麻豆传媒

VIENNA -- Younger adults (ages under 50) with non-small cell lung cancer (NSCLC) were significantly more likely than older adults to be diagnosed with advanced disease, a researcher said here.

In 2018, 5 years after the U.S. Preventive Services Task Force recommended low-dose CT lung cancer screening (LCS) for people over age 55 -- lowered to -- with certain risk factors, 64% of patients ages 20-49 with NSCLC were diagnosed with stage IV disease versus 43% ages 50-79, for an absolute difference of 21%, reported Chi-Fu Jeffrey Yang, MD, of Massachusetts General Hospital in Boston.

That absolute difference was substantially greater than the 13% difference observed in 2010, when 60% of younger patients were diagnosed with stage IV disease versus 47% of older patients, he said in a presentation at the World Conference on Lung Cancer (WCLC).

"Different tumor biology, delays in diagnosis, and the absence of methods to facilitate early detection of lung cancer among young adults likely contributes to the high rate of stage IV disease diagnosed in this population," said Yang at a WCLC press briefing.

However, WCLC discussant Anand Devaraj, MD, of Royal Brompton Hospital, Imperial College in London, cautioned that "it's not possible to determine whether this stage shift is directly attributable to screening -- there may be other factors involved."

In 2021, the task force revised its LCS recommendation for those ages 50-80 who have a 20 pack-year smoking history and currently smoke, or those that have quit within the past 15 years. The recommendation also states that "Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery."

"What this data [from Yang's group] prompted me to think about is the challenge we all face ... which is how to identify high-risk participants in groups that cannot be easily accessed, and that is not just younger patients, but also older patients without sufficient risk factors based on current risk models," Devaraj said.

Yang and colleagues used the Surveillance Epidemiology End Results (SEER) database and the National Cancer Database to identify patients, ages 20-79, diagnosed with NSCLC from 2010-2018. During that period 1,038, 5,682, and 39,323 individuals ages 20-29, 30-39, and 40-49, respectively, were diagnosed with NSCLC.

The authors observed that with increasing age, the percentage of patients diagnosed with stage I NSCLC rose over time, while the percentage of patients diagnosed with stage IV cancer decreased. Specifically, they found that among younger adults, 8% of patients (ages 20-29) were diagnosed with stage I disease, while 76% were diagnosed with stage IV disease. The percentage of patients in the 30-39 and 40-49 age groups diagnosed with stage I disease slightly increased to 10% and 14%, respectively, while the percentage of patients diagnosed with stage IV disease in those age groups declined, but was still high at 70% and 60%, respectively.

In contrast, 29% of patients (ages 70-79) were diagnosed with stage I disease and 40% were diagnosed with stage IV disease.

Yang and his colleagues also looked at survival data and found that while there was no improvement in early diagnosis among young adults, median overall survival (OS) of young adults diagnosed with NSCLC did increase by 14 months from 2010-2018, largely due to improvements in survival for patients with advanced disease.

"Notably, these improvements in median overall survival appear to align with the NCCN [] recommendation for genetic testing for EGFR and ALK mutations in 2012, as well as the FDA's of immunotherapies in 2015," Yang said.

However, Yang and colleagues found that the youngest patients (ages 20-29) diagnosed with NSCLC had the lowest 5-year survival rates at 20% versus 5-year OS rates ranging from 24% for older patients (ages 70-79) to 28% for middle-age patients (40-49). Moreover, 5-year OS for patients diagnosed with stage IV disease was particularly low in all younger age groups (11%, 15%, and 10% for patients in the 20-29, 30-39, and 40-49 age groups, respectively).

Study limitations included that fact that it did not include data regarding disease-free or recurrence-free survival, tumor biomarkers, the use of targeted therapy, or the time from initiation presentation to lung cancer diagnosis.

Yang noted that "these improvements in median survival observed in young adults diagnosed with lung cancer are encouraging," but his group stressed that strategies to increase the early detection of lung cancer among younger patients, who are generally ineligible for LCS, are "urgently needed."

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