Doctoral Defense in Health Sciences - Hrönn Harðardóttir

On Friday, June 6, 2025, Hrönn Harðardóttir will defend her doctoral dissertation in Health Sciences at the Faculty of Medicine, University of Iceland. The dissertation is titled: The role of the psychobiological stress response to a lung cancer diagnosis in tumor biology and survival.

Opponents are Dr. Maria Planck, Associate Professor at Lund University, Sweden, and Dr. Judith Prins, Professor at Radboud University, the Netherlands.

The academic advisor and supervisor was Professor Unnur Anna Valdimarsdóttir, Dean of the School of Health Sciences, University of Iceland. Other members of the doctoral committee were Professor Thor Aspelund, Professor Heiðdís Valdimarsdóttir, Professor Susan K. Lutgendorf, Professor Magnús Karl Magnússon, and Professor Tómas Guðbjartsson.

Professor Sædís Sævarsdóttir, Vice-Dean of the Faculty of Medicine, will chair the ceremony, which will take place in the Ceremonial Hall of the University of Iceland (Hátíðasalur) and begins at 9:00 AM.

Abstract

Lung cancer is the second and third most common cancer among men and women in the Nordic countries and is the leading cause of all cancer deaths. Receiving a cancer diagnosis, particularly lung cancer, is an extremely stressful experience that may have further health consequences for the patients. Psychological distress activates the sympathetic nervous system, which can enhance tumor progression. Data is scarce on the psychobiological stress response during the diagnostic work-up and diagnosis of lung cancer as well as its potential role in prognostic markers and survival.
The research of this thesis is based on the LUCASS study (LUng CAncer, Stress and Survival), a prospective cohort study performed at university hospitals in Reykjavík, Iceland, and Uppsala, Sweden, designed to investigate the psychobiological stress responses in patients undergoing adiagnostic work-up for suspected lung cancer.

Overall, the findings of this thesis highlight that receiving a lung cancer diagnosis is associated with a marked increase in perceived psychological distress, and patients experience high levels of posttraumatic stress shortly after the diagnosis. Urinary levels of catecholamines were already elevated before the lung cancer diagnosis was established, with no clear link to distress levels at that time point. Nevertheless, we demonstrate that pre-diagnostic distress is strongly associated with levels of beta-2-adrenergic receptors on the tumor cells.

Finally, this work provides evidence for the role of psychobiological distress pathways in the survival of this vulnerable patient group, as both higher distress levels and levels of urinary norepinephrine before diagnosis were associated with lung cancer-specific survival. These results underscore the complex psychobiological stress responses to a lung cancer diagnosis and call for further research on the intricate connection between patients’ mental distress at diagnosis, tumor biology, and survival outcomes in lung cancer.

About the doctoral candidate

Hrönn Harðardóttir was born in 1967 in Reykjavík. She completed her medical degree at the University of Iceland in 1993. In 1997, she moved to the Netherlands for further studies and was certified as a specialist in internal medicine in 2005, followed later that year by certification in pulmonary medicine from the Radboud University Medical Center in Nijmegen, the Netherlands. Since 2006, Hrönn has worked as an internist and pulmonologist at Landspítali – the National University Hospital of Iceland. Alongside her clinical work, she has taught anatomy and communication at the Faculty of Medicine, University of Iceland. The doctoral project was undertaken in parallel with part-time clinical duties at Landspítali, committee work, and teaching at both the undergraduate and graduate levels at the University of Iceland.
Her parents are Rut Rebekka Sigurjónsdóttir and Hörður Kristinsson. Hrönn is married to physician Jón Örvar Kristinsson, and together they have four children and five grandchildren.