believe there should no longer be any question."
The dramatic increase in long-term survival can be fully attributed to finding the cancers early through lung cancer screening, reinforcing the USPSTF recommendations that screening is beneficial and that screening should be done annually to achieve this type of benefit, Henschke noted.
In terms of what these findings could mean for the way cancer care and oncology teams manage the diagnosis and subsequent treatment of early-stage lung cancer, Henschke said the results should first and foremost lead to an enhanced approach to making individuals aware of and enrolled in screening programs, adding that less than 15 percent of those eligible for screening for CMS coverage are actually being screened.
"Hopefully, knowledge of how successful screening can be to cure early-stage lung cancer will help toward this goal, which is now endorsed by all major societies. Nothing in cancer care has the potential to cure more lives from cancer than increasing the number of people enrolling in lung cancer screening programs and [this] fully aligns with the mission of the Cancer Moonshot."
Mark McGraw is a contributing writer.