In vivo monosomy 3 detection of posterior uveal melanoma: 3-year follow-up

Primary vitreoretinal involvement and immunopositivity for BRAFV600E help distinguish metastatic from primary intraocular melanoma: a detailed histopathologic study of metastatic cutaneous melanoma to the eye

OBJECTIVE

To evaluate the clinicopathologic characteristics of metastatic cutaneous melanoma to the eye and identify potential distinguishing characteristics from the more common primary uveal melanoma; particularly, tumour location within the eye, cytomorphology and immunohistochemical/specific molecular genetic features.

METHODS

A retrospective observational case series using surgical enucleation and diagnostic vitrectomy cytologic specimens from seven patients with suspected intraocular melanoma, eventually diagnosed as metastatic melanoma, was conducted. Haematoxylin and eosin-stained sections of tumour and immunohistochemical (IHC) stains for BRAFV600E and Ki-67 were critically reviewed; BAP1 IHC was also evaluated in cases where additional tissue was available. Clinical imaging studies and medical records were reviewed.

RESULTS

The majority of patients (86%) with metastatic melanoma have primary vitreoretinal (not uveal) involvement and epithelioid, highly malignant cytomorphology (100%); many (50%) harbour BRAFV600E mutations, a finding not seen in large cohorts of primary uveal melanoma.

CONCLUSIONS

Characteristics favouring or defining metastatic intraocular melanoma over primary uveal melanoma include high-grade epithelioid cytology, predominant involvement of the vitreous cavity and/or retina, and presence of positive immunostaining for BRAFV600E.

Genetic prognostication in uveal melanoma

Uveal melanoma (UM) is a rare tumour with a high propensity to metastasize. Although no effective treatment for metastases yet exists, prognostication in UM is relevant for patient counselling, planning of follow-up and stratification in clinical trials. Besides conventional clinicopathologic characteristics, genetic tumour features with prognostic significance have been identified. Non-random chromosome aberrations such as monosomy 3 and gain of chromosome 8q are strongly correlated with metastatic risk, while gain of chromosome 6p indicates a low risk. Recently, mutations in genes such as BAP1, SF3B1 and EIF1AX have been shown to be related to patient outcome. Genetics of UM is a rapidly advancing field, which not only contributes to the understanding of the pathogenesis of this cancer, but also results in further refinement of prognostication. Concomitantly, advances have been made in the use of genetic tests. New methods for genetic typing of UM have been developed. Despite the considerable progress made recently, many questions remain, such as those relating to the reliability of prognostic genetic tests, and the use of biopsied or previously irradiated tumour tissue for prognostication by genetic testing. In this article, we review genetic prognostic indicators in UM, also comparing available genetic tests, addressing the clinical application of genetic prognostication and discussing future perspectives for improving genetic prognostication in UM.

Brachytherapy for patients with uveal melanoma: historical perspectives and future treatment directions

Surgical management with enucleation was the primary treatment for uveal melanoma (UM) for over 100 years. The Collaborative Ocular Melanoma Study confirmed in 2001 that globe-preserving episcleral brachytherapy for UM was safe and effective, demonstrating no survival difference with enucleation. Today, brachytherapy is the most common form of radiotherapy for UM. We review the history of brachytherapy in the treatment of UM and the evolution of the procedure to incorporate fine-needle-aspiration biopsy techniques with DNA-and RNA-based genetic prognostic testing.

Yield, Techniques, and Complications of Transvitreal and Transscleral Biopsies in Small Uveal Melanoma

Importance

Intraoperative adequacy check of biopsy samples can lead to a higher biopsy yield rate, and subsequent genomic analysis can provide patients with valuable prognostic information.

Objectives

To examine the yield rates for transscleral and transvitreal fine-needle aspiration biopsies of small uveal melanoma less than 3.6 mm in apical height and to discuss techniques that would maximize yield rates and minimize complications.

Design, Setting, and Participants

A retrospective, consecutive observational case series was conducted from January 29, 2013, to May 23, 2017, at Retina Consultants of Houston and Houston Methodist Hospital among 44 patients with uveal melanoma of the ciliary body or choroid.

Interventions or Exposures

Fine-needle aspiration biopsy and intraoperative histopathologic analysis prior to iodine 125 brachytherapy.

Main Outcomes and Measures

Tumor locations and dimensions were identified by histopathologic analysis and B-scan ultrasonography. Either transscleral or transvitreal biopsy was performed for tumors anterior to the equator and posterior to the equator, respectively. Biopsy specimens were checked for adequacy intraoperatively. Specimens were examined using hematoxylin-eosin, double immunostain with human melanoma black 45 and Ki67, and gene expression profile.

Results

A total of 44 patients were included in the study, with a mean (SD) age of 63.3 (12.7) years (21 men [47.7%]; 23 women [52.3%]). Median tumor height was 2.7 mm (interquartile range, 2.3- 2.9 mm). Forty of 44 biopsy samples (90.9%; 95% CI, 82.4%-99.4%) yielded adequate cells for gene expression profile analysis. Transscleral and transvitreal yield rates were 11 of 11 (100%) and 29 of 33 (87.9%), respectively. Most localized vitreous hemorrhages were resolved by 3 months. There was a moderate association between localized vitreous hemorrhage and transvitreal biopsy method, for which the phi value was -0.526 (95% CI, -0.712 to -0.157; P < .001).

Conclusions and Relevance

These findings suggest intraoperative adequacy evaluation of fine-needle aspiration biopsy specimens leads to high yield and is more informative for patients.

Histopathologic Analysis of Transvitreal Fine Needle Aspiration Biopsy Needle Tracts for Uveal Melanoma

PURPOSE

Perform the first in vivo examination of fine needle aspiration biopsy (FNAB) scleral tracts to determine the incidence of iatrogenic extension of tumor cells.

DESIGN

A prospective, consecutive, observational case series.

METHODS

This study was performed in a clinical/surgical setting at Retina Consultants of Houston and Houston Methodist Hospital, Houston, Texas, and included 10 patients who were scheduled for enucleation as primary treatment for uveal melanoma. Treatment included FNAB, enucleation, and histopathologic analysis. The primary outcomes were tumor location and dimension as identified by B-scans and histopathologic analysis. Tumor type was classified by gene expression profile and American Joint Committee on Cancer staging. Twenty-five- or 27-gauge needles were used for FNAB under direct visualization. Cell blocks of acquired specimens were examined using hematoxylin-eosin stain and double immunostain using HMB45 with red chromogen and Ki67 with brown 3,3'-diaminobenzidine chromogen.

RESULTS

Mean follow-up after enucleation was 20.4 months (range 9.9-31.7). All biopsy specimens had adequate yields for genomic analysis. No enucleation specimen contained tumor cells within sclera, pars plana, or pars plicata. One specimen contained a small collection of tumor cells within the anterior vitreous in the quadrant of the biopsy site. No patient developed an orbital recurrence. Four patients developed nonorbital metastatic uveal melanoma during the study period. Three of them died, and 1 is alive with hepatic metastasis.

CONCLUSIONS

No iatrogenic extension of tumor was reported. FNAB is a safe procedure that produces a high cellular yield for cytologic and genomic analyses with minimal risk of extraocular dissemination.

Uveal melanoma: An analysis of cellular features and comparison to monosomy 3 status

BACKGROUND

Choroidal and ciliary body melanomas divide into two approximately equal groups. Local therapy cures one group while the other metastasizes and proves lethal. Monosomy 3 strongly associates with aggressive behavior. We analyzed a series of choroidal and ciliary body melanomas to describe the cellular features and to compare them to monosomy 3 status using the latter as a surrogate for survival.

METHODS

One hundred eleven specimens met the study's inclusion criteria. Following ThinPrep processing, samples were analyzed for cellular features including: cell type, nuclear grade, tumor infiltrating lymphocytes, and the presence of necrosis and melanin. FISH analysis for monosomy 3 was performed on ThinPrep slides using a threshold of 20% monosomic cells per 200 melanoma cells.

RESULTS

Seventy-two tumors (65%) had a mixed cell type while spindle cell type and epithelioid cell type occurred in 37 (33%) and 2 (1.8%), respectively. Seventy-five tumors (68%) had Grade 2 nuclear atypia. Monosomy 3 occurred in 57 tumors (51%). Significantly more tumors with Grade 3 nuclei had monosomy 3 (79% vs.43%, P = 0.002) and metastases (29% vs. 8%, P = 0.01). None of the 11 pure spindle cell tumors with Grade 1 nuclei metastasized or had monosomy 3.

CONCLUSIONS

Uveal melanoma has a relatively consistent cellular appearance, characterized by a mixed cell pattern and no more than moderate nuclear atypia. This consistent appearance aids in the cellular diagnosis but limits prognostication using cellular features. Cellular features significantly associate with monosomy 3 status only in the minority of tumors at the extremes of the morphologic spectrum.

Fine Needle Aspiration Biopsy in Uveal Melanoma: Technique, Complications, and Outcomes

PURPOSE

To report the technical aspects, complications, and outcomes concerning fine needle aspiration biopsy (FNAB) in uveal melanoma.

DESIGN

Retrospective cohort study.

METHODS

Patients with uveal melanoma who underwent transscleral or transvitreal FNAB at an ocular oncology center were retrospectively evaluated. FNAB was performed if the tumor was more than 5 mm in thickness. Array comparative genomic hybridization analysis was performed on biopsy samples with sufficient tissue. The main outcome measures were success (sample that gave a successful result for biomarker analysis) rate, complications, liver metastasis, and overall survival.

RESULTS

There were 217 (114 male, 52%) consecutive study patients with a mean age of 56.7 (16-84) years. The mean follow-up period was 31 (range 3.6-61.3) months. Mean tumor thickness was 8.4 (range 5-12) mm. The overall success rate of the procedure was 169 patients (77.9%). Thirty-one patients (14.3%) experienced intravitreal hemorrhage, of whom 9 (4.1%) required vitreal surgery. There was no case of endophthalmitis, orbital dissemination, local recurrence, or rhegmatogenous retinal detachment. Thirty-two patients (14.7%) developed metastasis during the study, of whom 20 (9.2%) died. Of the 169 successful samples, 53 patients (31%) were classified as low risk, 41 (24%) as intermediate risk, and 54 (32%) as high risk. Fifteen patients (9%) did not have any detectable chromosomal abnormality and 6 (4%) could not be classified.

CONCLUSION

FNAB is a relatively safe and successful technique that can be routinely used to obtain tissue for molecular genomic analysis; such analysis helps determine the diagnosis and prognosis in uveal melanoma.

Development and external validation of a prognostic nomogram for metastatic uveal melanoma

Background

Approximately 50% of patients with uveal melanoma (UM) will develop metastatic disease, usually involving the liver. The outcome of metastatic UM (mUM) is generally poor and no standard therapy has been established. Additionally, clinicians lack a validated prognostic tool to evaluate these patients. The aim of this work was to develop a reliable prognostic nomogram for clinicians.

Patients and Methods

Two cohorts of mUM patients, from Veneto Oncology Institute (IOV) (N=152) and Mayo Clinic (MC) (N=102), were analyzed to develop and externally validate, a prognostic nomogram.

Results

The median survival of mUM was 17.2 months in the IOV cohort and 19.7 in the MC cohort. Percentage of liver involvement (HR 1.6), elevated levels of serum LDH (HR 1.6), and a WHO performance status=1 (HR 1.5) or 2–3 (HR 4.6) were associated with worse prognosis. Longer disease-free interval from diagnosis of UM to that of mUM conferred a survival advantage (HR 0.9). The nomogram had a concordance probability of 0.75 (SE .006) in the development dataset (IOV), and 0.80 (SE .009) in the external validation (MC). Nomogram predictions were well calibrated.

Conclusions

The nomogram, which includes percentage of liver involvement, LDH levels, WHO performance status and disease free-interval accurately predicts the prognosis of mUM and could be useful for decision-making and risk stratification for clinical trials.

Sufficiency of FNAB aspirates of posterior uveal melanoma for cytologic versus GEP classification in 159 patients, and relative prognostic significance of these classifications

Objective

To determine the relative sufficiency of paired aspirates of posterior uveal melanomas obtained by FNAB for cytopathology and GEP, and their prognostic significance for predicting death from metastasis.

Methods

Prospective non-randomized IRB-approved single-center longitudinal clinical study of 159 patients with posterior uveal melanoma sampled by FNAB in at least two tumor sites between 09/2007 and 12/2010. Cases were analyzed with regard to sufficiency of the obtained aspirates for cytopathologic classification and GEP classification. Statistical strength of associations between variables and GEP class was computed using Chi-square test. Cumulative actuarial survival curves of subgroups of these patients based on their cytopathologic versus GEP-assigned categories were computed by the Kaplan–Meier method. The endpoint for this survival analysis was death from metastatic uveal melanoma.

Results

FNAB aspirates were insufficient for cytopathologic classification in 34 of 159 cases (21.9 %). In contrast, FNAB aspirates were insufficient for GEP classification in only one of 159 cases (0.6 %). This difference is statistically significant (P < 0.001). Six of 34 tumors (17.6 %) that yielded an insufficient aspirate for cytopathologic diagnosis were categorized as GEP class 2, while 43 of 125 tumors (34.7 %) that yielded a sufficient aspirate for cytopathologic diagnosis were categorized as GEP class 2. To date, 14 of the 49 patients with a GEP class 2 tumor (28.6 %) but only five of the 109 patients with a GEP class 1 tumor (5.6 %) have developed metastasis. Fifteen of 125 patients (12 %) whose tumors yielded sufficient aspirates for cytopathologic classification but only four of 34 patients (11.8 %) whose tumors yielded insufficient aspirates for cytopathologic classification developed metastasis. The median post-biopsy follow-up time for surviving patients in this series was 32.5 months. Cumulative actuarial 5-year probability of death from metastasis 14.1 % for those with an insufficient aspirate for cytopathologic classification versus 22.4 % for those with a sufficient aspirate for cytopathologic classification (log rank P = 0.68). In contrast, the cumulative actuarial 5-year probability of metastatic death was 8.0 % for those with an insufficient/unsatisfactory aspirate for GEP classification or GEP class 1 tumor, versus 45.0 % for those with a GEP class 2 tumor (log rank P = 0.005).

Conclusion

This study confirmed that GEP classification of posterior uveal melanoma cells obtained by FNAB is feasible in almost all cases, including most in which FNAB yields an insufficient aspirate for cytodiagnosis. The study also confirmed that GEP classification is substantially better than cytologic classification for predicting subsequent metastasis and metastatic death.

A review of advanced genetic testing for clinical prognostication in uveal melanoma

Uveal melanoma (UM) has a strong propensity to metastasize and the prognosis for metastatic disease is very poor. It has been suggested that occult micrometastases are already present, but undetectable, in many patients at the time when the primary ocular tumor is diagnosed and treated. To identify high-risk patients for close monitoring and early intervention with prophylactic adjuvant systemic therapy, an accurate predictive system is necessary for stratifying those patients at risk of developing metastatic disease. To date, many clinical and histopathological features, molecular pathway characteristics, and genetic fingerprints of UM have been suggested for disease prognostication. Among the newest of them, tumor genetics has received the most attention in demonstrating promise as a prognostic tool. Because of the plethora of recent developments, we summarize and compare in this review the important standard and more advanced cytogenetic prognostic markers. We further describe the variety of genetic tests available for prognostication of UM, and provide a critical assessment of the respective advantages and disadvantages of these tools.

Transretinal uveal melanoma biopsy with 25-gauge vitrectomy system

PURPOSE

To evaluate the efficacy and the safety of uveal melanoma transretinal biopsy using 25-gauge vitrectomy system.

METHODS

At the patient's request of a tissue diagnosis, nine posterior uveal melanomas treated by proton-beam therapy were biopsied during the insertion of tantalium markers.

RESULTS

The diagnosis was uveal melanoma, confirmed in all cases using cytological (7 of 9) and histological analysis (2 of 9). Immunocytochemistry was performed on all samples (9 of 9). In eight of nine patients, minor postoperative vitreous haemorrhages were seen, which resolved in 1 day. No other ocular complications were noticed.

CONCLUSION

Uveal melanoma biopsy using 25-gauge vitrectomy system is a valuable procedure to confirm the diagnosis, with adequate sample and low ocular morbidity.

Chromosome 3 status in uveal melanoma: a comparison of fluorescence in situ hybridization and single-nucleotide polymorphism array

PURPOSE

To compare fluorescence in situ hybridization (FISH) using a centromeric probe for chromosome 3 (CEP3) and 3p26 locus-specific probe with single-nucleotide polymorphism array (SNP-A) analysis in the detection of high-risk uveal melanoma.

METHODS

Fifty cases of uveal melanoma (28 males, 22 females) treated by enucleation between 2004 and 2010 were analyzed. Fresh tissue was used for FISH and SNP-A analysis. FISH was performed using a CEP3 and a 3p26 locus-specific probe. Tumor size, location, and clinical outcome were recorded during the 7-year study period (median follow-up: 35.5 months; mean: 38.5 months). The sensitivity, specificity, positive predictive value, and negative predictive value were calculated.

RESULTS

Monosomy 3 was detected by FISH-CEP3 in 27 tumors (54%), FISH-3p26 deletion was found in 30 (60%), and SNP-A analysis identified 31 (62%) of the tumors with monosomy 3. Due to technical failures, FISH and SNP-A were noninterpretable in one case (2%) and two cases (4%), respectively. In both cases of SNP-A failure, tumors were positive for FISH 3p26 deletion and in a single case of FISH failure, monosomy 3 was found using SNP-A. No statistically significant differences were observed in any of the sensitivity or specificity measures.

CONCLUSIONS

For prediction of survival at 36 months, FISH CEP3, FISH 3p26, and SNP-A were comparable. A combination of prognostication techniques should be used in an unlikely event of technical failure (2%-4%).

Monosomy 3 by FISH in uveal melanoma: variability in techniques and results

Tumor monosomy 3 confers a poor prognosis in patients with uveal melanoma. We critically review the techniques used for fluorescence in situ hybridization (FISH) detection of monosomy 3 in order to assess variability in practice patterns and to explain differences in results. Significant variability that has likely affected reported results was found in tissue sampling methods, selection of FISH probes, number of cells counted, and the cut-off point used to determine monosomy 3 status. Clinical parameters and specific techniques employed to report FISH results should be specified so as to allow meta-analysis of published studies. FISH-based detection of monosomy 3 in uveal melanoma has not been performed in a standardized manner, which limits conclusions regarding its clinical utility. FISH is a widely available, versatile technology, and when performed optimally has the potential to be a valuable tool for determining the prognosis of uveal melanoma.

Descriptive epidemiology of malignant mucosal and uveal melanomas and adnexal skin carcinomas in Europe

This work provides descriptive epidemiological data of malignant mucosal and uveal melanomas and adnexal skin carcinomas in Europe as defined as in the RARECARE project. We analysed 8669 incident cases registered in the period 1995-2002 by 76 population-based cancer registries (CRs), and followed up for vital status to 31st December 2003. Age-standardised incidence to the European standard population was obtained restricting the analysis to 8416 cancer cases collected by 64 not specialised CRs or with information available only for some anatomical sites. Period survival rates at 2000-2002 were estimated on 45 CRs data. Twenty-two CRs which covered the period 1988-2002 were analysed to obtain the 15-year prevalence (1st January 2003 as reference date). Complete prevalence was calculated by using the completeness index method which estimates surviving cases diagnosed prior to 1988 ('unobserved' prevalence). The expected number of new cases per year and of prevalent cases in Europe was then obtained multiplying the crude incidence and complete prevalence rates to the European population at 2008. We estimated 5204 new cases per year (10.5 per million) to occur in Europe, of which 48.7% were melanomas of uvea, 24.8% melanomas of mucosa and 26.5% adnexal carcinomas of the skin. Five-year relative survival was 40.6% and 68.9% for mucosal and uveal melanomas, respectively. Adnexal skin carcinomas showed a good prognosis with a survival of 87.7% 5 years after diagnosis. Northern Europe, United Kingdom (UK) and Ireland showed the highest 5-year survival rate for uveal melanomas (72.6% and 73.4%), while Southern Europe showed the lowest rate (63.7%). More than 50,000 persons with a past diagnosis of one of these rare cancers were estimated to be alive at 2008 in Europe, most of them (58.8%, n=29,676) being patients with uveal melanoma. Due to the good prognosis and high incidence of uveal melanomas, these malignancies are highly represented among the long-term survivors of the studied rare cancer types. Therefore, maximising quality of life is particularly important in treatment of uveal melanoma. As regards mucosal melanomas, the centralisation of treatment to a select number of specialist centres as well as the establishment of expert pathology panels should be promoted. The geographical differences in incidence and survival should be further investigated analysing the centre of treatment, the stage at diagnosis and the treatment.

Circulating tumor cells in uveal melanoma

Despite advances in the diagnosis and local tumor control, the overall mortality rate for uveal melanoma remains high because of the development of metastatic disease. The clinical and histopathological systems currently being used to classify patients are not sufficiently accurate to predict metastasis. Tumor genotyping has demonstrated significant promise but obtaining tumor tissue can be problematic. Furthermore, assessment of tumor tissue does not indicate whether tumor cells have actually been shed and cannot indicate whether treatment is reducing metastasis. The detection of circulating tumor cells in blood has been shown to be a prognostic biomarker that can be used to monitor the effectiveness of therapy in patients with metastatic carcinoma. Uveal melanoma disseminates hematogenously, and the detection of circulating melanoma cells may potentially be useful for diagnosis, risk stratification, and the monitoring of disease progression and treatment efficacy. PCR-based and immunomagnetic cell isolation techniques, derived from studies in patients with cutaneous melanoma, have been tested. For various biological and technical reasons, they have not demonstrated the accuracy and reproducibility required for an effective prognostic assay in patients with uveal melanoma. Assessments have been confounded by false positives and negatives and thus, correlations between circulating melanoma cells and survival have not yet been established. Circulating melanoma cell detection is a valuable tool for investigating metastasis in uveal melanoma and also has the potential to become a standard part of uveal melanoma management. However, more research on the biology of uveal melanoma as well as improvements upon the current technologies are needed.

[Genomic techniques used in uveal melanoma: a literature review]

Genome study and expression profiling of the tumor seem to be the most significant biologic prognostic factor in uveal melanoma. Many cytogenetic and molecular tests are reported; our aim was to assess their ability to detect high metastatic risk patients through a literature review. Standard karyotyping, fluorescence in situ hybridization and microsatellite analysis are not adequate. DNA-based genome techniques must analyse the entire genome (comparative genomic hybridization [CGH]) and, optimally, detect chromosome 3 isodisomy ("single-nucleotid polymorphism" SNP-array). Multiplex ligation-dependent probe amplification (MLPA) is less expensive than array-CGH, but its interpretation may be delicate. Gene expression profiling is the most accurate molecular test for predicting metastatic death in patient with uveal melanoma even if it remains a costly technique. These prognostic tests could be useful to identify high-risk patients in future adjuvant therapy protocols.

Modified enucleation for choroidal melanoma with large extrascleral extension

PURPOSE

To report the technique and the outcome of modified (enlarged) enucleation via lateral orbitotomy for choroidal melanomas with massive extrascleral extension.

METHODS

5 patients with choroidal malanoma with massive, circumscribed perioptic/posterior extrascleral extension underwent modified enucleation via lateral orbitotomy. After lateral orbitotomy and orbital mass exposure with direct tumor visualization, a long optic nerve stump was cut and the orbital component of the tumor was completely (macroscopically) removed along with the globe in all cases. After haemostasis and orbital reconstruction an orbital implant was then placed. Follow-up was longer than 12 months.

RESULTS

Excellent cosmetic outcome was acheived in all patients (100%) without operative or postoperative complications. At pathologic examination, tumors were completely removed in all cases (100%).

CONCLUSIONS

Modified (enlarged) enucleation via lateral orbitotomy for selectd choroidal melanomas with massive, circumscribed perioptic/posterior extrascleral extension allows complete tumor removal and placement of an orbital implant, avoiding the long healing process of orbital exenteration with excellent clinical and cosmetic outcome.

Fine-needle aspiration biopsy and other biopsies in suspected intraocular malignant disease: a review

Ocular oncologists require a strong indication for intraocular biopsy before the procedure can be performed because it carries a risk for serious eye complications and the dissemination of malignant cells. The purpose of this review is to evaluate the extent to which this restricted practice is supported by evidence from previous reports and to outline our main indications and contraindications. The different intraocular biopsy techniques in the anterior and posterior segment are discussed with a focus on our preferred method, fine-needle aspiration biopsy (FNAB). In the literature, complications are typically under-reported, which reduces the possibilities of evaluating the risks correctly and of making fair comparisons with other biopsy methods. In FNAB, the exact placement of the needle is critical, as is an accurate assessment of the size of the lesion. Fine-needle aspiration biopsy is usually not a reliable diagnostic tool in lesions < 2 mm in thickness. It is very advantageous to have a cytopathologist present in the operating theatre or close by. This ensures adequate sampling and encourages repeated biopsy attempts if necessary. This approach reduces false negative results to < 3%. Adjunct immunocytochemistry is documented to increase specificity and is essential for diagnosis and management in about 10% of cases. In some rare pathological processes the diagnosis depends ultimately on the identification of specific cell markers. An accurate diagnosis may have a decisive influence on prognosis. The cytogenetic prognostications made possible after FNAB are reliable. Biopsy by FNA has a low complication rate. The calculated risk for retinal detachment is < 4%. Intraocular haemorrhage is frequently observed, but clears spontaneously in nearly all cases. Only a single case of epibulbar seeding of malignant cells at the scleral pars plana puncture site of transvitreal FNAB has been documented. Endophthalmitis has been reported and adequate standard preoperative preparation is obligatory. An open biopsy is still an option in the anterior segment, but has been abandoned in the posterior segment. Although vitrectomy-based procedures are becoming increasingly popular, we recommend using FNAB as part of a stepwise approach. A vitrectomy-assisted biopsy should be considered in cases where FNAB fails. In any adult patient with suspected intraocular malignancy in which enucleation is not the obvious treatment, the clinician should strive for a diagnosis based on biopsy. When the lesion is too small for biopsy or the risks related to the procedure are too great, it is reasonable to be reluctant to biopsy. The standards applied in the treatment of intraocular malignant diseases should be equivalent to those in other fields of oncology. Our view is controversial and contrary to opinion that supports current standards of care for this group of patients.

Expression of the SST receptor 2 in uveal melanoma is not a prognostic marker

INTRODUCTION

Uveal melanoma (UM) cells and neurohormone-producing cells both originate from the neural crest. Somatostatin receptors subtype 2 (SSTR2) are over-expressed in several tumors, often from neuroendocrine origin, and synthetic antagonists like octreotide and octreotate are being used as diagnostic or therapeutic agents. We investigated the SSTR2 expression in UM, and determined whether this expression was related to prognosis of the disease.

MATERIALS AND METHODS

UM cell lines and fresh primary UM samples were tested for SSTR2 expression by autoradiography (AR) using 125I-Tyr3-octreotate. Furthermore, UM cell lines were analyzed for SSTR2 mRNA expression with quantitative real-time RT-PCR.

RESULTS

Using AR, cell-surface SSTR2 expression was demonstrated in two UM metastatic cell lines, but no expression was detected in three cell lines derived from primary UM. However, all primary and metastatic UM cell lines showed mRNA expression levels for SSTR2 using quantitative real-time RT-PCR. Only three of 14 primary UM demonstrated moderate SSTR2 expression, and this expression was not significantly associated with tumor-free survival or any tested prognostic factor.

CONCLUSIONS

Based on the rare and low expression of SSTR2 found in primary UM specimens and in UM cell lines, we conclude that SSTR2 is not widely expressed in UM. Furthermore, SSTR2 expression was not associated with tumor-free survival and prognostic factors. Therefore SSTR2 is not suited as prognostic marker or therapeutic target in UM.