The prognostic significance of lymphocytic infiltration in malignant melanoma of the choroid

Enucleated globes with choroidal melanoma: A retrospective histopathological study and correlation with cytogenetic profile in 2 eye centers

Background

Uveal melanoma is the commonest intraocular malignant tumor in adults and the choroid is the commonest involved location. It is more prevalent in Caucasians; however, the demographics are widely variable based on ethnicity. Histopathological features have been correlated to the cytogenetic profile, which we intend to report through the study of enucleated eyes with choroidal melanoma (CM).

Materials and Methods

A retrospective review of 28 enucleated globes with CM in 2 tertiary eye centers (January 2000-December 2017). The tumors were histopathologically classified based on the 8th edition of the American Joint Committee on Cancer (AJCC). The histopathological risk factors and the AJCC classifications were correlated with Fluorescence in situ hybridization (FISH) for chromosomes 3 and 8 available results in 18/28 eyes.

Results

We have included 28 patients with a mean age of 56 years, 13 males (46.4%) and 15 females (53.6%). None had lymph node involvement or metastatic disease. The tumor size was categorized as 3 and 4 in 68% of eyes. Half tumors were of spindle cell type and were associated with absent cytogenetic abnormality in chromosomes 3 and 8 (P=0.005). Closed vascular loops presence was significantly associated with abnormal chromosomes 3 and 8 (P=0.027).

Conclusion

Patients in our area presented late with larger tumor size. The spindle cell CM was the commonest and correlated with negative FISH results, while the presence of closed vascular loops was a risk factor for abnormal FISH results hence expected worse prognosis. AJCC classification did not correlate well with our FISH results.

Uveal Melanoma, Angiogenesis and Immunotherapy, Is There Any Hope?

Uveal melanoma is considered a rare disease but it is the most common intraocular malignancy in adults. Local treatments are effective, but the systemic recurrence rate is unacceptably high. Moreover, once metastasis have developed the prognosis is poor, with a 5-year survival rate of less than 5%, and systemic therapies, including immunotherapy, have rendered poor results. The tumour biology is complex, but angiogenesis is a highly important pathway in these tumours. Vasculogenic mimicry, the ability of melanomas to generate vascular channels independently of endothelial cells, could play an important role, but no effective therapy targeting this process has been developed so far. Angiogenesis modulates the tumour microenvironment of melanomas, and a close interplay is established between them. Therefore, combining immune strategies with drugs targeting angiogenesis offers a new therapeutic paradigm. In preclinical studies, these approaches effectively target these tumours, and a phase I clinical study has shown encouraging results in cutaneous melanomas. In this review, we will discuss the importance of angiogenesis in uveal melanoma, with a special focus on vasculogenic mimicry, and describe the interplay between angiogenesis and the tumour microenvironment. In addition, we will suggest future therapeutic approaches based on these observations and mention ways in which to potentially enhance current treatments.

Aqueous immune mediators in malignant uveal melanomas in comparison to benign pigmented intraocular tumors

Background

To examine the usefulness of measuring immune mediators in aqueous humor samples for differentiating malignant uveal melanoma from benign pigmented intraocular tumors.

Methods

Thirteen eyes of 13 patients with uveal melanoma were studied, and 13 eyes of 13 patients with benign pigmented intraocular tumors served as controls. Undiluted samples of aqueous humor were collected, and a cytometric bead array was used to determine the aqueous humor concentrations of 35 immune mediators comprising 14 interleukins (IL), interferon-γ, interferon-γ-inducible protein-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, MIP-1β, regulated on activation normal T cell expressed and secreted, monokine induced by interferon-γ, basic fibroblast growth factor, Fas ligand, granzyme A, granzyme B, eotaxin, interferon-inducible T-cell alpha chemoattractant, fractalkine, granulocyte macrophage colony-stimulating factor, granulocyte colony-stimulating factor, vascular endothelial growth factor, angiogenin, tumor necrosis factor-α, lymphotoxin-α, and CD40L.

Results

Aqueous humor levels of angiogenin, IL-8, and MCP-1 were significantly higher in eyes with malignant melanoma than in those with benign tumors (p < 0.05).

Conclusions

Angiogenin, IL-8, and MCP-1 levels in aqueous humor may be potential markers for distinguishing malignant uveal melanoma from benign pigmented intraocular tumors, and may be a useful adjunct to histomorphology, diagnostic imaging, and other biomarkers for the diagnosis and appropriate clinical management of malignant uveal melanoma.

Electronic supplementary material

The online version of this article (doi:10.1007/s00417-016-3541-5) contains supplementary material, which is available to authorized users.

Increased numbers of tumor-lysing monocytes in cancer patients

Lymphatic infiltration is a well known phenomenon in different tumors including endocrine malignancies. However, little is known about the role of antigen-presenting cells and T cell activation in this context. The aim of our study was to investigate the quantity and function of CD14+/CD56+ monocytes in tumor patients including endocrine malignancies. First, these cells were characterized in peripheral blood of endocrine and non-endocrine cancer patients as well as in tumor tissue samples. Cancer patients had in mean 3.7 times more CD14+/CD56+ monocytes in the peripheral blood compared to healthy controls (p≤0.0001), while the highest frequencies were seen in patients with heavy tumor load. Importantly, these cells additionally expressed several NK cell markers. A proof of CD14+/CD56+ infiltrations into papillary thyroid carcinoma was shown by immunohistochemical analyses. Functional analyses revealed an apoptosis inducing capacity in vitro after IFN-α re-stimulation. Our data indicate the importance of tumor-lysing monocytes in antitumor immunity.

Expression of vascular endothelial growth factor-A, matrix metalloproteinase-9, and extravascular matrix patterns and their correlations with clinicopathologic parameters in posterior uveal melanomas

PURPOSE

To assess extravascular matrix patterns (EMP) and expression of vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) in posterior uveal melanomas and their correlations with histopathologic parameters and metastasis.

METHODS

This study was conducted on 100 consecutive eyes enucleated for posterior uveal melanomas. All tumors were examined by immunohistochemical techniques for VEGF-A and MMP-9 expression, and the presence of EMPs was assessed on routine paraffin sections stained with reticulin. Cell type, tumor localization, degree of pigmentation, necrosis, mitotic index, lymphocytic infiltration, and scleral and optic nerve invasion were analyzed by using light microscopy. No eyes had received prior treatment such as radiotherapy or transpupillary thermotherapy.

RESULTS

Identified histopathologically, cell types were spindle cells in 60% of the cases, mixed cells in 14%, and epithelioid cells in 26% of tumors. Positive reaction for VEGF-A and MMP-9 was present in 84% and 72% of the tumors, respectively. Microvascular loops and/or networks were seen in 34% of the tumors, with the remaining 16% of the tumors displaying an arc pattern, 21% displaying a parallel pattern, and 29% displaying the normal pattern. The relationships between VEGF-A and MMP-9 expression and necrosis, the degree of lymphocyte infiltration, mitotic rate, and the formation of loop and network patterns were found to be statistically significant (P < 0.05). Metastatic disease developed in 14 patients during follow up.

CONCLUSIONS

The incidence of metastatic melanoma increased with the increasing expression of VEGF-A and MMP-9. Our data suggest that increasing VEGF-A and MMP-9 expression and the EMP can be used as independent prognostic factors in the management of posterior uveal melanoma following enucleation.

High frequency of allele-specific down-regulation of HLA class I expression in uveal melanoma cell lines

Uveal melanoma is the most common primary intra-ocular tumor in adults and has a high mortality rate due to liver metastases, for which no effective treatment is available. To investigate whether immunotherapy might be feasible in uveal melanoma, the HLA class I surface expression of 6 uveal melanoma cell lines was analyzed by flow cytometry using a broad panel of allele-specific monoclonal antibodies. To up-regulate HLA expression, cells were also cultured with IFN-alpha or -gamma. In general, expression of HLA-A alleles was high (except for cell line EOM-3) and could be further up-regulated by both IFN-alpha and -gamma. In cell line EOM-3, IFN-gamma treatment resulted in significant HLA-A expression while IFN-alpha treatment did not. Expression of HLA-B alleles was low or even negative. Variable effects were observed after IFN treatment. In 3 cell lines, expression of some HLA-B alleles could not be induced by IFN-alpha or -gamma: HLA-B44 in cell line 92-1, HLA-B15 in cell line OCM-1 and HLA-B5 in cell line MEL-202. The other B alleles of these cell lines showed enhanced expression levels upon IFN stimulation. In OMM-1 cells, IFN-alpha and -gamma increased the expression of HLA-A but did not induce expression of the 2 B alleles, indicating an HLA-B locus-specific loss. We thus found a high frequency of allele-specific and locus-specific down-regulation of HLA expression in uveal melanoma cell lines. Some of these defects were not restored by IFN-alpha or -gamma treatment. The lack of HLA expression may explain why uveal melanoma cells escape immune surveillance by cytotoxic T cells and complicate the development of immunotherapy in uveal melanoma.

Immunoregulation of intraocular tumours

Intraocular tumours reside within an organ that provides sanctuary from many immunological defence mechanisms. Antigens displayed on many intraocular tumours can elicit an aberrant systemic immune response in which systemic antigen-specific delayed-type hypersensitivity (DTH) is actively downregulated, thus denying the host one potential effector mechanism for controlling its intraocular tumour. Constituents within the aqueous humour inhibit the expression of DTH and natural killer cell effector mechanisms within the eye and thus protect intraocular tumours from immune-mediated rejection. Some experimental intraocular tumours in mice express potent tumour-specific antigens that stimulate the expansion of tumour-specific robust cytotoxic T lymphocyte (CTL) populations which enter the eye and mediate tumour rejection by piecemeal tumour necrosis. However, the presence of tumour-infiltrating lymphocytes (TIL) within an intraocular tumour does not inevitably lead to tumour resolution. In some cases CTL precursors infiltrate the intraocular tumour but fail to differentiate into mature cytolytic effector cells. Although uveal melanomas express melanoma-specific and melanoma-associated antigens that are capable of eliciting both humoral and cellular immunity, formidable barriers prevent the expression of tumour immunity. These barriers include: (a) anterior chamber-associated immune deviation; (b) in situ suppression of DTH effector cells; (c) suppression of natural killer cell activity in oculi; and (d) inactivation of the complement cascade by regulatory proteins expressed on uveal melanoma cells.

HLA expression and tumor-infiltrating immune cells in uveal melanoma

BACKGROUND

In uveal melanoma, both the amount of tumor-infiltrating cells and the level of expression of HLA antigens are quite variable. We hypothesized that low levels of HLA expression lead to a lack of antigen presentation, which might prevent proper immunologic recognition of the tumor. This lack of recognition might subsequently lead to low levels of tumor-infiltrating cells.

METHODS

To test this hypothesis, we determined the type and number of tumor-infiltrating cells in tumor sections from 24 uveal melanomas. We applied monoclonal antibodies directed against different types of immune cells and compared the results with the expression of HLA class I and class II antigens on the tumor cells.

RESULTS

Infiltrating immune cells were observed in all uveal melanomas (although in small amounts), with a predominance of T lymphocytes. Significant positive correlations were observed between the number of CD3+ cells (T lymphocytes) and monomorphic HLA class I expression, allele-specific HLA-A2 and Bw4 expression, and HLA class II expression. Furthermore, the number of CD4+ cells (T helper cells, monocytes/ macrophages) and of CD11b+ cells (monocytes/macrophages) was significantly correlated with the level of monomorphic HLA class I expression.

CONCLUSION

These data support our hypothesis that low levels of HLA expression (and therefore a lack of presentation of tumor-specific antigens) may lead to a low level of tumor infiltrate.

Quantitative assessment of the blood-aqueous barrier in human eyes with malignant or benign uveal tumors

We assessed alterations of the blood-aqueous barrier in 43 eyes with malignant melanoma (31 choroidal and 12 ciliary body), 40 eyes with benign uveal tumors, and 199-age matched normal control eyes. Aqueous flare was quantified with the laser flare-cell meter and correlated with clinical and histopathologic findings. Aqueous flare (photon counts/ms) was significantly higher in melanoma eyes (20.91 +/- 12.40) than in eyes with benign tumors (4.26 +/- 1.55) (P < .0001) and normal control eyes (3.99 +/- 1.14) (P < .0001). In melanoma eyes, clinical and histologic findings associated with significantly increased aqueous flare values were as follows: tumor height, serous retinal detachment, tumor necrosis, lymphocytic tumor infiltration, and tumor hemorrhage. Development and growth of uveal melanomas are accompanied by marked alterations of the blood-aqueous barrier. The noninvasive laser flare-cell meter may give useful additional information about malignant and benign uveal tumors.

Necrosis and lymphocytic infiltration in choroidal melanomas

Patient survival, tumor lymphocytic infiltration and tumor necrosis were studied and evaluated in 43 enucleated eyes with the same histological diagnosis of spindle 'B' malignant melanoma of the choroid. A significant difference (P less than 0.05) was found between the survival rate of melanoma patients with no evidence of lymphocytic infiltration and/or necrosis in the tumor, compared to those with any evidence of of lymphocytic infiltration and/or tumor necrosis.

Estimation of DNA content in uveal melanomas by flow cytometry

Flow cytometry was used to evaluate ploidy and tumour cycle kinetics in fresh tissue samples obtained from 19 uveal melanomas. The results were compared with other parameters including, histological cell type, tumour size and anatomical location. Three tumours (15.8%) were aneuploid (two mixed cell, one epithelioid cell). Cell turnover was estimated in the 16 diploid tumours by summating the total percentage of cells in S and G2/M phases. We found the mean percentage of cells in G2/M/S to be 5.96% (range 2.2-9.8%). Spindle cell neoplasms appeared to have lower cell turnover rates (4.5 +/- 1.2%) than epithelioid cell turnover (8.4 +/- 1.2%). There was no correlation between cell turnover and either tumour size or anatomical location.

DNA cell cycle studies in uveal melanoma

We histologically studied uveal melanomas treated with surgery only (enucleation or ciliochoroidectomy), low-dose (20 Gy) preenucleation radiation followed by enucleation, or enucleated melanomas after high-dose (50 to 80 Gy) charged-particle beam therapy. There was significantly less bromodeoxyuridine uptake in irradiated vs nonradiated melanomas (P less than .0001). Similarly, tissue culture growth of irradiated tumors was significantly less (P less than .007). These data demonstrate destruction of reproductive integrity of helium ion-irradiated melanomas. The incorporation of bromodeoxyuridine and fine needle aspiration biopsy techniques may be useful in the delineation of successfully irradiated tumors from tumors with apparent growth secondary to radiation vasculopathy.

Malignant melanoma. Inflammatory mononuclear cell infiltrates in cerebral metastases during concurrent therapy with viral oncolysate

Five patients with advanced malignant melanoma, treated with viral oncolysate, had solitary central nervous system metastases that were removed surgically. Histologic examination revealed striking and significant mononuclear inflammatory cell infiltrates, consisting of a mean of 60% plasma cells and a lesser proportion of lymphocytes at the edges of the lesions, within their supporting fibrovascular trabeculae, and among the tumor cells. Comparable inflammatory changes were not found in solitary metastatic malignant melanomas removed surgically from the brains of 19 patients not treated with viral oncolysate. Similarly, multiple metastatic malignant melanomas obtained postmortem from the brains of 12 patients not treated with viral oncolysate showed minimal inflammatory responses. Ultrastructural examination of material from a single treated patient revealed morphologic abnormalities of the blood-brain barrier, changes that were perhaps conducive to infiltration of the neoplasm by inflammatory cells. The authors suggest that administration of viral oncolysate enhances the inflammatory cell response to metastatic malignant melanoma in the brain.

B- and T-lymphocytes in ocular disease

Ocular inflammatory diseases and ocular adnexal lymphoid tumors have become less obscure and intimidating by virtue of our ability to study the infiltrates in these various diseases for their B-lymphocyte and T-lymphocyte composition. Comparisons are also possible between lymphocytic profiles in the peripheral blood and the precise composition of the in situ infiltrates within the ocular tissue themselves. The availability of monoclonal antibodies, which can determine T-lymphocytic subsets such as T-helper cells and T-suppressor/cytotoxic cells, natural killer cells, and monocytes-histiocytes, has provided a powerful technology for the delineation of the distinctive immune composition of the inflammatory infiltrates, as well as any possible disturbances in T-cell immunoregulation. B-lymphocytes produce immunoglobulins, which may be misdirected as autoantibodies in local or systemic autoimmune diseases. Immunoglobulin-mediated and therefore B-cell derived conditions include vasculitis, progressive cicatricial ocular pemphigoid, Mooren's corneal ulcer, scleritis, and hay fever and vernal conjunctivitis. Other diseases in which B-lymphocytes, their immunoglobulin products or immune complexes formed with presently unknown antigens are potentially at fault are chronic non-specific uveitis; iridocyclitis in Behcet's syndrome; Fuch's heterochromic syndrome, ankylosing spondylitis, and Reiter's syndrome; Graves' disease; and idiopathic inflammatory orbital pseudotumor and myositis. T-cells do not produce immunoglobins, but rather secrete lymphokines or interact directly with receptors or determinants on viruses or target tissues (eg. immunosurveillance against neoplasia); it is possible that some autoimmune diseases are the result of neo-antigens on the surfaces of host tissues that have been coded for by a cryptic inciting virus. T-cell diseases include phlyctenulosis graft rejections, graft versus host disease, and possibly sympathetic ophthalmia and temporal arteritis. Natural killer cells are involved in many of the same diseases as cytotoxic T-cells, except that the former require no period of sensitization (natural immunity), whereas cytotoxic T-cells must undergo an antigen-specific blast transformation (acquired immunity of the delayed hypersensitivity type). In many diseases in which B-cell derived auto-antibodies are at fault, there may be local tissue or systemic T-cell imbalances, with a reduction in T-suppressor cells and a relative augmentation in T-helper cells, thereby facilitating production of misdirected auto-antibodies.(ABSTRACT TRUNCATED AT 400 WORDS)

Susceptibility of human ocular melanoma cells to spontaneous and interferon-augmented natural cytotoxicity

Due to the current interest in natural killer (NK) cells as a host defence mechanism against neoplasia, we have investigated the susceptibility of short-term cultures of human ocular melanoma cells to spontaneous and interferon (IFN)-augmented natural cytotoxicity. Cultures of ocular melanoma cells were readily established and identified as bipolar and multipolar pigmented melanoma cells. In short-term cytotoxicity assays these cell lines demonstrated a weak susceptibility to spontaneous human PBL natural cytotoxicity, and increased killing was observed using IFN-augmented cytotoxic effector cells. These findings may be pertinent in relation to the role of NK cells in vivo.