Public Defence: Else Marie Opsahl
Cand.med. Else Marie Opsahl at Institute of Clinical Medicine will be defending the thesis “Medullary Thyroid Carcinoma in Norway. Clinical, molecular-biological and follow up studies” for the degree of PhD (Philosophiae Doctor).
Trial Lecture – time and place
See Trial Lecture.
- First opponent: Professor Jan Zedenius, Department of Molecular Medicine and Surgery, Karolinska Institutet, Sweden
- Second opponent: Professor Per Hellman, Department of Surgical Sciences, Endocrine surgery, Akademiska skjukhuset Uppsala, Sweden
- Third member and chair of the evaluation committee: Professor Kristin Bjørnland, Faculty of Medicine, University of Oslo
Chair of the Defence
Professor Emeritus Grete Botten, Faculty of Medicine, University of Oslo
Professor Trine Bjøro, Faculty of Medicine, University of Oslo
This thesis includes the first nationwide population-based studies concerning medullary thyroid carcinoma (MTC) in Norway during the last 40 years. The multicenter studies by Opsahl and colleagues, in four different cohorts, give scientific updates in diagnostics, treatment and outcome in Norwegian patients with MTC. The aims were to evaluate clinical course, calcitonin as predictor in thyroid surgery and prognostic factors for outcome in patients with MTC, both hereditary and sporadic, as well as molecular biological aspects. During 1994-2016, MTC accounted for 4,2 % of thyroid carcinoma. When comparing trends over two study periods, the MTC incidence increased from 0.18 to 0.25:100,000 per year and MTC disease control improved with earlier disease detection and better patient outcome. Preoperative basal serum calcitonin level is a good marker for timing and extent of thyroid surgery. When studying patients with multiple endocrine neoplasia type 2A (MEN2A) diagnosed 1974-2015, preoperative calcitonin level alone was an indicator for optimal timing and extent of thyroid surgery. However, when studying patients with MTC, hereditary and sporadic, during 2003-2016 with sensitive calcitonin analysis, the calcitonin level could not predict the need for prophylactic surgery in the lateral neck compartments. Tumor stage and age at time of diagnosis are the main prognostic factors governing cure and survival, but surgical accuracy has prognostic impact. Low ratio between metastatic lymph nodes and total number of resected lymph nodes is independent prognostic factor for cure and survival. Despite the advanced tumour stage at the time of diagnosis, the MTC tumour behaviour in the six Norwegian MEN2B study patients from 1988-2017, showed slow disease progression. Additional somatic cancer driver mutations were not found. Further research into microbiological aspects in MTC, both sporadic and hereditary, is needed to better understand the biological prognostic factors.
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