Most Younger Adults With Lung Cancer Diagnosed at Later Stages

Advances have been made in earlier diagnosis and better overall survival among older patients with lung cancer, but younger adults have not experienced the same benefit, according to a new study.

The improvements in patients aged 55-80 are likely associated with the introduction in 2013 of low dose computed tomography lung cancer screening. 

“It was unknown whether young adults diagnosed with lung cancer, who are ineligible for screening, have experienced a similar shift to earlier stages of lung cancer. While previous studies have shown that young adults diagnosed with lung cancer have distinct tumor characteristics and survival compared to older adults diagnosed with lung cancer, no study has examined whether recent improvements in early diagnosis and survival among older adults with lung cancer extend to younger adults diagnosed with lung cancer,” study coauthor Alexandra Potter told this news organization.

The study was presented by Chi-Fu Jeffrey Yang, MD, at a press conference held at the World Conference on Lung Cancer. Yang is a thoracic surgeon at Massachusetts General Hospital, Boston.

The difference might be explained by difference in tumor biology, as younger adults are often diagnosed with more aggressive cancers. Other factors include delayed diagnosis and a lack of early detection strategies for this population. Older patients likely benefited from the onset of lung cancer screening, as well as an increase in non-screening chest CT use in hospital settings, which may lead to more incidental diagnoses, according to Ms. Potter, a research assistant Massachusetts General Hospital and president of the American Lung Cancer Screening Initiative.

Investigators found that about three in four lung cancer diagnoses among adults aged 20-29 were stage IV disease, and only 8% in that group were stage I. “I was surprised” by the high frequency of stage IV cancer, said Ms. Potter. “I would also highlight that there has been no improvement in early diagnosis among patients aged 20-49 during the study period,” she added.

And although it is often assumed that patients diagnosed at a younger age have better survival, the study painted a grim picture: Five-year survival was 10%-15% among patients diagnosed at age 20-49 with stage IV cancer. “More research is needed to better understand the risk factors, diagnosis, treatment, and survival of lung cancer in young adults,” Ms. Potter said.

There are strategies in development, including biomarkers, machine learning analysis of CT scans, and risk prediction models, but none have yet borne fruit. “Once we are able to [identify high-risk young adults], this will allow us to offer lung cancer screening to these young adults who are at high risk for developing lung cancer,” Ms. Potter said.

Study Methodology

The researchers analyzed data from the United States Cancer Statistics (USCS) database and the National Cancer Database (NCDB). They included patients aged 20-79 diagnosed with non–small cell lung cancer (NSCLC) between 2010 and 2018. The study included 1,328 individuals aged 20-29, 5,682 men and women aged 30-39, 39,323 individuals aged 40-49, 202,709 aged 50-59, 410,482 aged 60-69, and 447,366 aged 70-79.

Stage IV diagnoses were most common in the youngest group (76% versus 8% stage I), and steadily declined with age 30-39 (70% versus 10%), age 40-49 (60% versus 14%), 50-59 (52%versus 19%), 60-69 (45% versus 25%), and 70-79 (40% versus 25%; P < .001). The trend reversed among patients aged 80-89, with 45% of patients diagnosed with stage IV cancer, though the rising trend of stage I diagnoses continued at 29%. Between 2010 and 2018, there was a statistically significant increase in stage IV diagnoses among those aged 40-49, and a decrease among those aged 50-59, 60-69, and 70-79.

Five-year overall survival was lowest among patients aged 20-29 at 20%. It was 27%-28% among each 10-year age group up to age 69, then dropped to 24% among those aged 70-79 (P < .001).

The study was limited by a lack of data on disease-free or recurrence-free survival, as well as use of biomarkers or targeted therapy. Ms. Potter has no relevant financial disclosures. The conference was sponsored by the International Association for the Study of Lung Cancer.

This story originally appeared on MDedge.com, part of the Medscape Professional Network.

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