Biomarkers in pulmonary carcinoid tumors

Pulmonary carcinoid (PC) tumors are rare neuroendocrine lung neoplasms that have in general an indolent clinical course. Based on morphology, PC tumors are categorized into typical carcinoid (TC) tumors and atypical carcinoid (AC) tumors. The primary treatment is surgery, while there is no consensus on the treatment of metastatic disease. Thus, effective and more targeted therapies are needed for the PC patients who are inoperable or not curable with surgery alone. While histologic subtype and stage are important prognostic factors, other predictive and prognostic factors or biomarkers are urgently needed for individualized treatment and patient-tailored surveillance protocols. The main aim of this thesis was to find tissue-based biomarkers in PC tumors by utilizing the Finnish hospital-integrated biobanks as a source of the study material. Moreover, the performance of these biobanks in distributing material for a research of a rare cancer was evaluated. The nationwide study cohort consisted of 224 PC tumor patients operated on between 1990 and 2013 in Finland. Eighty-one per cent (n=182) of the tumors were classified as TCs and 19% (n=42) as ACs. Hilar/mediastinal lymph node involvement at the time of primary surgery as well as metastatic disease in general was more common in AC patients than in TC patients. The follow-up time of the patients varied between