Comparison of Tumor-Associated Vasculatures in Uveal and Cutaneous Melanomas

Tumour Angiogenesis in Uveal Melanoma Is Related to Genetic Evolution

Increased angiogenesis is associated with a higher metastasis- and mortality rate in uveal melanoma (UM). Recently, it was demonstrated that genetic events, such as 8q-gain and BAP1-loss, influence the level of immune infiltrate. We aimed to determine whether genetic events, and specific cytokines, relate to angiogenesis in UM. Data from UM patients who underwent enucleation between 1999 and 2008 were analysed. Microvascular density (MVD) and the presence of infiltrating immune cells were determined with immunohistochemistry (IHC) and immunofluorescence in 43 cases. Chromosome status, BAP1 IHC and mRNA expression of angiogenesis-related genes were known in 54 cases. Tumours with monosomy 3/BAP1-loss showed a higher MVD compared to tumours with disomy 3/normal BAP1 expression (p = 0.008 and p = 0.004, respectively). Within BAP1-positive lesions (n = 20), 8q-gain did not relate to MVD (p = 0.51). A high MVD was associated with an increased expression of angiopoietin 2 (ANGPT2) (p = 0.041), Von Willebrand Factor (VWF) (p = 0.010), a decreased expression of vascular endothelial growth factor B (VEGF-B) (p = 0.024), and increased numbers of tumour-infiltrating macrophages (CD68+, p = 0.017; CD68+CD163+, p = 0.031) and lymphocytes (CD4+, p = 0.027). Concluding, vascular density of UM relates to its genetic profile: Monosomy 3 and BAP1-loss are associated with an increased MVD, while an early event (gain of 8q) is not independently related to MVD, but may initiate a preparation phase towards development of vessels. Interestingly, VEGF-B expression is decreased in UM with a high MVD.

Intraocular activation of angiogenic and inflammatory pathways in uveal melanoma

PURPOSE

To identify and quantify angiogenic and inflammatory cytokines in aqueous and vitreous humor in eyes with untreated uveal melanoma and to analyze clinicopathologic correlations.

METHODS

Intraocular fluid samples of patients (uveal melanoma aqueous n = 21, vitreous n = 34) and controls (cataract aqueous n = 41, vitreomacular traction aqueous n = 35, vitreous n = 36) were taken intraoperatively and analyzed using Luminex xMAP suspension array technology. Beadlyte kits were used for detection of 28 different cytokines.

RESULTS

Flt-3 ligand, interleukin (IL) 1α, IL-6, IL-8, interferon-γ inducible protein (IP)-10, monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1α, platelet-derived growth factor AA, and vascular endothelial growth factor were significantly elevated in aqueous and vitreous of melanoma eyes when compared with controls. Eotaxin was significantly elevated in aqueous, and IL-7 and RANTES were significantly elevated in vitreous samples of melanoma eyes. Interferon-γ inducible protein 10, macrophage inflammatory protein 1α (aqueous and vitreous), Flt-3 ligand, IL-6, IL-8, and MCP-1 (vitreous) correlated with tumor dimensions. Further correlations were found between infiltration of Bruch membrane and Flt-3 ligand, MCP-1 (aqueous and vitreous), IL-8, interferon-γ inducible protein 10, macrophage inflammatory protein 1α, and platelet-derived growth factor AA (vitreous). Analyzing 16 paired aqueous and vitreous melanoma samples, Flt-3 ligand, IL-7, interferon-γ inducible protein 10, MCP-1, and platelet-derived growth factor AA were significantly elevated in vitreous, and IL-1α and vascular endothelial growth factor in aqueous samples.

CONCLUSION

A range of significantly elevated angiogenic, inflammatory, and chemotactic cytokines in eyes with uveal melanoma supports the link between inflammation and tumorigenesis.

Ocular melanoma: what's new?

PURPOSE OF REVIEW

The purpose of this review was to summarize available data on uveal melanoma biology and treatment in order to provide the medical community with a basic reference that would help to make further progress in this rare disease, which remains difficult to treat.

RECENT FINDINGS

The most relevant recent findings driving current clinical developments are in the elucidation of uveal melanoma genetics and genomics. The key driving mutations - that differ completely from cutaneous melanoma - have been identified. Based on the novel insights into key signaling pathways, the first clinical trials with targeted treatments have been implemented. However, systemic and regional chemotherapy approaches as well as other regional treatment modalities for liver metastases are also a major part of the current treatment armamentarium and are prospectively being evaluated.

SUMMARY

In summary, the recent biological findings and the creation of a series of clinical trials underscore how the international community is able to perform relevant advances in an extremely rare disease.

Genotypic profiling of 452 choroidal melanomas with multiplex ligation-dependent probe amplification

PURPOSE

Metastasis from uveal melanoma occurs almost exclusively with tumors showing chromosome 3 loss. We used multiplex ligation-dependent probe amplification (MLPA) to detect chromosome 1p, 3, 6p, 6q, 8p, and 8q abnormalities in uveal melanomas. The purpose of this study was to correlate our MLPA results with other risk factors and metastatic death.

EXPERIMENTAL DESIGN

Patients were included if they had a uveal melanoma involving choroid. Correlations between baseline risk factors were analyzed using the chi-square test (without Yates's adjustment) and the Mann-Whitney test, with log-rank analysis for associations with metastatic death.

RESULTS

The patients (194 female; 258 male) had a median age of 59.4 years and a median follow-up of 1.89 years. MLPA abnormalities occurred in a wide variety of combinations. Ten-year disease-specific mortality was 0% in 133 tumors with no chromosome 3 loss, 55% in tumors with chromosome 3 loss but no chromosome 8q gain, and 71% in 168 tumors showing combined chromosome 3 loss and 8q gain. In tumors with both these abnormalities, epithelioid melanoma cytomorphology, closed loops, and high mitotic rate correlated with poor survival as did lack of chromosome 6p gain.

CONCLUSIONS

These results support the use of MLPA for routine clinical prognostication, especially if the genetic data are considered together with clinical and histologic risk factors. We showed a wide variety of MLPA results, which suggests that chromosomal abnormalities in uveal melanoma accumulate in a variable sequence.