New scientific inquiry originating from the University of Virginia’s Beirne B. Carter Center for Immunology Research and the UVA Comprehensive Cancer Center indicates that significant bouts of respiratory viral illnesses, such as COVID-19 and influenza, might sow the seeds for future lung cancer, potentially accelerating its progression years after the initial sickness. This extensive research also highlights a crucial preventative role for vaccination in mitigating these adverse long-term consequences.
At the forefront of this investigation, Jie Sun, PhD, a distinguished scientist within the UVA School of Medicine, and his team have elucidated how severe respiratory infections can instigate lasting alterations within the lung’s intricate immune cell architecture. These modifications, the study suggests, create an environment conducive to the initiation and advancement of cancerous growths, manifesting months or even years following the acute phase of illness. Consequently, the researchers advocate for heightened vigilance and closer medical observation of individuals recovering from severe COVID-19, influenza, or pneumonia, thereby facilitating the early detection of lung cancer when therapeutic interventions are most effective.
Dr. Sun, who also holds co-director positions at UVA’s Carter Center and within UVA’s Division of Infectious Diseases and International Health, explained the fundamental mechanism: "A severe encounter with COVID-19 or influenza can leave the pulmonary system in a protracted state of heightened inflammation, which subsequently lowers the threshold for cancer to establish itself. The encouraging aspect of these findings is that widespread vaccination demonstrably averts a significant portion of these detrimental cellular changes that otherwise foster lung cancer development."
Respiratory afflictions, including influenza and the novel coronavirus, stand as prominent causes of lung damage. However, the precise pathways through which such acute injuries might contribute to an elevated cancer risk over extended periods have remained a subject of considerable scientific curiosity. To address this knowledge gap, Dr. Sun and his research group undertook a comprehensive examination, assessing the impact of severe pulmonary infections in both controlled laboratory settings utilizing animal models and through the analysis of human patient data.
The results of these experiments were profoundly revealing. Laboratory mice that underwent severe lung infections exhibited a demonstrably higher propensity to develop lung cancer later in life and faced a correspondingly increased mortality rate from the disease. This observation was mirrored in the human data, where individuals who had experienced hospitalization due to COVID-19 demonstrated a statistically significant elevation in lung cancer diagnoses.
The detailed statistical analysis indicated a 1.24-fold increase in the incidence of lung cancer among patients who had required hospitalization for COVID-19. This heightened risk profile persisted irrespective of confounding factors such as smoking history or the presence of pre-existing medical conditions, commonly referred to as comorbidities.
Jeffrey Sturek, MD, PhD, a physician-scientist at UVA who contributed significantly to this collaborative study, underscored the clinical relevance of these findings: "These results carry immediate and substantial implications for how we approach patient monitoring in the aftermath of severe viral respiratory infections. For decades, we have recognized established risk factors for lung cancer, such as tobacco use. This research suggests that severe viral respiratory infections may warrant similar consideration in risk stratification. For instance, in individuals with a substantial smoking history, we routinely recommend proactive surveillance, including regular low-dose CT scans of the lungs, to ensure early detection. Future research may well explore the feasibility and necessity of analogous surveillance protocols following severe viral respiratory illness."
Through meticulous experimentation with laboratory mice, the research team was able to decipher the underlying biological mechanisms linking severe infections to an increased susceptibility to cancer. The study pinpointed critical alterations in specific immune cells, notably neutrophils and macrophages, which are normally integral to the lung’s defense mechanisms.
Following severe infection, a subset of neutrophils exhibited aberrant behavior, contributing to a persistent inflammatory milieu characterized as "pro-tumorigenic," meaning it actively supports and encourages the growth of nascent or existing cancerous cells. Concurrently, the researchers identified significant dysregulation in epithelial cells, the cells that form the inner lining of the lungs and are vital for the gas exchange process within the alveoli, the tiny air sacs responsible for respiration.
The study also presented a beacon of hope concerning preventative strategies. Evidence suggests that prior vaccination against these pathogens may effectively counteract many of the cellular and molecular changes in the lungs that are implicated in cancer development. Vaccines bolster the immune system’s capacity to mount a robust and efficient response to infection, thereby diminishing the severity and duration of the illness.
Crucially, the observed increase in cancer risk was predominantly associated with individuals who had experienced severe cases of COVID-19. In contrast, those who suffered only mild infections did not display this elevated risk; in fact, they showed a slight, albeit statistically non-significant, decrease in lung cancer incidence.
Despite these encouraging findings regarding vaccination, the researchers caution that a substantial population of individuals who have survived severe COVID-19 or other serious respiratory infections may remain at an elevated risk for developing lung cancer in the future.
"Given that tens of millions of individuals globally are contending with persistent pulmonary complications following COVID-19 infection, these findings possess considerable weight for the practical application of clinical care," the researchers articulated in their peer-reviewed publication. "Patients recuperating from severe viral pneumonia, particularly those with a history of smoking, could potentially benefit from enhanced lung cancer surveillance protocols, and the prevention of severe infection through vaccination may offer indirect protective benefits against cancer development."
The research conducted by Dr. Sun and his colleagues aims to equip healthcare professionals with improved tools to identify patients who face a heightened risk of lung cancer subsequent to experiencing severe respiratory infections. The prospect of earlier detection holds the promise of initiating therapeutic interventions at an earlier stage, thereby potentially improving patient prognoses and outcomes. Furthermore, the team believes their insights could pave the way for the development of novel therapeutic strategies designed to prevent or treat lung cancer that arises in the context of prior pulmonary infections.
"Our overarching objective is to empower physicians to discern individuals at increased risk of lung cancer following a severe infection and to devise targeted interventions for the prevention and treatment of post-pneumonia lung cancer," Dr. Sun stated. "We also posit that the benefits of vaccines extend beyond the prevention of acute hospitalization following viral exposure; they may also serve to mitigate the long-term sequelae of severe infection, including the type of immunological scarring that can elevate cancer risk."
The advancement of biomedical research at UVA, particularly in understanding and combating complex diseases, is a cornerstone of the institution’s mission. The Paul and Diane Manning Institute of Biotechnology is dedicated to accelerating groundbreaking research initiatives like Dr. Sun’s work and streamlining the translation of laboratory discoveries into tangible clinical applications and novel therapeutic interventions.
UVA’s Beirne B. Carter Center for Immunology Research (CIC), established through the philanthropic support of Beirne B. Carter and sustained by the Beirne Carter Foundation, continues to be a hub for cutting-edge research. Scientists at the CIC are engaged in exploring a wide spectrum of diseases, including infectious agents, various forms of cancer, cardiovascular ailments, chronic pulmonary conditions, the human microbiome, and autoimmune disorders, with the ultimate goal of developing innovative therapies and cures.
The UVA Comprehensive Cancer Center holds the distinguished recognition as one of only 57 cancer centers in the United States to be designated as "comprehensive" by the National Cancer Institute, a testament to its excellence in patient care and its commitment to advanced cancer research.
The seminal findings of this research have been formally disseminated in the prestigious scientific journal Cell. The collaborative research team comprised Wei Qian, Xiaoqin Wei, Andrew J. Barros, Xiangyu Ye, Haibo Zhang, Qing Yu, Samuel P. Young, Eric V Yeatts, Yury Park, Chaofan Li, Sijie Hao, Gislane Almeida-Santos, Jinyi Tang, Harish Narasimhan, Nicole A Kirk, Valeria Molinary, Ying Li, Li Li, Bimal N. Desai, Peter Chen, Kwon-Sik Park, Anny Xiaobo, Jeffrey M. Sturek, Wei Chen, In Su Cheon, and Jie Sun.
Financial support for this extensive research endeavor was provided by grants from the National Institutes of Health, including specific awards AI147394, AG069264, AI112844, HL170961, AI176171, AG090337, R01HL179312, F31HL170746, T32AI007496, T32CA009109, R01AI155808, and R01HL162783. Additional funding was secured through a UVA Comprehensive Cancer Center Collaborative Grant (U01CA224293), a UVA Pinn Scholar Award, a UVA Shannon Fellowship, a UVA Comprehensive Cancer Center Lung TRT Pilot Grant, an American Lung Association Catalyst Grant (T32GM139787-01), and a UVA Parsons-Weber-Parsons Fellowship.
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