Roland Van Velthoven

Image cytometry determination of ploidy level, proliferative activity, and nuclear size in a series of 314 transitional bladder cell carcinomas☆

Image cytometry was carried out on 281 superficial (Ta and T1) and 33 invasive (T2 to T4) bladder cancers. The parameters used to characterize these bladder tumors were: (1) histopathological grading, (2) clinical staging, (3) tumor size, (4) deoxyribonucleic acid (DNA) index (DI), (5) DNA histogram type (DHT), (6) percentage of euploid (diploid plus tetraploid) cells, (7) percentage of polyploid cells (> 5C DNA content), (8) proliferative activity (S phase fraction value), and (9) nuclear area (NA). The proliferative activity of the tumors was not related to either histopathological grade or to clinical stage, but it was related to the DHT parameter, which made it possible to identify diploid, hyperdiploid, triploid, hypertriploid, tetraploid, and polymorphic tumors. The hypertriploid tumors exhibited a significantly lower proliferative activity than the nonhypertriploid ones. Although both the DI and the NA values correlated significantly with histopathological grading, only the NA values correlated significantly with clinical staging. We further observed that some grade III bladder tumors were definitely diploid, whereas some grade I tumors were highly aneuploid. We thus hypothesize that the ploidy level of a given tumor reflects its age directly and its aggressiveness only very indirectly. In our opinion aneuploidy is only an indirect marker of aggressiveness because it reflects the fact that a malignant tumor is old, ie, has been present in a patient over a long period of time and has had ample time to express its malignancy at the clinical level. A significant relationship was accordingly obtained between tumor size and ploidy level with the highest proportion of aneuploid tumors and the highest percentage of polyploid cell nuclei being observed among the largest bladder tumors.

Computerized morphonuclear cell image analyses of malignant disease in bladder tissues.

We analyzed the relationship between several morphonuclear parameters related to nuclear size, densitometry (deoxyribonucleic acid content and ploidy) and the chromatin pattern versus the histopathological grading of 46 bladder cancer samples graded according to the World Health Organization classification. We used a SAMBA 200 cell image processor with software allowing for the discrimination of 15 different parameters on Feulgen-stained imprint smears. In addition, we set up preliminary data banks that enable objective and reproducible grading of unknown cases. This approach must be validated in a large series of cases to create an expert system for bladder malignancy diagnosis.

Classification strategies for the grading of renal cell carcinomas, based on nuclear morphometry and densitometry.

The various grading systems proposed for renal cell carcinomas all suffer from problems related to inter‐observer variability. Some of these grading systems are based, either partially or wholly, on morphonuclear criteria, such as nuclear size and shape, anisonucleosis, and chromatin pattern. These criteria can be quantitatively (and thus objectively) evaluated by means of the computer‐assisted microscopic analysis of Feulgen‐stained nuclei. In the present work, 39 quantitative variables, including two morphometric, 28 chromatin pattern‐related, and nine DNA ploidy level‐related, were computed for 65 renal cell carcinomas. The actual diagnostic information contributed by each variable was determined by means of multifactorial statistical analysis (discriminant analysis) and two artificial intelligence‐related methods of data classification (the decision tree and production rule methods). The results show that quantitative information, as provided by the computer‐assisted microscopy of Feulgen‐stained nuclei and analysed by means of artificial intelligence‐related methods of data classification, contributes significant diagnostic information for the grading of renal cell carcinoma, thus reducing the problem of inter‐observer reproducibility.

Identification by quantitative chromatin pattern analysis of patients at risk for recurrence of superficial transitional bladder carcinoma.

PURPOSEnBased on the actual clinical outcomes of 132 fully documented patients with superficial transitional cell carcinoma of the bladder, we characterize the risk of recurrence and/or progression by computer assisted image microscopy applied to Feulgen stained nuclei.nnnMATERIALS AND METHODSnEach tumor was characterized by the conventional grading and staging systems as well as by cytometry generated variables describing nuclear DNA content, nuclear morphometry and chromatin patterns. These data were submitted to discriminant analysis to establish a model distinguishing between 2 groups of patients. Group 1 included cases with remission for more than 60 months and group 2 cases presented with recurrence with or without progression within 12 months of transurethral bladder resection. This latter model was then validated by Kaplan-Meyer analysis of the full data set.nnnRESULTSnAs evidenced by Kaplan-Meier analysis, the discriminant factor generated by discriminant analysis of cytometry generated variables provided a cutoff value for distinguishing between low and high risks of recurrence (p <0.00001). In contrast, conventional grading and staging systems were not able to make such efficient distinction.nnnCONCLUSIONSnThese 2 groups can be used as references with which new cases can be compared to prognosticate disease behavior independently of histopathological grading and/or clinical staging.

The use of the decision tree technique and image cytometry to characterize aggressiveness in World Health Organization (WHO) grade II superficial transitional cell carcinomas of the bladder

The aggressiveness of human bladder tumours can be assessed by means of various classification systems, including the one proposed by the World Health Organization (WHO). According to the WHO classification, three levels of malignancy are identified as grades I (low), II (intermediate), and III (high). This classification system operates satisfactorily for two of the three grades in forecasting clinical progression, most grade I tumours being associated with good prognoses and most grade III with bad. In contrast, the grade II group is very heterogeneous in terms of their clinical behaviour. The present study used two computer‐assisted methods to investigate whether it is possible to sub‐classify grade II tumours: computer‐assisted microscope analysis (image cytometry) of Feulgen‐stained nuclei and the Decision Tree Technique. This latter technique belongs to the Supervised Learning Algorithm and enables an objective assessment to be made of the diagnostic value associated with a given parameter. The combined use of these two methods in a series of 292 superficial transitional cell carcinomas shows that it is possible to identify one subgroup of grade II tumours which behave clinically like grade I tumours and a second subgroup which behaves clinically like grade III tumours. Of the nine ploidy‐related parameters computed by means of image cytometry [the DNA index (DI), DNA histogram type (DHT), and the percentages of diploid, hyperdiploid, triploid, hypertriploid, tetraploid, hypertetraploid, and polyploid cell nuclei], it was the percentage of hyperdiploid and hypertetraploid cell nuclei which enabled identification, rather than conventional parameters such as the DI or the DHT.

Improving the prognostic value of histopathological grading and clinical staging in renal cell carcinomas by means of computer-assisted microscopy.

The present work aims to refine prognosis in cases of renal cell carcinoma (RCC) by integrating a variety of parameters with the prognostic information provided by histopathological grading and clinical staging, carried out on a series of 97 RCCs. To this end, Feulgen‐stained RCC cell nuclei were characterized by means of 38 variables describing nuclear DNA ploidy levels and morphology. All of these data were subjected to a principal components analysis. On the basis of this multivariate analysis, Fuhrman grade II was subdivided into grades II− and II+, and Fuhrman grade III into grade III− and III+. The same kind of subcategorization was performed in the case of the T2 and T3 clinical stages. The results show that the classification into grade II− and III− RCCs correspond to a more favourable prognosis than grade II+ and III+, to which shorter survival periods were attributable. Similar results were obtained for the subcategorization of the T2 and T3 clinical stages. Very simple biological characterizations of these grade‐ or stage‐related RCC groups were obtained by means of a decision tree approach applied to the cytometry‐generated variables. The resulting classification rules were validated on a new series of 18 patients and enabled very accurate predictions of survival. Copyright

Use of computerized cell image analysis to characterize cell nucleus populations from normal and neoplastic renal tissues

We studied 55 renal tissue samples from 16 patients corresponding to normal (19 samples, group 1), low-grade (18 samples, group 2), and high-grade (18 samples, group 3) tumoral tissues. For this purpose, we used digital cell image analysis (the SAMBA 200 processor) to describe the morphonuclear patterns of Feulgen-stained nuclei from the 3 above-mentioned groups. Our results show that nuclear DNA ploidy is positively correlated with histopathological differentiation, which is also positively correlated with an increase in nuclear DNA heterogeneity. Morphometric and textural parameters computed on such Feulgen-stained nuclei make it possible to describe the typical morphonuclear patterns of normal, low-grade, and high-grade neoplastic renal tissues. Using multiparametric, i.e. principal-component and canonical analyses, we set up preliminary morphonuclear data banks that we used to assess the diagnosis of 6 ungraded samples. We expect that this kind of morphonuclear data banks might be helpful, on one hand, to select specific morphonuclear parameters related to patient survival, and on the other hand to establish the cytological diagnosis of deep fine-needle aspiration material, sonographically assisted, on suspicious kidneys. Such hypotheses are now under further study.

The chromatin pattern of cell nuclei is of prognostic value for renal cell carcinomas

Using a series of 105 renal cell carcinomas (RCCs) we investigated whether features quantitatively describing the appearance of Feulgen‐stained nuclei and, more particularly, of their chromatin (on the basis of computer‐assisted microscopy) can contribute any significant prognostic information. Thirty morphonuclear and 8 nuclear DNA content‐related variables were thus generated. The actual prognostic values of this set of cytometric variables was compared (by means of discriminant statistical analysis) to conventional diagnostic and/or prognostic markers including histopathological grades, tumour invasion levels and the presence or absence of metastases. We obtained complete clinical follow‐ups for 49 of the 105 RCC patients under study, making it possible to define a subset of patients with a bad prognosis (i.e., who died in the 12 months following nephrectomy) and a subset of patients with a good prognosis (i.e., who survived at least 24 months following nephrectomy). An original method of data analysis related to artificial intelligence (decision tree induction) enabled a strong prognostic model to be set up. In the case of 10 new patients, this model identified all the dead patients as having a bad survival status, with a total of 8 correct predictions. Another prognostic model similarly generated enabled the correct predictions to be confirmed.

Focal Treatment for Unilateral Prostate Cancer Using High-Intensity Focal Ultrasound: A Comprehensive Study of Pooled Data

Abstract Background: Focal therapy for prostate cancer (PCa) remains experimental. Aim of the current study is to review available evidence and perform a pooled analysis exploring oncologic and functional results of high intensity focus ultrasound (HIFU) focal therapy for the treatment of unilateral PCa. Methods: The National Library of Medicine Database was searched for relevant articles. A wide search was performed, including the combination of following words: “HIFU,” “prostate,” “cancer,” and “focal.” Overall, 167 articles were reviewed. Of these, seven articles were identified and eligible for the pooled analysis. Data on HIFU hemiablation or focal prostate ablation, oncologic and functional results were pooled from these seven studies that included 366 men with unilateral PCa. Results: In the 366 analyzed cases, mean age was 67 years (95% confidence interval 66–69), and mean preoperative prostate-specific antigen was 6.4u2009ng/cc (5.5–7.4). Three studies included PCa up to Gleason 7 (3u2009+u20094), three stud...BACKGROUNDnFocal therapy for prostate cancer (PCa) remains experimental. Aim of the current study is to review available evidence and perform a pooled analysis exploring oncologic and functional results of high intensity focus ultrasound (HIFU) focal therapy for the treatment of unilateral PCa.nnnMETHODSnThe National Library of Medicine Database was searched for relevant articles. A wide search was performed, including the combination of following words: HIFU, prostate, cancer, and focal. Overall, 167 articles were reviewed. Of these, seven articles were identified and eligible for the pooled analysis. Data on HIFU hemiablation or focal prostate ablation, oncologic and functional results were pooled from these seven studies that included 366 men with unilateral PCa.nnnRESULTSnIn the 366 analyzed cases, mean age was 67 years (95% confidence interval 66-69), and mean preoperative prostate-specific antigen was 6.4u2009ng/cc (5.5-7.4). Three studies included PCa up to Gleason 7 (3u2009+u20094), three studies did include also Gleason 7 (4u2009+u20093), whereas one study had no limitation in terms of Gleason score. Regarding early complications, low-grade Clavien-Dindo I-II were reported in 26% (16-37), whereas high-grade Clavien-Dindo ≥III were found in 3.8% (0-8.6). Analyzing oncologic outcomes mean follow-up was 26 months (23-31): at one year after HIFU, negative biopsy rate for clinically significant PCa was 87% (79-96), whereas salvage treatment-free survival rate was 92% (85-98). Regarding functional outcomes, reported potency rates were 74% (64-84), and continence 96% (91-100), although definitions of potency and continence were not homogenous across studies.nnnCONCLUSIONSnThis pooled analysis of the results of focal HIFU treatment of PCa shows promising oncologic and functional outcomes. Well-selected patients may be candidates for such a conservative partial treatment of the gland. Well-designed trials are awaited to compare HIFU focal treatment with current standard of care.