Facteurs pronostiques du mélanome malin de l’uvée

Tebentafusp for the treatment of metastatic uveal melanoma

Uveal melanoma is a rare disease; nevertheless, it is the most common primary intraocular malignancy among adults. Approximately half of affected patients will suffer from metastatic disease, mostly to the liver. No standard-of-care treatment exists for these patients. Median progression-free survival and overall survival for all types of treatment, including checkpoint inhibitors, have remained poor. However, the most recent phase III study results for tebentafusp, a member of a new-in-class molecule, are raising hopes for stage IV uveal melanoma patients. In this review, we examine the current literature, focusing on the most recent trial results for this new reagent. We evaluate the latest clinical results for tebentafusp and aim to shed light on its immunological strategy.

Association of Partial Chromosome 3 Deletion in Uveal Melanomas With Metastasis-Free Survival

Importance

Studies on uveal melanomas (UMs) have demonstrated the prognostic value of 8q gain and monosomy 3, but the prognosis of UMs with partial deletion of chromosome 3 remains to be defined.

Objective

To examine the association of partial chromosome 3 deletion in UMs with metastasis-free survival.

Design, Setting, and Participants

This retrospective cohort study of 1088 consecutive comparative genomic hybridization arrays performed from May 1, 2006, to July 31, 2015, assessed patients presenting with UMs with and without partial loss of chromosome 3 at a referral center. Data analysis was performed from September 1, 2017, to November 30, 2017.

Exposure

Uveal melanoma with or without partial loss of chromosome 3.

Main Outcomes and Measures

Metastasis-free survival and overall survival at 60 months.

Results

Of the 1088 consecutive comparative genomic hybridization arrays that were performed, 43 UMs (4.0%) in 43 patients (median age, 58 years [range, 12-79 years]; 22 [51%] female) carried partial deletions of chromosome 3. Median follow-up was 66 months (range, 1.2-126.2 months). Metastasis-free survival at 60 months was 33.6% (95% CI, 15.8%-71.4%) for UMs that carried a deletion of the BAP1 (BRCA1 associated protein 1) locus (BAP1del; 24 tumors) and 80.5% (95% CI, 64.8%-100%) for UMs without the loss of the BAP1 locus (BAP1 normal [BAP1nl]; 19 tumors) (log-rank P = .001). Overall survival at 60 months was 64.5% (95% CI, 43.5%-95.8%) in the BAP1del group vs 84.1% (95% CI, 69.0%-100%) in the BAP1nl group (log-rank P < .001). In these 43 cases, metastasis-free survival at 60 months was 100% for UMs without loss of the BAP1 locus or 8q gain, 70.0% (95% CI, 50.5%-96.9%) for UMs that carried 1 of these alterations, and 12.5% (95% CI, 2.1%-73.7%) for those that carried both (log-rank P < .001). Similarly, overall survival at 60 months was 100% for UMs without loss of the BAP1 locus or 8q gain, 80.8% (95% CI, 63.3%-100%) for UMs that carried 1 of these alterations, and 46.7% (95% CI, 23.3%-93.6%) for those that carried both (log-rank P < .001).

Conclusions and Relevance

These findings suggest that partial deletion of chromosome 3 encompassing the BAP1 locus is associated with poor prognosis. A cytogenetic classification of UMs could be proposed based on the status of the BAP1 locus instead of the chromosome 3 locus, while also taking chromosome 8q into account.

Immunotherapies for the Treatment of Uveal Melanoma-History and Future

Background: Uveal melanoma is the most common primary intraocular malignancy among adults. It is, nevertheless, a rare disease, with an incidence of approximately one case per 100,000 individuals per year in Europe. Approximately half of tumors will eventually metastasize, and the liver is the organ usually affected. No standard-of-care treatment exists for metastasized uveal melanoma. Chemotherapies or liver-directed treatments do not usually result in long-term tumor control. Immunotherapies are currently the most promising therapy option available. Methods: We reviewed both relevant recent literature on PubMed concerning the treatment of uveal melanoma with immunotherapies, and currently investigated drugs on ClinicalTrials.gov. Our own experiences with immune checkpoint blockers are included in a case series of 20 patients. Results: Because few clinical trials have been conducted for metastasized uveal melanoma, no definitive treatment strategy exists for this rare disease. The outcomes of most immunotherapies are poor, especially compared with cutaneous melanoma. However, encouraging results have been found for some very recently investigated agents such as the bispecific tebentafusp, for which a remarkably increased one-year overall survival rate, and similarly increased disease control rate, were observed in early phase studies. Conclusions: The treatment of metastatic uveal melanoma remains challenging, and almost all patients still die from the disease. Long-term responses might be achievable by means of new immunological strategies. Patients should therefore be referred to large medical centers where they can take part in controlled clinical studies.

Prospective study of surveillance testing for metastasis in 100 high-risk uveal melanoma patients

Despite advances in the local treatment of UM, half of patients develop metastases typically to the liver with poor survival. Microscopic complete surgical resection (R0) of liver metastases improves survival in high selected patients. Early identification of high-risk patients might allow detection of asymptomatic metastases, and increase R0 liver surgery rate. From October 2006 to December 2009, we conducted a prospective study to detect early minimal lesions with 6-monthly liver function tests (LFTs) and liver MRI in 100 high-risk patients. High risk was defined by primary tumor clinical or genomic criteria: thickness>8mm or diameter>15 mm, or extra-scleral extension, or monosomy 3 by FISH or aCGH. With a median follow-up of 49 months, the 5-year metastasis-free survival and overall survival were 47 and 33%, respectively. Of the 60 patients who became metastatic, 50 (83%) had exclusive liver metastasis. LFTs screening had no sufficient accurary, but biannual MRI showed high predictive value to detect metastasis and select patients eligible for curative surgery: 25/50 underwent laparotomy and among them, 8/25 (32%) had a R0 surgery. Median survival after metastasis was 14 months, mean survival reached 40 months in the R0 resected population. Six-monthly liver MRI screening is recommended in patients with large tumors or genomic high risk in order to detect early patient candidates to complete resection of liver metastases.

Prognostic value of legumain in uveal melanoma

The present study aimed to assess the expression of legumain in uveal melanoma (UM) cell lines and primary UM specimens, and to determine the possible association between legumain expression and clinical as well as pathological characteristics to reveal its impact on the prognosis of patients with UM. Records of primary UM cases treated at Beijing Tongren Hospital and Tianjin Eye Hospital between 1996 and 2005 were retrieved for analysis and a total of 82 patients with uveal melanoma were included in the study. The expression of legumain in the formalin-fixed and paraffin-embedded surgical specimens of these 82 patients was determined using immunohistochemical analysis. In addition, the expression of legumain was examined in two uveal melanoma cell lines using polymerase chain reaction and western blot analyses. The association of legumain expression with clinical/pathological characteristics was analyzed using the χ² and Fisher's exact test. In addition, the impact of legumain on the prognosis of patients with uveal melanoma was examined. Upregulation of legumain was more predominant in the highly invasive uveal melanoma cell line MUM-2B compared with that in the MUM-2C with low invasiveness. Of 82 primary uveal melanoma tissues, 35 exhibited high expression of legumain, while the other 47 specimens exhibited low or negative expression of legumain. High legumain expression was primarily associated with local invasion of UM. Overall survival analysis revealed that the patients with high legumain expression exhibited poorer survival than patients with low/negative legumain expression. These findings suggested that upregulation of legumain is associated with malignant behavior of UM and that legumain may be used as an negative prognostic factor as well as a therapeutic target.

Uveal Melanoma Patient-Derived Xenografts

The prognosis of uveal melanoma (UM) remains poor due to a high risk of metastatic disease. No effective therapies have been described for metastatic UM, and new therapies are needed to improve the outcome for these patients. To achieve this goal, new preclinical animal models are needed. Existing animal models, including genetically engineered mice and orthotopic xenograft models in immunodeficient animals, are inadequate for modelling human disease. In this review, we present the development and characterization of a large panel of UM patient-derived xenografts (PDXs). Based on molecular features as identified in patient tumors, i.e. histopathological classification, specific gene mutations, as well as genomic and gene expression profiles, we show that PDXs closely resemble many important genetic and histological aspects of human UM with a remarkable stability over the course of their in vivo maintenance. Our techniques for establishing and maintaining primary UMs as xenograft tumors in immunodeficient mice provide a high degree of genetic conservation between the primary tumor and its xenograft over multiple in vivo passages. These models therefore represent a significant advance in the resources available for drug screening and studies of the pathogenesis of UM.

Metabolic activity of primary uveal melanoma on PET/CT scan and its relationship with monosomy 3 and other prognostic factors

Purpose

To correlate the metabolic activity of primary uveal melanoma on positron emission tomography (PET)/CT scan with known clinical and pathological prognostic factors.

Methods

A retrospective cohort analysis of eyes enucleated for uveal melanoma that underwent preoperative imaging with a PET/CT scan was performed. Tumour dimensions were recorded and classified using Collaborative Ocular Melanoma Study (COMS) and American Joint Committee on Cancer (AJCC) Tumour - Nodes - Metastases (TNM) criteria. Metabolic activity was determined by measurement of the maximal standardised uptake value (SUVmax) on PET/CT scans. SUVmax of >2.5 and >4 was also used as cut-off value for metabolic positivity. Chromosome 3 and 8 status was determined using fluorescence in situ hybridisation analysis. Pearson correlation, χ² test and non-parametric tests were used. p<0.05 was considered statistically significant.

Results

Seventy-six uveal melanomas were imaged preoperatively with a PET/CT scan. Overall 92% of tumours had a SUVmax >2.5 and 67% had a SUVmax >4. Monosomy 3 was found in 35 melanomas, of which 94% had an SUVmax >2.5 and 80% had an SUVmax >4. Only 57% of disomy 3 melanomas had an SUVmax >4. SUVmax was significantly increased in tumours with monosomy 3 (p=0.043) but not in tumours with chromosome 8 gain (p=0.49). SUVmax and increasing tumour size were positively correlated (p<0.05). Using the AJCC criteria, there was a significant difference in SUVmax among prognostic groups (p=0.024). There was no correlation with histopathological cell type (p=0.923).

Conclusions

Metabolic activity of uveal melanoma on PET/CT scan is positively correlated with monosomy 3, increasing tumour size and TNM prognostic groups. No association with chromosome 8 gain or histopathology cell type was noted. SUVmax >4 is a relative but not an absolute indicator of monosomy 3 status.

Evidence of epidermal growth factor receptor expression in uveal melanoma: inhibition of epidermal growth factor-mediated signalling by Gefitinib and Cetuximab triggered antibody-dependent cellular cytotoxicity

Despite advances in surgery and radiotherapy of uveal melanoma (UM), many patients develop distant metastases that poorly respond to therapy. Improved therapies for the metastatic disease are therefore urgently needed. Expression of the epidermal growth factor receptor (EGFR), a target of kinase inhibitors and humanised antibodies in use for several cancers, had been reported. Forty-eight human UMs were analysed by expression profiling. Signalling was tested in three EGFR expressing UM cell lines by Western blotting using phosphorylation specific antibodies for EGFR and the downstream mediators AKT (v-akt murine thymoma viral oncogene homolog) and extracellular signal-regulated kinase (ERK). Evidence for signalling in tumours was obtained through the application of a UM-specific EGF-signature. The EGFR specific kinase inhibitor, Gefitinib and the humanised monoclonal antibody, Cetuximab, were tested for their effect on EGFR signalling. Natural killer cell mediated antibody-dependent cellular cytotoxicity (ADCC) and tumour necrosis factor α (TNF-α) release was analysed for Cetuximab. Fourteen of 48 UMs and three of 14 cell lines (over-)express EGFR, at least in part due to trisomy of the EGFR locus on chromosome 7p12. EGFR and the downstream mediator, AKT, are phosphorylated upon stimulation with EGF in EGFR expressing cell lines. EGFR over-expressing tumours but not EGFR negative tumours show an activated EGF-signature. Gefitinib inhibits EGFR and AKT phosphorylation and Cetuximab induces EGFR phosphorylation but inhibits signalling to AKT induced with EGF. Cetuximab triggers natural killer (NK) cells to lyse EGFR+ cell lines and to release TNF-α. EGFR appears suited as a novel molecular drug target for therapy of uveal melanoma.

Liver function testing is not helpful for early diagnosis of metastatic uveal melanoma

OBJECTIVE

To study the relevance of liver function test (LFT) results for early detection of liver metastasis of uveal melanoma.

DESIGN

Evaluation of diagnostic test.

PARTICIPANTS

Eighty-eight patients were included in whom metastasis developed while undergoing semiannual follow-up with LFTs, including aspartate-aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (γGT), lactate dehydrogenase (LDH), and phosphatase alkaline (PA). As controls, 174 patients with uveal melanoma without metastasis were included.

METHODS

The diagnostic attributes of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each test were estimated from cross-tabulation tables of test results according to the diagnosis of metastasis. The proportions of false-positive results between groups of patients with and without metastasis were compared in log-binomial regression models.

MAIN OUTCOME MEASURES

Sensitivity, specificity, PPV, NPV, and cost evaluation.

RESULTS

Metastases were detected after LFT abnormality (at least 1 abnormal test result) in 40 (45%) patients. The overall sensitivity of LFTs ranged from 12.5% to 58.0%, and the PPV ranged from 9.4% to 38.6%. The overall specificity and NPV were 90% or greater. The proportions of false-positive results between groups of patients with and without metastasis did not differ significantly (all P≥0.38). Using a cost evaluation, semi-annual screening by LFTs was calculated to cost $35.5/year per patient, including liver imaging induced by true and false-positive results.

CONCLUSIONS

Isolated or combined LFTs for AST, ALT, γGT, LDH, and PA are not helpful for detection of early metastasis. However, the high NPVs suggest that LFT screening can allow clinicians to reassure the patient when the LFT results are negative.

[Case report of a 45-year-old man with uveal melanoma and suspect controlateral choroidal nævus]

INTRODUCTION

Uveal melanoma is the most common adult primary intraoculary tumor. Bilateral tumor is very rare, but must not be underestimated because early diagnosis and care improve the survival and the visual prognosis.

OBSERVATION

We report the case of a patient treated for a left parapapillary choroidal melanoma by disk of ruthenium ((106)Ru), and a follow-up every 3 months for an atypical choroidal large-sized controlateral nævus levelling the macular area. This right nævus changed in 2009 leading to suspicion of a growing melanoma. Because the visual acuity of the left eye was limited to 20/2000, we wanted to confirm this growth before beginning a treatment. But for 3 years the tumor has remained stable and asymptomatic, with a disease staging still negative. To this day, no curative treatment has been started on the right eye.

DISCUSSION

In spite of clinical (To Find Small Ocular Melanomas (TFSOM) for example) and paraclinical arguments, it is sometimes difficult to differentiate a large nævus from an early melanoma. Evolution of the tumor often allows to confirm the diagnosis. However, the sole growth of a nævus is not specific of a choroidal melanoma. When confronted with suspicion of a small choroidal melanoma, some authors recommend an immediate treatment for the tumor; others prefer to confirm without a doubt a tumoral growth. It is necessary to weigh out the iatrogenic risks of a conservative treatment on the visual acuity in a monophtalm patient on one side, and the vital risk for the patient on the other side, which seems to be limited in case of small-sized melanoma with a slow evolution.

CONCLUSION

A bilateral choroidal melanoma is rare. Systematic and repeated examinations of both eyes are essential. Management of these complicated cases often leads to discussion.

Ex vivo enrichment of circulating anti-tumor T cells from both cutaneous and ocular melanoma patients: clinical implications for adoptive cell transfer therapy

Tumor-infiltrating lymphocytes (TILs) have been successfully used for adoptive cell transfer (ACT) immunotherapy; however, due to their scarce availability, this therapy is possible for a limited fraction of cutaneous melanoma patients. We assessed whether an effective protocol for ex vivo T-cell expansion from peripheral blood mononuclear cells (PBMCs), suitable for ACT of both cutaneous and ocular melanoma patients, could be identified. PBMCs from both cutaneous and ocular melanoma patients were stimulated in vitro with autologous, irradiated melanoma cells (mixed lymphocyte tumor cell culture; MLTCs) in the presence of IL-2 and IL-15 followed by the rapid expansion protocol (REP). The functional activity of these T lymphocytes was characterized and compared with that of TILs. In addition, the immune infiltration in vivo of ocular melanoma lesions was analyzed. An efficient in vitro MLTC expansion of melanoma reactive T cells was achieved from all PBMC’s samples obtained in 7 cutaneous and ocular metastatic melanoma patients. Large numbers of melanoma-specific T cells could be obtained when the REP protocol was applied to these MLTCs. Most MLTCs were enriched in non-terminally differentiated T_EM cells homogeneously expressing co-stimulatory molecules (e.g., NKG2D, CD28, CD134, CD137). A similar pattern of anti-tumor activity, in association with a more variable expression of co-stimulatory molecules, was detected on short-term in vitro cultured TILs isolated from the same patients. In these ocular melanoma patients, we observed an immune infiltrate with suppressive characteristics and a low rate of ex vivo growing TILs (28.5% of our cases). Our MLTC protocol overcomes this limitation, allowing the isolation of T lymphocytes with effector functions even in these patients. Thus, anti-tumor circulating PBMC-derived T cells could be efficiently isolated from melanoma patients by our novel ex vivo enrichment protocol. This protocol appears suitable for ACT studies of cutaneous and ocular melanoma patients.

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.

Combined treatment of uveal melanoma liver metastases

Uveal melanoma (UM) is the most prevalent intraocular malignant tumor in the Western world. The prognosis of survival in the presence of metastatic disease is 2-7 months, depending on the treatment applied.

This article presents a case of metastatic UM with successful complex treatment of liver metastases.

A 49-year old female, underwent removal of the right eyeball in 1996 due to a histologically confirmed uveal melanoma. After 11 years, CT revealed a mass in the left kidney and multiple metastases in the liver. After left nephrectomy, 6 chemotherapy courses with dacarbazine were performed. The increasing liver metastases were observed. Additional 4 intraarterial (i/a) chemotherapy courses were administered using cisplatin, doxorubicin, fluorouracil, and interferon alfa. After few courses increase in CTC Grade 4 liver transaminases was seen. A partial response was observed, and in December 2008 the patient underwent surgery removing all liver metastases by 7 wedge or atypical resections. All margins were tumor-free. 21 months after liver resections and 14 years since diagnosis, the patient is alive without evidence of disease.

Successful treatment of metastatic uveal melanoma was due to a timely application of a combination of several treatment methods and good prognostic factors of the patient.

[Genomic profiling by comparative genomic hybridization: analysis of ten enucleated uveal melanoma cases]

AIM

To detect major chromosomal aberrations from enucleated uveal melanoma and relate them to hepatic metastasis and survival.

PATIENTS AND METHODS

Ten uveal melanomas enucleated between 2005 and 2008 in the Lyon Croix-Rousse Hospital were retrospectively analyzed using a 19 000-clone comparative genomic hybridization microarray.

RESULTS

The most frequent imbalances were the loss of chromosome 3 (8/10), gain of the 8q arm (7/10) or the entire chromosome 8 (2/10), and gain of the 6p arm (2/10). Most metastatic tumors (6/7) and all cases of death (5/5) concerned melanoma with monosomy 3 and gain of the 8q arm.

DISCUSSION AND CONCLUSION

Genome-wide array comparative genomic hybridization is a reliable tool for identifying uveal melanoma genomic imbalances. Gains of the 8q arm with monosomy 3 are frequent and are strongly associated with poor outcome. Gains of the 6p arm are rare and have a better prognosis. There is a mutually exclusive relationship between monosomy 3 and chromosome 6 abnormalities in our study. These results confirm previously published reports.

Establishment and characterization of a panel of human uveal melanoma xenografts derived from primary and/or metastatic tumors

PURPOSE

Uveal melanoma is the most common primary intraocular malignant tumor in adults and is defined by a poor natural outcome, as 50% of patients die from metastases. The aim of this study was to develop and characterize a panel of human uveal melanoma xenografts transplanted into immunodeficient mice.

EXPERIMENTAL DESIGN

Ninety tumor specimens were grafted into severe combined immunodeficient mice, and 25 transplantable xenografts were then established (28%). Relationship between tumor graft and clinical, biological, and therapeutic features of the patients included were investigated. Characterization of 16 xenografts included histology, molecular analyses by immunohistochemistry, genetic alteration analysis (single-nucleotide polymorphism), and specific tumor antigen expression by quantitative reverse transcription-PCR. Pharmacologic characterization (chemosensitivity) was also done in four models using two drugs, temozolomide and fotemustine, currently used in the clinical management of uveal melanoma.

RESULTS

Take rate of human uveal melanoma was 28% (25 of 90). Tumor take was independent of size, histologic parameters, or chromosome 3 monosomy but was significantly higher in metastatic tumors. Interestingly, in vivo tumor growth was prognostic for a lower metastasis-free survival in patients with primary tumors. A high concordance between the patients' tumors and their corresponding xenografts was found for all parameters tested (histology, genetic profile, and tumor antigen expression). Finally, the four xenografts studied displayed different response profiles to chemotherapeutic agents.

CONCLUSIONS

Based on these results, this panel of 16 uveal melanoma xenografts represents a useful preclinical tool for both pharmacologic and biological assessments.

Surgical management of liver metastases from uveal melanoma: 16 years' experience at the Institut Curie

BACKGROUND

Uveal melanoma is characterised by a high prevalence of liver metastases and a poor prognosis.

AIM

To review the evolving surgical management of this challenging condition at a single institution over a 16-year period.

PATIENTS AND METHODS

Between January 1991 and June 2007, among 3873 patients with uveal melanoma, 798 patients had liver metastases. We undertook a detailed retrospective review of their clinical records and surgical procedures. The data was evaluated with both uni- and multivariate statistical analysis for predictive survival indicators.

RESULTS

255 patients underwent surgical resection. The median interval between ocular tumour diagnosis and liver surgery was 68 months (range 19-81). Liver surgery was either microscopically complete (R0; n = 76), microscopically incomplete (R1; n = 22) or macroscopically incomplete (R2; n = 157). The median overall postoperative survival was 14 months, but increased to 27 months when R0 resection was possible. With multivariate analysis, four variables were found to independently correlate with prolonged survival: an interval from primary tumour diagnosis to liver metastases >24 months, comprehensiveness of surgical resection (R0), number of metastases resected (< or = 4) and absence of miliary disease.

CONCLUSIONS

Surgical resection, when possible, is able to almost double the survival and appears at present the optimal way of improving the prognosis in metastatic uveal melanoma. Advances in medical treatments will be required to further improve survival.

Melanoma associated spongiform scleropathy: characterization, biochemical and immunohistochemical studies

SUMMARY

Melanoma associated spongiform scleropathy (MASS) is a non-inflammatory scleral change with a spongiotic morphology seen in association with uveal melanoma. MASS is seen as whitish spindle shaped areas within the sclera that is adjacent to and in contact with a choroidal or ciliary body melanoma. This change can be seen as small scattered lesions in the inner scleral layers or as extensive areas along the whole extent of contact between the tumour and the sclera and involves most of the scleral thickness. MASS changes of different grades of severity were seen in 38% of 363 melanoma eyes investigated. The presence of MASS showed a statistical correlation with age. A significant high incidence of MASS was found in old age groups. This might due to the fact that MASS needs a longer period of contact between the tumour and the sclera to develop. It is also possible that age-related changes of the extracellular matrix might alter its response to melanoma produced factors leading to the development of MASS. The development of MASS and its severity are influenced by the extent of contact between the tumour and the sclera. This is supported by the significant statistical relation between the largest basal diameter of the tumours and the severity of MASS. Statistical correlation was found between MASS and scleral and extrascleral tumour extension. More than 90% of 82 specimens that showed tumour extension were associated with MASS. A biochemical analysis of scleral samples taken from areas with severe MASS showed a significant reduction of the main amino acids of collagen type I, which is the main scleral collagen. The amounts of total scleral proteins were significantly reduced. This scleral protein reduction is associated with an increase in glycosaminoglycans. These findings indicate a collagen degradation process. Immunohistochemical studies were performed to investigate the expression of matrix metalloproteinases (MMPs). In situ hybridization showed a significantly more frequent and more intense expression of MMP-2 by scleral fibroblasts in areas with MASS compared with areas without MASS. This was also seen by immunohistochemical staining. Similar high frequency and intense expression of MMP-2 were seen in tumour infiltrating macrophages. The results of biochemical and immunohistochemical studies indicate a collagen degradation process. This degradation may be the result of the proteolytic enzyme MMP-2 expressed by scleral fibroblasts under the effect of tumour humeral factors and/or tumour infiltrating macrophages. This scleral degradation results in fragmentation of the scleral collagen fibrils. This along with the accumulation of water in the sclera, as a result of the increase in the production of glycosaminoglycans, results in increase of scleral thickness in MASS areas and forms the histopathological picture of MASS. The scleral degradation may facilitate tumour invasion and may explain the statistical relation between MASS and scleral tumour invasion. MASS was found in a few of the eyes that had received pre-enucleation radiation. The possible explanation is that radiation might cause destruction of scleral fibroblasts reducing their ability to produce MMP-2, thus decreasing the development of MASS. No relation between MASS and survival was found. This is probably explained by the fact that the main cause of death due to uveal melanoma is distant metastasis. MASS changes are found to be associated with local tumour invasion but not statistically correlated to survival.

Targeted therapy for uveal melanoma

Uveal melanoma is the most common primary intra-ocular malignancy in adults. Overall mortality rate remains high because of the development of metastatic disease, which is highly resistant to systemic therapy. Improved understanding of the molecular pathogenesis of cancers has led to a new generation of therapeutic agents that interfere with a specific pathway critical in tumor development or progression. Although no specific genes have been linked to the pathogenesis of uveal melanoma, which differs from that of cutaneous melanoma, progress has been made in identifying potential targets involved in uveal melanoma apoptosis, proliferation, invasion, metastasis, and angiogenesis. This review focuses on the prospects for improving the systemic therapy of uveal melanoma using molecularly targeted agents that are currently in clinical use as well as agents being tested in clinical trials. Preclinical studies suggest potential benefit of inhibitors of Bcl-2, ubiquitin-proteasome, histone deactylase, mitogen-activated protein kinase and phosphatidylinositol-3-kinase-AKT pathways, and receptor tyrosine kinases. Modifiers of adhesion molecules, matrix metalloproteinase, and angiogenic factors also have demonstrated potential benefit. Clinical trials of some of these approaches have been initiated in patients with metastatic uveal melanoma as well as in the adjuvant setting after primary therapy.

[Natural development over 4 years of a macular small choroidal melanoma in a single-eyed patient]

We report the case of a single-eyed patient with a small (2.2 mm thick with largest tumor diameter 7.6 mm) choroidal melanoma involving the entire macular surface with few functional signs. Visual acuity was 20/63. The patient was informed of the side effects and so was followed regularly at the oncology unit over 4 years. During this period, the tumor volume increased fourfold (the thickness reached 4.3 mm and the LTD 10.4 mm), with visual acuity decreasing to 20/250: proton beam therapy was therefore performed. The patient showed no metastasis more than 2 years after the treatment. This unusual case raises the question of small choroidal melanoma management, especially if the patient is single-eyed, in good general health, middle-aged and if the tumor is retrofoveal with just a few functional signs: when, why and who should be treated?

Mélanome annulaire révélé par un hyphéma spontané

INTRODUCTION

Ring melanoma is a rare form of uveal melanoma characterized by the circumferential involvement of the ciliary body. Unilateral chronic and refractory glaucoma is a classic circumstance of diagnosis.

OBSERVATION

We report a case of ring melanoma revealed by acute intraocular hypertonia secondary to spontaneous hyphema. Iris and iridocorneal angle were diffusely invaded by the tumor. The fundus was masked but B-scan ultrasonography revealed a voluminous ciliochoroidal tumor. The patient had been enucleated. Pathological examination confirmed the diagnosis of ring melanoma. The tumor involved angle structures. The patient died 1 year later because of metastasis.

DISCUSSION

Acute or chronic ocular hypertonia is a classic but rare circumstance of uveal melanoma diagnosis. Many mechanisms exist: neovascular glaucoma, secondary angle closure, involvement of angle structures, and trabecular obstruction by tumor cells or pigment. Acute intraocular hypertonia secondary to hyphema is more exceptional. Our observation highlights that apart from the classic situation of acute angle closure glaucoma, intraocular hypertonia requires meticulous fundus examination, if necessary using B-scan ultrasonography.