Results from a new study presented at the annual meeting of the American Association for Cancer Research (AACR) in San Diego, April 17 – 22, 2026, showed that lifestyle patterns and dietary exposures could play a role in tumor mutational burden among young adults with lung cancer.[1]
The results, presented by the Addario Lung Cancer Medical Institute (ALCMI), and GO2 for Lung Cancer (GO2), were drawn from the ongoing Epidemiology of Young Lung Cancer study and may help uncover modifiable risk factors in a population where lifestyle behaviors traditionally associated with lung cancer, such as smoking, fail to explain disease onset.
This project is conducted by researchers from California Northstate University College of Medicine, the Dana-Farber Cancer Institute, The Ohio State University Comprehensive Cancer Center, and USC Norris Comprehensive Cancer Center, part of Keck Medicine of USC. The work is supported by AstraZeneca, the Beth Longwell Foundation, Genentech, GO2 for Lung Cancer, and Upstage Lung Cancer.
There is growing concern that lung cancer is biologically distinct in adults under 40, with 84% of patients carrying targetable mutations. These historically younger patients are predominantly female and never-smokers, which raises questions about other potential environmental contributors.
Study design
The new analysis examined data from 187 patients (157 females; 84%) in the Epidemiology of Young Lung Cancer (YLC) study (NCT04640259) to assess dietary patterns and food exposures in relation to mutation subtypes. The researchers used mutation-based grouping by shared biological mechanisms, including the EGFR Pathway (EGFR+ERBB2), Fusion Positive (ALK+ROS1+RET+NTRK), and Other/Mixed Mutations (including MET exon 14 skipping, TP53, KRAS, BRAF, and additional alterations). Of these, 166 patients (138 females; 83.1%) completed validated food frequency questionnaires, which used the Healthy Eating Index-2015 (HEI-2015) and were compared to U.S. reference values from NHANES. [2]
The findings demonstrate that although patients with EGFR and fusion mutations reported better overall diet quality than the U.S. population average, with higher intake of fruits, vegetables, and whole grains, reflected by higher HEI-2015 component scores (out of 5) for total vegetables (4.2 vs. 3.5), fruits (3.3 vs. 2.5), and whole grains (3.9 vs. 2.6). However, while a diet that includes fruits, vegetables, and whole grains is considered to offer good health benefits, a number if studies suggest that whole foods often contain elevated to high pesticide/herbicide contaminants or residue.* In turn, researchers believe that these contaminants may offset some of the general health benefits (such as lower all-cause mortality) typically associated with a plant-rich diet, and represent an overlooked environmental risk factor and a greater exposure potential, warranting further investigation into the role of pesticide-contaminated fruits/vegetables/whole grains in the changing prevalence of lung cancer. [1][2]
The study results also point to unexpected associations with tobacco. In the fusion pathway group (ALK, ROS1, RET, NTRK), 55.6% were never-smokers, challenging conventional links between these mutations and tobacco exposure. Conversely, one-third of EGFR pathway patients reported a smoking history, higher than anticipated.
Finally, the researchers point to a potential connection to oral contraceptives. Oral contraceptive use was consistently elevated across all biological pathway groups (between 75% – 100%). Although most patients reported 1-5 years of use, the median duration was 10 years, driven by a subset of long-term users. This matters because the pesticides can act as endocrine disruptors that interact with estrogen receptors seen in the lung cancers most prevalent in the young lung cancer population.
More research needed
The study team notes that further research is needed to clarify how dietary pesticide exposure interacts with genetic pathways and whether reducing exposure could lower risk.
“These findings demonstrate that there is still so much to learn about this terrible disease, particularly as it occurs in young people,” said ALCMI Executive Director and COO Richard Erwin.
“Our hope is that this is just the beginning of this research and that others will join us in exploring how and why lung cancer is presenting in the younger patient population,” Erwin added.
“This work represents a critical step toward identifying modifiable environmental factors that may contribute to lung cancer in younger adults,” noted Jorge J. Nieva, MD, a thoracic oncologist with USC Norris Comprehensive Cancer Center.
“Our hope is that these insights can guide both public health recommendations and future research into prevention,” Nieva said.
“Too many young people diagnosed with lung cancer are left asking, ‘how did this happen?’ especially when they have no known risk factors,” explained Chief Patient Officer and Co-Interim CEO of GO2 for Lung Cancer Danielle Hicks.
“This research reflects what patients have long suspected. There may be risk factors beyond their control. It’s a critical step toward understanding risk, improving early detection, and giving patients clearer answers,” Hicks said.
These findings would not be possible without the vision of ALCMI Co-Founder Bonnie J. Addario, who passed away in 2025. She long suspected an unknown environmental link could be contributing to this disease and was steadfast in her determination to search for answers for lung cancer patients.
“While more research is needed to confirm these findings, this is the first clear evidence that lung cancer in younger patients may develop through a different biological pathway,” said Tony Addario, ALCMI co-founder and husband of the late Bonnie Addario.
“This discovery is both scientific and deeply personal. Bonnie’s vision has guided this research from the very beginning, and her legacy continues in the hope we bring to every person facing lung cancer, and in the lives we may one day prevent from ever being touched by it,” he concluded.
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Note:* Conventionally grown fruits and vegetables are the main source of exposure to pesticide residues for the general population. According to the Environmental Working Group (EWG), which tracks the most contaminated produce annually, in 2026, the most contaminated fruit and vegetables include strawberries, spinach, kale/collard/mustard greens, grapes, peaches, pears, nectarines, apples, bell and hot peppers, cherries, blueberries, and blackberries. One emerging concern is that over 60% of samples tested by the Environmental Working Group in 2026 now contain PFAS (known as forever chemicals), which are linked to various cancers and liver damage. Furthermore, while whole grains are recommended to lower cancer risk, they are increasingly contaminated with aflatoxins (molds), which are classified as human carcinogens.
Clinical trials
Epidemiology of Young Lung Cancer – Survey (EoYLC) – ClinicalTrials.gov ID NCT04640259
Reference
[1] Gorbatov SD, Bittoni MA, Wu AH, Harper A, Virginia K, Florez N, Gitlitz BJ, Jorge J. Nieva JJ. Dietary patterns in young lung cancer: mutation-specific environmental associations. In: Proceedings of the 117th Annual Meeting of the American Association for Cancer Research; 2026 April 17-22; San Diego, CA.: AACR; 2026. Abstract nr: 5039 / 12. [Abstract]=
[2] Sandoval-Insausti H, Chiu YH, Wang YX, Hart JE, Bhupathiraju SN, Mínguez-Alarcón L, Ding M, Willett WC, Laden F, Chavarro JE. Intake of fruits and vegetables according to pesticide residue status in relation to all-cause and disease-specific mortality: Results from three prospective cohort studies. Environ Int. 2022 Jan 15;159:107024. doi: 10.1016/j.envint.2021.107024. Epub 2021 Dec 8. PMID: 34894487; PMCID: PMC8771456.
Featured image: © 2020 – 2026 Nathan Dumlao on Unsplash. Used with permission.
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