Background: The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double-blind, placebo-controlled, prostate cancer prevention study funded by the National Cancer Institute and conducted by SWOG (Southwest Oncology Group). A total of 35,533 men were assigned randomly to one of four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, placebo + placebo). At the time of the trial's development, NIH had invested substantial resources in evaluating the potential benefits of these antioxidants. To capitalize on the knowledge gained from following a large cohort of healthy, aging males on the effects of selenium and/or vitamin E, ancillary studies with other disease endpoints were solicited. Methods: Four ancillary studies were added. Each drew from the same population but had independent objectives and an endpoint other than prostate cancer. These studies fell into two categories: those prospectively enrolling and following participants (studies of Alzheimer's disease and respiratory function) and those requiring a retrospective medical record review after a reported event (cataracts/age-related macular degeneration and colorectal screening). An examination of the challenges and opportunities of adding ancillary studies is provided. The impact of the ancillary studies on adherence to SELECT was evaluated using a Cox proportional hazards model. Results: While the addition of ancillary studies appears to have improved participant adherence to the primary trial, this did not come without added complexity. Activation of the ancillary studies happened after the SELECT randomizations had begun resulting in accrual problems to some of the studies. Study site participation in the ancillary trials varied greatly and depended on the interest of the study site principal investigator. Procedures for each were integrated into the primary trial and all monitoring was done by the SELECT Data and Safety Monitoring Committee. The impact of the early closure of the primary trial was different for each of the ancillary trials. Conclusions: The ancillary studies allowed study sites to broaden the research opportunities for their participants. Their implementation was efficient because of the established infrastructure of the primary trial. Implementation of these ancillary trials took substantial planning and coordination but enriched the overall primary trial.

This doctoral thesis is dealing with the correlation of morphological, immunohistochemical and genetical findings in malignant tumors of salivary glands. The first half of the thesis comprises the summary of current knowledge about salivary malignancies. The second half is presenting the research itself. The research results are divided into three parts. The first part is presenting the method of "2-step diagnostic test" of malignant tumors. This screening test aims to find new, so far not described gene aberrations with a focus on malignant tumors of salivary glands. This method takes place in two consecutive steps. In the first step the material is examined by an immunohistochemical mixture of antibodies, which non-specifically detects aberration in the genes NTRK1-3, ALK and ROS1. In the second step all positive cases are subjected to highly sensitive and specific molecular-genetic examination by the method of next generation sequencing (NGS) using the Archer kit. In the second part of the work there has been designed the approach to the cytological diagnosis of salivary secretory carcinoma by the fine-needle aspiration (FNA). This part is describing to the details the cytomorphology of secretory carcinoma in both, Pap smears and cell blocks, from which additional immunocytochemical and genetic...