RESUMO
Classification on the basis of gene expression data derived from RNA-seq promises to become an important part of modern medicine. We propose a new classification method based on a model where the data is marginally negative binomial but dependent, thereby incorporating the dependence known to be present between measurements from different genes. The method, called qtQDA, works by first performing a quantile transformation (qt) then applying Gaussian quadratic discriminant analysis (QDA) using regularized covariance matrix estimates. We show that qtQDA has excellent performance when applied to real data sets and has advantages over some existing approaches. An R package implementing the method is also available on https://github.com/goknurginer/qtQDA.
RESUMO
The objective of this study was to determine the incidence of thyroid gland invasion in laryngeal and hypopharyngeal squamous cell carcinoma; and the association between clinicopathological parameters and thyroid gland invasion. Medical records of 75 patients with laryngeal and hypopharyngeal squamous cell carcinoma who underwent total laryngectomy with thyroidectomy were reviewed, retrospectively. Preoperative computed tomography scans, clinical and operative findings, and histopathological data of the specimens were evaluated. There were 73 male and two female patients with an age range of 41-88 years (mean 60.4 years). Hemithyroidectomy was performed in 62 (82.7 %) and total thyroidectomy was performed in 13 patients (17.3 %). Four patients had histopathologically proven thyroid gland invasion (5.3 %). In three patients, thyroid gland involvement was by means of direct invasion. Thyroid gland invasion was significantly correlated with thyroid cartilage invasion. Therefore, prophylactic thyroidectomy should not be a part of the treatment policy for these tumors.