Discrimination of healthy and colorectal cancer patients using FTIR and PLS-DA

Spectroscopic methods have already been used as effective tools in several studies involving the detection of cancer. Fourier transform infrared spectroscopy (FTIR) has already been applied in the discrimination of cancer cells and tissues or blood of patients with the disease, observing that this technique requires the use of chemometric algorithms to obtain such results. The aim of this study was to employ a partial least squares discriminant analysis (PLS-DA) with FTIR data in the discrimination of plasma samples from patients with colorectal cancer (RCC) and healthy individuals. Multivariate analysis was performed using PLS-DA of the sample triplicates (n=90) with different types of processing. The best PLS-DA condition was obtained using the 1st derivative, 1 orthogonal signal correction (OSC) and no pre-processing. With 1 factor only, the model presented a mean square error of cross-validation (RMSECV) of 0.0004 and coefficient of determination (r^2) of 1.0000. The accuracy, precision and sensitivity of the model were 100%

Perianal Paget's disease

Paget's disease most commonly affects the breast. Extramammary involvement is rare, and the most commonly affected sites are the vulva, anus, perianal region, and axilla. The disease may progress to invasive adenocarcinoma or synchronous cancers. Due to the lack of distinctive features and nonspecific presenting symptoms, Paget's disease may be misdiagnosed as other conditions, thus delaying the correct diagnosis. We report a case of extramammary Paget's disease in the perianal region that initially presented as an irregular, circumferential, scaling lesion with eczematous eruptions. Immunology and immunohistochemistry confirmed the diagnosis. Although surgery is the standard treatment, the patient opted for pelvic radiotherapy associated with radiosensitizing chemotherapy. Resumo: A doença de Paget acomete mais comumente a mama. Os focos extramamários são raros e os locais mais habitualmente acometidos são vulva, ânus, região perianal e axila. A patologia envolve a evolução da doença para adenocarcinoma invasivo ou neoplasias sincrônicas. Devido à singularidade e sua aparência inespecífica, a doença pode ser confundida com outras comorbidades, retardando o diagnóstico. O objetivo foi relatar um caso de doença de Paget extramamária na região perianal, a qual inicialmente apresentou lesão circunferencial com erupção eczematosa, descamativa e irregular. A confirmação diagnóstica foi por meio de exames imuno-histoquímico e imunológico. O tratamento padrão da doença é cirúrgico, porém optou-se por radioterapia pélvica associada à quimioterapia radiossensibilizante. Keywords: Paget's disease, Extramammary Paget's disease, Perianal, Palavras-chave: Doença de Paget, Doença de Paget extramamária, Periana