RESUMEN
BACKGROUND: The average sensitivity of conventional cytology for the identification of cancer cells in effusion specimens is only approximately 58%. DNA image cytometry (DNA-ICM), which exploits the DNA content of morphologically suspicious nuclei measured on digital images, has a sensitivity of up to 91% for the detection of cancer cells. However, when performed manually, to our knowledge to date, an expert needs approximately 60 minutes for the analysis of a single slide. METHODS: In the current study, the authors present a novel method of supervised machine learning for the automated identification of morphologically suspicious mesothelial and epithelial nuclei in Feulgen-stained effusion specimens. The authors compared this with manual DNA-ICM and a gold standard cytological diagnosis for 121 cases. Furthermore, the authors retrospectively analyzed whether the amount of morphometrically abnormal mesothelial or epithelial nuclei detected by the digital classifier could be used as an additional diagnostic marker. RESULTS: The presented semiautomated DNA karyometric solution identified more diagnostically relevant abnormal nuclei compared with manual DNA-ICM, which led to a higher sensitivity (76.4% vs 68.5%) at a specificity of 100%. The ratio between digitally abnormal and all mesothelial nuclei was found to identify cancer cell-positive slides at 100% sensitivity and 70% specificity. The time effort for an expert therefore is reduced to the verification of a few nuclei with exceeding DNA content, which to our knowledge can be accomplished within 5 minutes. CONCLUSIONS: The authors have created and validated a computer-assisted bimodal karyometric approach for which both nuclear morphology and DNA are quantified from a Feulgen-stained slide. DNA karyometry thus increases the diagnostic accuracy and reduces the workload of an expert when compared with manual DNA-ICM.
Asunto(s)
Aneuploidia , Núcleo Celular/patología , Cariometría/métodos , Aprendizaje Automático , Neoplasias/patología , ADN de Neoplasias/aislamiento & purificación , Diagnóstico por Computador/métodos , Epitelio/patología , Humanos , Citometría de Imagen/métodos , Cariometría/normas , Neoplasias/genética , Sensibilidad y EspecificidadRESUMEN
Classification plays a central role in quantitative histopathology. Success is expressed in terms of the accuracy of prediction for the classification of future data points and an estimate of the prediction error. The prediction error is affected by the chosen procedure, e.g., the use of a training set of data points, a validation set, an independent test set, the sample size and the learning curve of the classification algorithm. For small samples procedures such as the "jackknife," the "leave one out" and the "bootstrap" are recommended in order to arrive at an unbiased estimate of the true prediction error. All of the procedures rest on the assumption that the data set used to derive a classification rule is representative for the diagnostic categories involved. It is this assumption that in quantitative histopathology has to be carefully verified before a clinically generally valid classification procedure can be claimed.
Asunto(s)
Sistemas Especialistas , Técnicas Histológicas/clasificación , Técnicas Histológicas/normas , Cariometría/clasificación , Cariometría/normas , Patología Clínica/clasificación , Patología Clínica/normas , Algoritmos , Humanos , Modelos Estadísticos , Valor Predictivo de las Pruebas , Control de CalidadRESUMEN
The ideal chemopreventive agent targets pre-neoplastic changes and intraepithelial neoplasia, preventing progression over time without notable side effects. Assessment of success of chemopreventive intervention in the short and medium term remains a challenge, and in this review the suggestion is investigated that karyometric measurements constitute suitable markers of chemopreventive efficacy. Karyometry provides the sensitivity required to detect small differences amidst relatively high biological variability. It can help establish progression curves of intraepithelial neoplasia (IEN) to invasive cancer, and thus detect chemopreventive effects. Such effects can be observed in two ways, at the group level (intervention vs. placebo), and at the case (or patient) level. The latter is more difficult to establish, necessitating the development of specialised statistical methods. Analysis of between-case and within-case heterogeneity can reveal useful information about cancer progression and prevention. We suggest that karyometry can objectively quantify IEN progression, providing a framework for statistically securing chemopreventive effects. It can act as an integrating biomarker by detecting chemopreventive activity even when the mechanism for a given progression pathway is unknown, or when multiple pathways exist. The sensitivity of karyometric detection can help optimise the design of clinical trials of novel chemopreventive agents by decreasing trial duration and/or sample size.
Asunto(s)
Carcinoma/prevención & control , Neoplasias/prevención & control , Lesiones Precancerosas/prevención & control , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/patología , Carcinoma/patología , Carcinoma Ductal de Mama/patología , Progresión de la Enfermedad , Diagnóstico Precoz , Eflornitina/uso terapéutico , Humanos , Cariometría/métodos , Cariometría/normas , Masculino , Neoplasias/patología , Lesiones Precancerosas/patología , Neoplasia Intraepitelial Prostática/patología , Neoplasias de la Próstata/patología , Sensibilidad y EspecificidadRESUMEN
The objective of this study was to evaluate nuclear normality in intracytoplasmic sperm injection (ICSI)-selected epididymal sperm from obstructive azoospermic (OA) patients. We evaluated whether the selection criteria used in routine ICSI (morphology and motility at a magnification of 400x) is adequate for selecting "normal" sperm from epididymal samples. Surgically retrieved spermatozoa from the caput epididymis of 15 OA patients and ejaculated sperm samples from 9 normospermic donors were evaluated with a DNA-specific stain (Feulgen) and in combination with the computerized karyometric image analysis (CKIA) system. Original (unselected) samples and ICSI-selected sperm were compared in donor and patient samples. In the original fraction, a larger variation in almost all measured parameters was found in epididymal sperm than in ejaculated sperm. After sperm selection, the morphometry was comparable between epididymal and ejaculated sperm. However, for those parameters related to the DNA stainability and chromatin texture (nuclear condensation), significant differences between patients and donors were observed. This result suggests that the size and form of the sperm do not necessarily hold similar internal structures. Thus, the frequency of "normal" sperm significantly increased after ICSI selection, but the improvement was more marked in donor than in OA patients' samples. In conclusion, at least a twofold increase in the number of normal spermatozoa was achieved after ICSI selection. The heterogeneity in the stainability and chromatin condensation of epididymal samples from OA patients indicates that some of the selected spermatozoa have a hypocondensed or hypercondensed chromatin. Even in the best of donor cases, no more than 55% of the selected sperm scored normal with CKIA, indicating that the present routine ICSI selection criteria are not sufficient for selecting normal condensed nuclei.