Correlations of Ki-67 and PCNA to DNA ploidy, S-phase fraction and survival in uveal melanoma

Correlation Analysis of Apparent Diffusion Coefficient Histogram Parameters and Clinicopathologic Features for Prognosis Prediction in Uveal Melanoma

Purpose

To investigate the correlation between apparent diffusion coefficient (ADC) histograms and high-risk clinicopathologic features related to uveal melanoma (UM) prognosis.

Methods

This retrospective study included 53 patients with UM who underwent diffusion-weighted imaging (DWI) between August 2015 and March 2024. Axial DWI was performed with a single-shot spin-echo echo-planar imaging sequence. ADC histogram parameters of ADCmean, ADC50%, interquartile range (IQR), skewness, kurtosis, and entropy were obtained from DWI. The relationships between histogram parameters and high-risk clinicopathological characteristics including tumor size, preoperative retinal detachment, histological subtypes, Ki-67 index, and chromosome status, were analyzed by Spearman correlation analysis, Mann-Whitney U test, or Kruskal-Wallis test.

Results

A total of 53 patients (mean ± SD age, 55 ± 15 years; 22 men) were evaluated. The largest basal diameter (LBD) was correlated with kurtosis (r = 0.311, P = 0.024). Tumor prominence (TP) was correlated with entropy (r = 0.581, P < 0.001) and kurtosis (r = 0.273, P = 0.048). Additionally, significant correlations were identified between the Ki-67 index and ADCmean (r = -0.444, P = 0.005), ADC50% (r = -0.487, P = 0.002), and skewness (r = 0.394, P = 0.014). Finally, entropy was correlated with monosomy 3 (r = 0.541, P = 0.017).

Conclusions

The ADC histograms provided valuable insights into high-risk clinicopathologic features of UM and hold promise in the early prediction of UM prognosis.

Ki67 is a better marker than PRAME in risk stratification of BAP1-positive and BAP1-loss uveal melanomas

BACKGROUND

Accurate risk stratification of uveal melanoma (UM) patients is important for determining the interval and frequency of surveillance. Loss of BAP1 expression has been shown to be strongly associated with UM-related death and metastasis.

METHODS

In this study of 164 enucleated UMs, we assessed the prognostic role of preferentially expressed antigen in melanoma (PRAME) expression and Ki67 proliferation index measured by digital quantitation using QuPath programme in patients with BAP1-positive and BAP1-loss UMs.

RESULTS

In univariate analyses with log-rank tests and Kaplan-Meier curves, PRAME further stratified only overall survival (OS) in BAP1-positive and BAP1-loss tumour groups. However, Ki67 further stratified both OS and disease-free survival (DFS) in BAP1-positive and BAP1-loss tumour groups. In multivariate analyses, Ki67 percentage and BAP1 were independent survival predictors for both OS and DFS, whereas PRAME was not a significant covariate. In model comparisons, combined Ki67 and BAP1 performed better than combined PRAME and BAP1 in risk-stratifying patients for both OS and DFS. Ki67 was better than PRAME in risk stratification of BAP1-positive UMs. Low Ki67 index correlated with significantly prolonged DFS in BAP1-loss UMs.

CONCLUSION

A panel of Ki67 and BAP1 could be a helpful risk stratification strategy for UM.

Update on uveal melanoma: Translational research from biology to clinical practice (Review)

Uveal melanoma is the most common type of intraocular cancer with a low mean annual incidence of 5‑10 cases per million. Tumours are located in the choroid (90%), ciliary body (6%) or iris (4%) and of 85% are primary tumours. As in cutaneous melanoma, tumours arise in melanocytes; however, the characteristics of uveal melanoma differ, accounting for 3‑5% of melanocytic cancers. Among the numerous risk factors are age, sex, genetic and phenotypic predisposition, the work environment and dermatological conditions. Management is usually multidisciplinary, including several specialists such as ophthalmologists, oncologists and maxillofacial surgeons, who participate in the diagnosis, treatment and complex follow‑up of these patients, without excluding the management of the immense emotional burden. Clinically, uveal melanoma generates symptoms that depend as much on the affected ocular globe site as on the tumour size. The anatomopathological study of uveal melanoma has recently benefited from developments in molecular biology. In effect, disease classification or staging according to molecular profile is proving useful for the assessment of this type of tumour. Further, the improved knowledge of tumour biology is giving rise to a more targeted approach to diagnosis, prognosis and treatment development; for example, epigenetics driven by microRNAs as a target for disease control. In the present study, the main epidemiological, clinical, physiopathological and molecular features of this disease are reviewed, and the associations among all these factors are discussed.

Low-Pass Whole-Genome Sequencing as a Method of Determining Copy Number Variations in Uveal Melanoma Tissue Samples

Analysis of specific somatic copy number alterations (SCNAs) using multiplex ligation-dependent probe amplification (MLPA) is used routinely as a prognostic test for uveal melanoma (UM). This technique requires relatively large amounts of input DNA, unattainable from many small fine-needle aspirate biopsy specimens. Herein, we compared the use of MLPA with whole-genome amplification (WGA) combined with low-pass whole-genome sequencing (LP-WGS) for detection of SCNA profiles in UM biopsy specimens. DNA was extracted from 21 formalin-fixed, paraffin-embedded UM samples and SCNAs were assessed using MLPA and WGA followed by LP-WGS. Cohen's κ was used to assess the concordance of copy number calls of each individual chromosome arm for each patient. MLPA and WGA/LP-WGS detection of SCNAs in chromosomes 1p, 3, 6, and 8 were compared and found to be highly concordant with a Cohen's κ of 0.856 (bias-corrected and accelerated 95% CI, 0.770-0.934). Only 13 of 147 (8.8%) chromosomal arms investigated resulted in discordant calls, predominantly SCNAs detected by WGA/LP-WGS but not MLPA. These results indicate that LP-WGS might be a suitable alternative or adjunct to MLPA for the detection of SCNAs associated with prognosis of UM, for cases with limiting tissue or DNA yields.

Uveal melanoma: estimating prognosis

Uveal melanoma is the most common primary malignant tumor of the eye in adults, predominantly found in Caucasians. Local tumor control of uveal melanoma is excellent, yet this malignancy is associated with relatively high mortality secondary to metastasis. Various clinical, histopathological, cytogenetic features and gene expression features help in estimating the prognosis of uveal melanoma. The clinical features associated with poor prognosis in patients with uveal melanoma include older age at presentation, male gender, larger tumor basal diameter and thickness, ciliary body location, diffuse tumor configuration, association with ocular/oculodermal melanocytosis, extraocular tumor extension, and advanced tumor staging by American Joint Committee on Cancer classification. Histopathological features suggestive of poor prognosis include epithelioid cell type, high mitotic activity, higher values of mean diameter of ten largest nucleoli, higher microvascular density, extravascular matrix patterns, tumor-infiltrating lymphocytes, tumor-infiltrating macrophages, higher expression of insulin-like growth factor-1 receptor, and higher expression of human leukocyte antigen Class I and II. Monosomy 3, 1p loss, 6q loss, and 8q and those classified as Class II by gene expression are predictive of poor prognosis of uveal melanoma. In this review, we discuss the prognostic factors of uveal melanoma. A database search was performed on PubMed, using the terms “uvea,” “iris,” “ciliary body,” “choroid,” “melanoma,” “uveal melanoma” and “prognosis,” “metastasis,” “genetic testing,” “gene expression profiling.” Relevant English language articles were extracted, reviewed, and referenced appropriately.

A comparative transcriptomic analysis of uveal melanoma and normal uveal melanocyte

Background

Uveal melanoma is the most common primary intraocular tumor in adults in western countries. It is associated with very severe visual morbidity and may lead to distant metastases even after successful treatment of the primary tumor. In order to gain better insight into molecular mechanisms related to tumorigenesis and metastasis of uveal melanoma, we used next-generation sequencing technology (SOLiD, Life Technologies) to acquire global transcriptome alteration between posterior uveal melanoma cells and normal uveal melanocyte.

Results

From mRNAs of the cultured uveal melanoma cells and normal uveal melanocytes, we annotated more than 3.7×10⁷ and 2.7×10⁷ sequencing tags based on human Ensembl databases, respectively. For detailed analysis, we chose 5155 well-annotated genes mainly involved in the MAPK signaling pathway, cell cycle, cell adhesion junction, apoptosis, and P53 signaling pathways as well as melanogenesis. In an effort to confirm the authenticity of our sequencing results, we validated twenty-one identically differentially expressed genes by using quantitative real time PCR from cultured cell lines of other posterior uveal melanoma cells and normal uveal melanocytes.

Conclusion

We have identified a large number of potentially interesting genes for biological investigation of uveal melanoma. The expression profiling also provides useful resources for other functional genomic and transcriptome studies. These 21 potential genes could discriminate between uveal melanoma cells and normal uveal melanocyte, which may be indicative of tumorigenesis process. Our results further suggest that high-throughput sequencing technology provides a powerful tool to study mechanisms of tumogenesis in the molecular level.

Association between gene expression profile, proliferation and metastasis in uveal melanoma

PURPOSE

Uveal melanomas cluster into two molecular groups based on their gene expression profile. Tumors with the class 1 signature rarely metastasize, whereas those with the class 2 signature have a very high rate of metastasis. However, the biological basis for this metastatic propensity of class 2 tumors remains unclear. Towards such an explanation, this study was conducted to determine whether class 2 tumors have a higher proliferative rate than class 1 tumors.

MATERIALS AND METHODS

The study included 28 primary uveal melanomas with extensive clinical, pathologic, and genetic annotation, including age, gender, ciliary body involvement, tumor basal diameter, thickness, cell type, gene expression profile, status of chromosomes 3 and 8p, aneuploidy, and clinical outcome. Immunopositivity for Ki-67 was determined by counting all positive nuclei in representative whole tumor sections.

RESULTS

Ki-67 positivity was significantly associated with class 2 gene expression profile, loss of chromosome 3 and increased aneuploidy (P = 0.04, P = 0.004, and P = 0.03, respectively). Ki-67 positivity showed a borderline significant association with epithelioid cell type (P = 0.07). Receiver operating characteristic (ROC) analysis of Ki-67 positivity, using the class 2 signature as an endpoint, identified a Ki-67 score of approximately 20 cells per high power field as the optimal cut-off point between low and high risk for metastasis (log rank test, P = 0.01).

CONCLUSIONS

On average, class 2 uveal melanomas have a higher proliferative rate than class 1 tumors. Further work is needed to determine whether loss of chromosome 3, increased aneuploidy, or other factors may be responsible for the increased proliferation.

Spatial and temporal distribution of Ki-67 proliferation marker, Bcl-2 and Bax proteins in the developing human tooth

OBJECTIVE

To investigate the spatial and temporal expression of proliferation Ki-67 marker, pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins during early development of the human tooth.

MATERIALS AND METHODS

Histological sections of eight human conceptuses, 5-10 postovulatory weeks old, were used for immunolocalization for Ki-67, Bax and Bcl-2 markers. Quantification was performed by calculating the fraction of Ki-67 positive cells, expressed as a mean ± SD, and analysed by Mann-Whitney test, Kruskal-Wallis and Dunn's post hoc test.

RESULTS

In 6th-7th developmental weeks, the tooth germ and dental crest contained 37% of proliferating cells, which increased to 40% in the 8th week, and then decreased to 15% in the 10th week, whilst the proliferation in the ectomesenchyme subsequently dropped from 37% to 23%. Epithelial parts of the enamel organ displayed similar proliferation activity (31-36%), dental crest 10%, whilst enamel knot showed no proliferating activity. The tooth ectomesenchyme contained more proliferating cells (50%) than the jaw ectomesenchyme (35%), and both dropped to 28% in the 10th week. Ectomesenchyme between the tooth germs contained 23%, whilst the jaw ectomesenchyme contained 15% of proliferating cells. Bcl-2 expression had following pattern: strong in proliferating cells, moderate in tooth germs and dental crest, and weak in the ectomesenchyme. Bax co-expressed with Bcl-2 in the tooth germ and dental crest. In the reticulum and inner enamel epithelium Bcl-2 had prevalent expression, whilst Bax prevailed in the outer enamel epithelium and tooth ectomesenchyme.

CONCLUSIONS

Proliferating cells most likely influence growth of the tooth germ, Bcl-2 affects proliferation and differentiation of specific cell lineages, whilst Bax influences process of cell death.

Genomic Investigations of Posterior Uveal Melanoma

The specific genetic mechanisms responsible for the malignant behavior of uveal melanoma are not known. Unlike cutaneous melanoma, epidemiologic studies have not demonstrated a definitive germline form of uveal melanoma, though familial melanoma and racial predilections occur. Molecular cytogenetic characterization of uveal melanoma suggests that somatic deletions of chromosome 3 are associated with a worse prognosis. Microarray technology has been used to characterize uveal melanoma gene expression and may provide tests useful for determining prognosis. As an improved understanding of the cellular mechanisms used by uveal melanoma is gained, new opportunities to adapt or design therapeutic approaches may emerge.

The molecular basis of melanomagenesis and the metastatic phenotype

The last two decades have seen spectacular advances in our understanding of the biology of melanoma and, in particular, have elucidated the mechanisms operative in disease initiation and progression. With respect to the former, the genetics of melanoma and in particular the impact of genetic defects on dysregulation of the cell cycle are key issues in malignant transformation and are a major focus of this review. With respect to the latter, consideration also is given to the acquisition of growth factor autonomy and the capacity for invasion and metastasis from the standpoint of cell adhesion, motility, and matrix digestion. These events have specific morphologic correlates that will be briefly addressed. Where relevant, we will address certain of the modern pharmacogenetic strategies that flow from these novel observations concerning melanoma biology.

Cyclooxygenase-2 expression in human irradiated uveal melanomas

AIM

Previous studies have shown that radiotherapy is a stimulus for cyclooxygenase-2 (COX-2) expression and that use of COX-2 inhibitors enhances the radio sensitivity of tumor cells. The objective of this study was to evaluate COX-2 expression, and its correlation with tumor regrowth after irradiation, in enucleated eyes with uveal melanomas.

METHODS

Fifteen tissue samples from patients who underwent enucleation after radiotherapy between 1988 and 2001 were used. Nine cases (60%) were enucleated because of tumor regrowth and six (40%) because of severe complications of radiotherapy. Specimens were immunostained for COX-2, and tumor cells were evaluated for specific cytoplasmic and granular immunostaining. COX-2 expression for these cases was compared with that in the previous study including 40 non-irradiated uveal melanoma cases. COX-2 expression was also correlated with tumor regrowth after radiotherapy.

RESULTS

Two cases (13.3%) were positive and thirteen (86.7%) were negative for COX-2 expression. One of the positive cases had been enucleated because of tumor regrowth and one because of radiotherapy complications. There was no relationship between tumor regrowth and COX-2 expression. COX-2 expression was significantly lower in irradiated cases than in non-irradiated cases in the previous study (p<0.001).

CONCLUSIONS

In contrast with studies showing an increase of COX-2 expression in other irradiated malignancies, irradiation was not a factor inducing COX-2 in uveal melanomas. Radiotherapy may, moreover, be a factor that reduces COX-2 expression in uveal melanomas.

Proteomics in uveal melanoma research: opportunities and challenges in biomarker discovery

Uveal melanoma (UM) is the most frequent primary intraocular tumor in adult humans. Despite the significant advances in diagnosis and treatment of UM in the last decades, the prognosis of UM sufferers is still poor. Metastatic liver disease is the leading cause of death in UM and can develop after a long disease-free interval, suggesting the presence of occult micrometastasis. Proteomics technology has opened new opportunities for elucidating the molecular mechanism of complex diseases, such as cancer. This article will review the recent developments in biomarker discovery for UM research by proteomics. In the last few years, the first UM proteomics-based analyses have been launched, yielding promising results. An update on recent developments on this field is presented.

Prognosticators of melanoma, the melanoma report, and the sentinel lymph node

Since the 1960s, the clinical characteristics of melanoma, its histopathology and its biological basis have been the subject of intense study at pigmented lesion clinics in North America, Europe, and Australia. More recently, the immense database of the Melanoma Committee of the American Joint Committee on Cancer (AJCC) has been exploited through complex mathematical models to measure the impact of various histologic features of primary melanomas and of sentinel lymph node deposits and to correlate these parameters with patient survival. The wealth of modern information available to pathologists and clinicians has become of vital interest to the prognostication of the individual patient with melanoma. The purpose of this review is to bring to the attention of anatomic pathologists the essential characteristics of the pathology report for primary cutaneous melanoma in the modern era.

Cell proliferation during the early stages of human eye development

The distribution as well as the ultrastructural and biochemical characteristics of proliferating cells in the human eye were investigated in five conceptuses of 5-9 postovulatory weeks, using morphological techniques and Ki-67 immunostaining. The Ki-67 nuclear protein was used as a proliferation marker because of its expression in all phases of the cell cycle except the resting phase (G0). The labelling indices of Ki-67-positive cells were analysed by means of the Kruskal-Wallis ANOVA test and the Wilcoxon matched-pairs test. In the 5th week, mitotic cells were the most numerous between the two layers of the optic cup, the optic cup and stalk, and between the lens pit and the surface ectoderm. During the 6th week, cells were observed in the lens epithelium covering the whole cavity of the lens vesicle as well as in the neuroblast zone and the pigmented epithelium of the retina. At later stages (7th-9th weeks), Ki-67-positive cells were restricted to the anterior lens epithelium, the outer neuroblast zone, and the pigmented retina. Throughout all stages examined, mitotic figures were found lying exclusively adjacent to the intraretinal space. Early in the lens pit, they were confined to the free epithelial surface, and later were facing the cavity of the lens vesicle. The proliferative activity was the most intensive in the 6th week, whereas it decreased significantly in the later stages. Additionally, when proliferative activities were compared, the peripheral retina appeared to be less mature than the central before the 9th week. In the earliest analysed stage, cell proliferation might be associated with the sculpturing of the optic cup and stalk, the cornea, and the lens. In the 6th week, the most intensive proliferation seems to be involved not only in the further morphogenesis of the optic cup and the lens vesicle but also in the retinal neurogenesis. At later stages, the decreased proliferation might participate in the neurogenesis of the outer neuroblast zone and the secondary lens fibre formation.

New prognostic factors in uveal melanomas: potential molecular targets for therapy

Even with advances in the diagnosis and local treatment of uveal melanoma, there has been no significant change in the survival rates of these patients in the last decades. Metastatic disease still occurs at the same frequency, and no systemic therapy is currently offered to patients after local eye treatment. Therefore, experimental and clinical research has been focused on the metastatic cascade in order to elucidate its underlying mechanisms at the molecular level. As a result, new prognostic factors in uveal melanoma have been described that also serve as molecular targets for the development of novel treatments. These prognostic factors/molecular targets, such as membrane receptors, enzymes, cytokines, cytoskeleton components, oncogenes, tumour suppressor genes, cell-cycle proteins and nuclear antigens, are reviewed in this article.

How in vitro techniques have increased our understanding of uveal melanoma cellular biology

The past decade has seen a rapid increase in powerful in vitro techniques allowing for the specific study of the biologic properties of tumours. In this review we discuss the role of in vitro studies in providing insight into the biologic mechanisms involved in uveal melanoma. We also review the basis of these studies for the development of adjuvant therapies to aid in the treatment of systemic disease in patients with uveal melanoma.

Bilateral diffuse uveal melanocytic proliferation associated with pancreatic carcinoma: a case report and literature review of this paraneoplastic syndrome

A case of a 64-year-old man with bilateral diffuse uveal melanocytic proliferation is presented. Bilateral diffuse uveal melanocytic proliferation is a rare paraneoplastic disorder where an underlying malignancy causes bilateral blindness by uveal thickening, serous retinal detachment, and rapid cataract formation. The ocular symptoms and signs herald the onset of this disease, which leads to death in most cases within about 1 year. Including the present case, our literature review reveals that a total of 28 cases of bilateral diffuse uveal melanocytic proliferation have now been reported. Several different malignancies have been associated with bilateral diffuse uveal melanocytic proliferation, but ovarian carcinoma in women and lung and suspected pancreatic carcinoma in men are the most common. Our case is the first to be proven at autopsy to be associated with pancreatic carcinoma. The underlying mechanism remains to be identified, as numerous endogenous factors may regulate the proliferation of uveal melanocytes. Consideration of this entity during clinical examination may lead to an earlier diagnosis of malignancy and an improved prognosis.

Proliferation, DNA ploidy, p53 overexpression and nuclear DNA fragmentation in six equine melanocytic tumours

Melanocytic tumours are a well-known clinical and pathological entity in horses, but further phenotypic characterization of these tumours is lacking. Six melanocytic tumours from five horses (two metastatic and four benign) were examined by Ki67, PCNA and p53 immunostaining, DNA nick end labelling (Tunel) and Feulgen staining. The stainings were evaluated using quantitative image analysis. The resulting parameters of growth fraction (Ki67), S-phase index (PCNA), p53 index, apoptotic index, DNA index, nuclear diameter, ploidy balance, proliferation index (Feulgen) and hyperploidy were analysed. The metastatic melanomas showed overexpression of p53 in a large portion of the cells. Apoptosis was also found in the metastatic melanomas. No differences were found in growth fraction, S-phase index (PCNA) nor in DNA configuration between the metastatic and the benign tumours. No immunohistochemical evidence of mutant p53 could be found in the tumours. In conclusion, melanocytic tumours in horses seem to have different phenotypic characteristics in comparison with melanocytic tumours in dogs, cats and humans, especially with respect to proliferative activity of the benign tumours. Therefore, markers put forward in these other species for predicting the clinical behaviour of the melanomas seem to be of no value in the horse. Moreover, quantitative DNA changes or p53 mutations do not seem to be involved in tumourogenesis in these cases.

The prognostic value of cyclin D1, p53, and MDM2 protein expression in uveal melanoma

Malignant uveal melanoma is the commonest primary intraocular tumour in adults. It metastasizes frequently and 50% of patients die within 10 years of diagnosis. The expression of cyclin D1, p53, and MDM2 in uveal melanoma and their relationship to metastasis-free 5-year survival was determined, in order to investigate whether these proteins help to distinguish those patients with a favourable prognosis from those with a poorer one. Ninety-six eyes enucleated for uveal melanomas were immunohistochemically analysed for the protein expression of cyclin D1 and related cell-cycle markers, p53 and MDM2. The evaluation of the specimens was undertaken by two independent pathologists without knowledge of the outcome. Statistical analysis of clinical, morphological, and immunohistological features was performed. A 'favourable outcome' was defined as survival of at least 5 years after diagnosis, without metastases (n=57). An 'unfavourable outcome' was defined as death from metastases within the first 5 years after diagnosis of uveal melanoma (n=39). Cyclin D1 positivity (>15% positive tumour cells) as well as p53 positivity (>15% positive tumour cells) was associated with an unfavourable outcome (for cyclin D1: odds ratio=4. 2, 95% confidence interval 1.5-11.8, p=0.006; for p53: odds ratio=3. 2, 95% confidence interval 1.1-9.3, p=0.03). In addition, cyclin D1 positivity was associated with the presence of extraocular extension of the tumour (p=0.01), with the mixed or epithelioid cell type (p=0. 02), and with the tumour cell MIB-1 positivity (p=0.0001). MDM2 immunoreactivity of the tumour cells showed a potential correlation with clinical outcome (odds ratio=2.1, 95% confidence interval 0.8-5. 8, p=0.13). Multiple logistic regression models showed that cyclin D1 positivity is an independent prognostic factor after control for other prognostic markers. The expression of cyclin D1 in uveal melanoma is associated with a more aggressive course and histologically unfavourable disease. This could serve as a further independent prognostic factor in uveal melanoma.

Effects of proton beam irradiation on uveal melanomas: a comparative study of Ki-67 expression in irradiated versus non-irradiated melanomas

AIMS

To assess the cellular proliferation using the monoclonal antibody Ki-67, in paraffin embedded uveal melanomas irradiated by proton beam, as well as in non-irradiated uveal melanomas.

METHODS

30 enucleated eyes were included for histopathological study and Ki-67 immunostaining. Patients were enucleated between 1991 and 1996 for uveal melanoma, 14 after proton beam irradiation and 16 without treatment (control group). The mean follow up period was 2.5 years after diagnosis and 1 year after enucleation.

RESULTS

A significant relation was found between Ki-67 score and mitotic index (r = 0.56, p = 0.001), histological largest tumour diameter (r = 0.38, p = 0. 03), fibrosis (r = -0.35, p = 0.05), absence of tumoral pigmentation (p = 0.05), and presence of vascular thrombosis (p = 0.03). The Ki-67 score was significantly higher in the non-irradiated group (p = 0.01) and in the group of patients whose cause of enucleation was tumoral evolution (p = 0.005) compared with the group of patients enucleated after neovascular glaucoma. The Ki-67 score was very high in a case of orbital recurrence of uveal melanoma and metastatic death. 70% of metastasised tumours showed a Ki-67 score higher than the median value.

CONCLUSION

Ki-67 labelling is a reliable method of estimating the proliferative activity in uveal melanomas after proton beam irradiation. The Ki-67 score is significantly correlated with prognostic variables (mitotic index and histological largest tumour diameter), and with radiation effects after proton beam irradiation.

The correlation between cell surface markers and clinical features in choroidal malignant melanomas

PURPOSE

Uveal melanoma continues to present problems when attempting to predict disease progression. This study attempts to identify markers indicative of the biological characteristics of cells isolated from samples of uveal melanoma, including adhesion (ICAM-1), immune reactivity (MHC Class I and II), cell cycle control (c-erbB-2, c-myc) and apoptosis control (bcl-2, p53) using dual parameter (DNA/MoAb) flow cytometry.

METHODS

Sixty-three fresh tissue samples from choroidal melanomas were taken at enucleation. Samples were assayed for DNA content and cell cycle, the above antibodies together with positive (PHM-5) and negative (2 degrees FITC Ab) controls. The clinical parameters sex, age, tumour location, cell type, tumour volume and presence of metastases were compared with the results and analysed with the non-parametric Mann-Whitney U-t-test.

RESULTS

ICAM-1 expression proved to be the most clinically relevant, being present on a higher proportion of cells in tumours > 2000 mm3 (median 38, n = 19) compared with the smaller tumours < 2000 mm3 (median 17, n = 26) (p = 0.0015). Metastatic disease was present in 11 patients and did not correlate with any of the surface markers. C-myc, c-erbB-2 and MHC Class II expression were associated with cell type, all showing greater expression in spindle cell tumours than mixed/epithelial types.

CONCLUSION

These results show flow cytometry as a quick, easy method to provide a 'phenotypic profile' for these tumours, and identifies cell cycle control and adhesion molecule expression as important areas for further investigation. c-erbB-2 and bcl-2 positivity was typically seen on over 60% cells in each sample, indicating two potential targets for therapeutic intervention.

Prognostic evaluation of cutaneous malignant melanoma: a clinicopathologic and immunohistochemical study

BACKGROUND AND OBJECTIVES

Depth of invasion and stage of the disease are established prognostic indicators in cutaneous malignant melanoma. The role of other parameters is still an open problem.

METHODS

In 93 consecutive patients with cutaneous malignant melanoma, the level of invasion, tumor thickness, ulceration, vascular invasion, lymphoplasmocytic infiltrates, and mitotic index were evaluated by histology. Expression of Ki-67 and PCNA proliferative antigens together with vimentin, S100, and HMB 45 proteins were assessed by immunohistochemistry.

RESULTS AND CONCLUSIONS

Disease-free and overall survival were correlated with tumor stage, tumor thickness, level of invasion, macroscopic pattern, ulceration, vascular invasion, expression of HMB 45, PCNA, and Ki-67/MIB1. Stage, HMB 45, and PCNA were independent prognostic factors for disease-free survival, whereas tumor stage, tumor thickness, and expression of both proliferative antigens influenced overall survival independently. The variables studied demonstrated reciprocal correlation; therefore, analysis of many prognostic parameters in malignant melanoma could be recommended.

DNA ploidy pattern in choroidal melanoma: correlation with survival. A flow cytometry study on archival material

BACKGROUND/AIMS

Paraffin embedded samples have provided an important source of material for retrospective cytofluorimetric studies, useful in establishing the predictive value of DNA content measurements. The aim of this study was to investigate the incidence and type of aneuploidy in choroidal malignant melanomas (CMM) and the significance in the clinical outcome (median follow up 55 months).

METHODS

DNA content was quantified by flow cytometry in 61 CMM from archival material. Non-tumour ocular tissue was used as the reference diploid standard. Cases in which the coefficient of variation (CV) of the diploid peak was > 8% were excluded. The CMM were classified as spindle A, spindle B, mixed spindle and epithelioid, epithelioid, and necrotic.

RESULTS

The frequency of the aneuploid DNA pattern was 38%. Necrotic tumours showed a worse clinical outcome independent of the ploidy pattern. Spindle A tumours were found to be diploid. Spindle B and mixed tumours showed a prevalent diploid and near diploid aneuploid pattern (DI < 1.3), yet aneuploidy was not correlated with a worse prognosis. The epithelioid tumours were prevalently diploid. However, 83% of the aneuploid tumours were hypodiploid (DI < 0.95), and showed the worst prognosis.

CONCLUSION

These results indicate that increasing DNA abnormalities in CMM, especially in the epithelioid histotype, were associated with an increasing mortality.

MIB-1 and PC-10 immunostaining for the assessment of proliferative activity in primary acquired melanosis without and with atypia

AIMS

To compare the proliferative activity of intraepithelial melanocytes in primary acquired melanosis (PAM) without atypia and PAM with atypia by immunohistochemical staining for the Ki-67 antigen and the proliferating cell nuclear antigen (PCNA).

METHODS

Formalin fixed, paraffin embedded sections from 35 archival specimens of PAM without atypia (n = 19) and with atypia (n = 16) were studied by immunostaining with MIB-1 and PC-10 monoclonal antibodies that react with the Ki-67 antigen and PCNA respectively. The results were calculated as the mean number of positive cells per eyepiece grid. All specimens were evaluated by two masked observers, and the interobserver reproducibility was assessed.

RESULTS

The means of the positive cell count in PAM with atypia were significantly higher compared with PAM without atypia for both observers, in both the PC-10 and the MIB-1 stained sections. In a linear least square model that estimated the interobserver and between group variation, the difference of MIB-1 and PC-10 positive cell count between PAM without and with atypia remained highly significant. The difference between the observers was not significant.

CONCLUSIONS

Immunostaining with MIB-1 and PC-10 demonstrated that PAM with atypia has higher proliferative activity than PAM without atypia. This method was found to be reproducible between different observers.

Prognostic accuracy of the mean of the largest nucleoli, vascular patterns, and PC-10 in posterior uveal melanoma

OBJECTIVE

This study aimed to compare the prognostic value and the predictive accuracy of the PC-10 cell cycling marker with the largest tumor diameter, the mean of the largest nucleoli, and vascular patterns in posterior uveal melanoma.

DESIGN

The study design was a case-control study.

PARTICIPANTS

Eyes enucleated for posterior uveal melanoma from patients who either died of metastatic melanoma or survived without signs of metastatic disease 10 years or more after surgery were studied.

INTERVENTION

Three observers assessed the above prognostic indicators and standard histopathologic characteristics from microslides without access to survival data.

MAIN OUTCOME MEASURES

Univariate and multivariate Cox models for survival were constructed, and a multiparameter prognostic index was calculated for each patient, based on covariates obtained from the final Cox model. The prognostic accuracy was determined by receiver operating characteristic curve analysis.

RESULTS

The log PC-10 count, vascular networks, mean of the largest nucleoli, largest tumor diameter, age of patient, and prognostic index were independently associated with outcome. However, each of these indicators had no more than a poor-to-moderate predictive accuracy, and only the prognostic index was significantly better than the largest tumor diameter.

CONCLUSIONS

The PC-10 count retains a prognostic value in uveal melanoma when adjusting for the effect of the mean of the largest nucleoli and diverse vascular patterns. A prognostic index combining two or more indicators may improve the predictive precision.

Ploidy Analysis and Ki-67 Expression in Myelodysplastic Syndromes

BACKGROUND

The Myelodysplastic Syndromes (MDS) are disorders involving clonal proliferative activity in the bone marrow that can lead to marrow failure and acute leukemia. This study was undertaken to evaluate the relationships between clinical factors, type of MDS, DNA ploidy, and Ki-67 expression.

DESIGN

Air-dried bone marrow smears from 27 patients were Feulgen stained for DNA and analyzed using the CAS 200 image analyzer. Ki-67 expression was also examined by image analysis in 25 of these cases in bone marrow core biopsy specimens using the monoclonal antibody MIB-1. Age, sex, bone marrow cellularity, and MDS grade of each patient were also recorded. Percent S-phase was assessed only for the diploid samples.

RESULTS

There were 16 diploid and 11 aneuploid cases on analysis of Feulgen-stained bone marrow aspirate smears. The percentage of MIB-1+ cells ranged from 6.4%-61.7% (mean-37.7 ± 6.4%). Among the 16 diploid cases, 18.2 ± 5.7% of the cells were in S-phase. High grade MDS (RAEB-T, RAEB, CMML) was associated with younger age and male sex (p = 0.03), lower percentage of cells in S-phase (p = 0.04), greater bone marrow cellularity (p = 0.005), and greater MIB-1 expression (p = 0.04). With increasing age, there were more females (p = 0.03), more low grade MDS (RA, RARS), and a lower percentage of cells in S-Phase (p = 0.04). Female patients tended to be older, have less cellular bone marrows (p = 0.003), less MIB-1 expression (p = 0.03), low grade MDS (p = 0.02), and increased percentage of cells in S phase (p = 0.008).

CONCLUSION

Ki-67 expression, percent cells in S-phase, clinical parameters and subtype of MDS tend to distinguish two separate groups of MDS patients, and may explain in part the difference in biologic behaviour between high and low grade MDS.