Non-small-cell lung cancer (NSCLC) is a rare form of lung cancer with poorly understood clinical characteristics. According to a new article published in JAMA Oncology, however, there’s a higher likelihood of patients under the age of 50 who are diagnosed with NSCLC having a targetable genomic alteration for which therapies exist.

Non-small-cell lung cancer makes up about 85 percent of diagnosed lung cancers. Its risk factors include first and secondhand exposure to tobacco smoke as well as exposure to radon, asbestos, and other workplace contaminants.

Dr. Geoffrey R. Oxnard, of the Dana-Farber Cancer Institute in Boston, and co-authors set out to explore the relationship between being young at the time of NSCLC diagnosis, the presence of a potentially targetable genomic alteration, and prognosis.

The study looked at 2,237 patients with NSCLC (median age of 62), 712 of whom (32 percent) had the genomic alteration for which approved therapies currently exist — or for whom clinical trial data suggests a strong potential for targeted therapy. Among the patients tested for five genomic alterations, those who were diagnosed under 50 years old were 59 percent more likely to be candidates for treatment. Unexpectedly, lowest overall median survival rates were in patients younger than 40 (18.2 months) and patients older than 70 (13.6 months).

Of the entire group of patients, 87 percent had historically confirmed adenocarcinoma (cancer that originates in the cells lining the alveoli), 12 percent had unspecified NSCLC, and 1 percent had squamous histologic findings (cancer that begins in the flat squamous cells). Sixty-three percent of the participants had either stage IIIB or stage IV cancer, and about 27 percent of the patients had never smoked.

The study authors noted limitations of the study, including the historical and retrospective nature of the data (the patients all underwent genotyping between 2002 and 2014), as well as limited comprehensive data on individual patient treatment methods.

“Despite the aforementioned limitations, the findings of this study expand current understanding of the genetics and biology of lung cancer in young patients,” the authors wrote. “These patients possess a uniquely high incidence of targetable genomic alterations paired with an unexpectedly poor prognosis. This combination of opportunity and risk defines the treatment of NSCLC in young patients and requires unique therapeutic and research strategies.”

Source: Sacher A, Dahlberg S, Heng J, Mach S, Janne P, Oxnard G. Association Between Younger Age and Targetable Genomic Alterations and Prognosis in Non-Small-Cell Lung Cancer. JAMA Oncology. 2015.