Scientists from research center Applied Medicine (CIMA) and the Clínica Universidad de Navarra have described a biomarker that could guide the early diagnosis and prognosis of lung cancer. The results have been published in the Journal of the National Cancer Institute.

Until now it was known that a component of innate immunity, the complement system, is activated in lung tumor cells and promotes disease progression. But neither the mechanisms nor the proteins generated after activation were known. "We have detected that a protein of this system, called C4d, is upregulated in lung cancer patients. Specifically, our work shows that the presence of C4d is associated with increased mortality and that its levels are reduced after surgical removal of the tumor. Furthermore, this protein increases the risk of being suffering from the disease in asymptomatic people, so it could become a biomarker for the early detection and treatment of lung cancer," explains Daniel Ajona, lead author of work, directed by Dr. Luis Montuenga and Dr. Rubén Pío, researchers at the area Oncology Department at CIMA, at partnership with several Departments from Clínica Universidad de Navarra.

The work has been carried out with samples from more than 300 lung cancer patients and more than 400 healthy individuals or individuals with non-malignant respiratory pathologies. Scientists from Vanderbilt University Medical Center (United States) and the Hospital General Universitario de Valencia participated in the study.

Lung cancer is the leading cause of death from cancer in the world. These figures can be reduced in the future if tobacco consumption decreases and early detection protocols are implemented using imaging techniques, such as CT scans.