Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.
Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Professor Jesper Grau Eriksen, Aarhus University, Denmark
- Second opponent: Senior Consultant Hanne Tøndel, St. Olavs Hospital, Trondheim
- Third member and chair of the evaluation committee: Professor II Marte Lie Høivik, University of Oslo
Chair of the Defence
Professor II Marit H. Andersen, University of Oslo
Principal Supervisor
Cecilie Dephin Amdal, Oslo University Hospital
Summary
Radiotherapy (RT) is one of the main curative treatments of head and neck cancer (HNC). Currently, there is insufficient data concerning long-term RT-induced side effects. Such late effects can compromise health-related quality of life (HRQoL).
The overall thesis aim was to obtain knowledge on late effects in HNC survivors more than five years after RT, with emphasis on patient-reported xerostomia, dysphagia, and chronic fatigue (CF). We sought to understand underlying mechanisms and associated factors.
In a cross-sectional study with 263 Norwegian HNC survivors and a median follow-up time of 8.5 years post-RT, we found high prevalence of xerostomia, dysphagia, and CF with 58%, 31%, and 33%, respectively.
As inflammation has been proposed as a possible mechanism, we investigated serum levels of six pro-inflammatory cytokines as potential biomarkers. We did not detect differences between participants with and without these late effects. However, the entire HNC survivor group had significantly higher levels of IL-6 and IP-10 compared to healthy controls, which indicates an ongoing systemic response, but the relevance is uncertain.
RT doses to swallowing organs located below the tongue bone, but not above it, were found to impact long-term dysphagia. This was confirmed in multivariable analyses, which additionally demonstrated advanced age and female sex as associated factors. Our data exhibited suboptimal fit in existing prediction models, calling for development of models that are better tailored for long-term dysphagia.
CF was found to be two-fold as prevalent in the HNC survivors as in the general population. In multivariable analyses, CF was not associated with RT doses to organs of the central nervous system, but female sex, comorbidity, and RT technique were associated with CF.
The results of this project contribute to identifying individuals at risk of developing late effects as basis for better health care, and thereby help improve HRQoL for HNC survivors.
Additional information
Contact the research support staff.