Sunlight exposure and pathogenesis of uveal melanoma

A UV-related risk analysis in ophthalmic malignancies: Increased UV exposure may cause ocular malignancies

Purpose

To explore the role of ultraviolet radiation (UVR) in the occurrence and development of various ocular malignancies.

Methods

In this article, we retrieved ocular malignancy data from the Global Cancer Observatory (GCO) and performed correlation analysis with the global UV index and sunshine duration. We searched for associated studies using the following databases: Embase, Pubmed, Cochrane Library, and Google Scholar. We conducted the literature by searching the Mesh terms denoting an exposure of interest ("UV radiation", "ultraviolet rays", and "ocular malignancies", All studies included are published until December 30, 2023 without language restrictions.

Results

The mechanisms and epidemiological statistics of UVR on the onset and progression of eyelid malignancies are the most studied and clear. The role of UVR in conjunctival melanoma is similar to that in eyelid melanoma. The relationship between uveal melanoma and UVR is controversial, however, it may have at least a certain impact on its prognosis. UVR causes ocular surface squamous neoplasia by further activating HPV infection.

Conclusions

UVR is a decisive risk factor for ocular malignancies, but the incidence of ultraviolet-induced tumors is also affected by many other factors. A correct and comprehensive understanding of the mechanisms of UVR in the pathogenesis of ocular malignant tumors can provide patients with more effective and selective immune regulation strategies.

Successful application of chemosaturation with percutaneous hepatic perfusion in metastatic uveal melanoma patient progressing after systemic treatment options: a case report

Uveal melanoma (UM) is a rare subtype of melanoma, accounting for less than 5% of all melanoma cases. Metastatic UM differs notably from cutaneous melanoma, exhibiting variations in etiology, prognosis, driver mutations, metastatic patterns, and poor responses to immune checkpoint inhibitors (ICI). Beyond local treatment options, such as resection, radiation therapy, and enucleation, and systemic treatments, such as ICIs, the approval of tebentafusp, a bispecific gp100 peptide-HLA-directed CD3 T-cell engager, marks a breakthrough in treating HLA-A*02:01 metastatic UM. Despite the advancements in treatment options, the long-term survival rates remain inadequate. We report a patient with metastatic UM who previously received ICI and progressed on tebentafusp treatment but subsequently exhibited a remarkable response to local treatment targeting liver metastasis. Such observations highlight the significance of exploring sequential therapeutic strategies for advanced UM, offering potential avenues to enhance treatment efficacy and patient prognosis.

Incidence and Mortality of Uveal Melanoma in Hungary: A Nationwide Study

Uveal melanoma (UM) is the most common primary malignant ocular tumour in adults, although its epidemiology in Central and Eastern Europe is unclear. This study aimed to analyse the incidence and all-cause mortality of UM in Hungary. This nationwide, retrospective, longitudinal study used data from the National Health Insurance Fund and included patients aged ≥18 years who were newly diagnosed with UM (ICD-10 C69.3 or C69.4) between 1 January 2012 and 31 December 2021. Age-standardised incidence and all-cause mortality rates were calculated using European Standard Population data from 2013. We identified 88 and 70 new patients with UM in 2012 and 2021, respectively, showing an almost stable trend. Age-standardised incidence rates varied between 6.40 and 10.96/1,000,000 person-years (PYs) during the analysed period. The highest age-standardised incidence was detected among men (13.38/1,000,000 PYs) in 2015. All-cause mortality decreased from 4.72/1,000,000 PYs to 0.79/1,000,000 PYs between 2012 and 2021. In conclusion, the UM incidence rate in Hungary is comparable to European incidence rates. The incidence did not markedly change, whereas all-cause mortality decreased during the study period, but this decline could not be attributed to improved treatment modalities for primary tumours and metastatic UM.

Introduction to Nutrition and Cancer

By the beginning of the year 2021, the estimated number of new cancer cases worldwide was about 19.3 million and there were 10.0 million cancer-related deaths. Cancer is one of the deadliest diseases worldwide that can be attributed to genetic and environmental factors, including nutrition. The good nutrition concept focuses on the dietary requirements to sustain life. There is a substantial amount of evidence suggesting that a healthy diet can modulate cancer risk, particularly the risk of colorectal and breast cancers. Many studies have evaluated the correlation between our diet and the risk of cancer development, prevention, and treatment. The effect of diet on cancer development is likely to happen through intertwining mechanisms including inflammation and immune responses. For instance, a greater intake of red and processed meat along with low consumption of fruits and vegetables has been associated with increased levels of inflammatory biomarkers that are implicated in cancer development. On the other hand, the consumption of phytosterols, vitamins, and minerals, which exert antioxidant and anti-inflammatory roles have been linked to lower cancer risk, or even its occurrence prevention. In this book, we aim to summarize the current knowledge on the role of nutrition in cancer to provide the best scientific advice in this regard.

Uveal melanoma in African Americans: Diagnostic challenges

Uveal melanoma (UM) is uncommon in African Americans. Owing to its rarity, UM may not be suspected in African Americans leading to delayed diagnosis. In addition, socioeconomic factors may also play a role in delayed diagnosis. Clinical and ultrasonographic features may be atypical due to racial pigmentation, necessitating diagnostic fine needle aspiration biopsy. Herein, we report an illustrative case series of 12 African Americans with UM highlighting clinical features and diagnostic challenges.

Clinical features and treatment outcomes of progressive uveal melanoma

Uveal melanoma (UM) is a rare malignant tumor that differs from cutaneous melanoma in terms of pathogenesis, clinical behavior, and treatment response. Despite treatment for the primary tumor, 50% of UM patients develop metastatic disease, with the liver being the most affected organ. Furthermore, UM responds poorly to chemotherapy and immune checkpoint inhibitors. We present a clinical case of a 58-year-old female patient who was diagnosed with right eye choroidal melanoma cT2aN0M0. For the treatment of the initial tumor, the patient received stereotactic radiotherapy. However, 11 months after the initial diagnosis, the disease had progressed to the liver. The patient underwent radiofrequency ablation of liver metastases, then as the UM progressed - anti-PD-1 immunotherapy with nivolumab and ipilimumab were prescribed for the first-line palliative systemic treatment, later chemotherapy with dacarbazine (5 cycles) as the second-line systemic treatment. Based on the Foundation-One®CDx findings and an overview of clinical trials data, the MEK inhibitor trametinib was prescribed as a third-line palliative treatment. The patient died due to cancerous intoxication, with overall survival (OS) of 28 months (∼2.33 years) and a progression-free survival (PFS) of 11 months (∼0.92 years) since the initial diagnosis. Treatment-related adverse events could have an impact on the general health condition of the patient.

Intrinsic Disorder in BAP1 and Its Association with Uveal Melanoma

Background: Specific subvariants of uveal melanoma (UM) are associated with increased rates of metastasis compared to other subvariants. BRCA1 (BReast CAncer gene 1)-associated protein-1 (BAP1) is encoded by a gene that has been linked to aggressive behavior in UM. Methods: We evaluated BAP1 for the presence of intrinsically disordered protein regions (IDPRs) and its protein−protein interactions (PPI). We evaluated specific sequence-based features of the BAP1 protein using a set of bioinformatic databases, predictors, and algorithms. Results: We show that BAP1’s structure contains extensive IDPRs as it is highly enriched in proline residues (the most disordered amino acid; p-value < 0.05), the average percent of predicted disordered residues (PPDR) was 57.34%, and contains 9 disorder-based binding sites (ie. molecular recognition features (MoRFs)). BAP1’s intrinsic disorder allows it to engage in a complex PPI network with at least 49 partners (p-value < 1.0 × 10−16). Conclusion: These findings show that BAP1 contains IDPRs and an intricate PPI network. Mutations in UM that are associated with the BAP1 gene may alter the function of the IDPRs embedded into its structure. These findings develop the understanding of UM and may provide a target for potential novel therapies to treat this aggressive neoplasm.

Characteristics, Treatments, and Survival of Uveal Melanoma: A Comparison between Chinese and American Cohorts

Simple Summary

This retrospective comparative cohort study aimed to determine whether there were racial or national differences in UM, by comparing the demographic and clinical characteristics, such as tumor size, onset age, trend and proportion of treatment modalities, and overall survival. In the two cohorts, we found that Chinese patients have a younger onset age and a better survival rate. The survival advantage was likely secondary to younger onset age. In addition, a greater proportion of Chinese patients received brachytherapy as opposed to enucleation compared with American patients. This study was the first time comparing patients from different countries and races, which may help ophthalmologists better understand the clinical characteristics of the disease and suggests the importance of early diagnosis and treatment.

Abstract

Uveal melanoma (UM) is the most common intraocular malignant carcinoma. This study aimed to compare the clinical features, treatment modalities, and prognosis of UM patients in China with those in America over a 15-year period. In the study, 4088 American patients with primary UM from the Surveillance, Epidemiology, and End Results (SEER) database and 1508 Chinese patients from Tongren-ophthalmology Research Association of Clinical Evaluation (TRACE) were included. Univariable and multivariable analyses were performed to determine prognostic factors and propensity score matching (PSM) and sensitivity analyses were applied to adjust for confounders and identify independent prognostic factors. Chinese patients were diagnosed at a younger age (mean ± SD, 47.3 ± 12.5 years vs. 59.7 ± 14.8 years) and tumors at diagnosis were larger (diameter: 12.0 ± 3.54 mm vs. 11.3 ± 8.27 mm; thickness: 7.13 ± 3.28 mm vs. 4.91 ± 3.01 mm). Chinese patients were more likely to undergo brachytherapy than American patients. Chinese patients had better overall survival than American patients while no significant differences exhibited after adjusting for age through PSM. In conclusion, compared with American patients, Chinese patients had younger onset age, larger tumors at diagnosis and better prognosis, mainly because of their younger age.

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.

Posterior uveal melanoma incidence and survival by AJCC tumour size in a 70-year nationwide cohort

PURPOSE

While early treatment of posterior uveal melanoma can save the eye, the effect of early treatment on survival remains unknown. Therefore, we aimed to determine whether the tumour size at diagnosis has changed over time, and if this has affected survival rates of patients with posterior uveal melanoma in Denmark.

METHODS

Nationwide retrospective cohort study linking data from registry-based resources to data from clinical charts and pathology records. Including all Danish patients diagnosed with posterior uveal melanoma from 1943 to 2017. Incidence rates were estimated as annual percentage change (APC) overall and by American Joint Committee on Cancer (AJCC) tumour sizes. The age-period-cohort model was applied to estimate the relative risk of calendar period. The cox proportional hazards model, relative survival Kaplan-Meier curves and cumulative incidence curves were applied to estimate the effect of calendar period on survival.

RESULTS

An overall increase in incidence rate of uveal melanoma was found (APC = 0.25%, 0.08-0.42; 95% CI). This was due to increasing incidence rate of AJCC T1 + T2 tumours (APC = 0.97%, 0.57-1.37; 95% CI), whereas no increase in incidence rates of AJCC T3 + T4 tumours was found (APC = -0.01%, -0.26 to 0.25; 95% CI). The disease-specific survival improved with calendar period for all tumour sizes (HR = 0.988; 0.984-0.993; 95% CI).

CONCLUSION

Increasing incidence rate and improved survival rate for uveal melanoma was found concordantly with a decrease in tumour size during a 70-year period.

The epidemiology of uveal melanoma in Germany: a nationwide report of incidence and survival between 2009 and 2015

Purpose

To calculate the overall incidence of uveal melanoma in Germany and to compare incidences in different German states. In addition, we computed the overall and cancer-specific survival rates nationwide.

Methods

Incidence data for the period between 2009 and 2015, covering the entire German population, was collected through the German Center for Cancer Registry. ICD-O-3 topography codes C69.3-C69.4 and histology codes for melanoma subtypes were used to collect the incidence data. Confidence Intervals with a level of 95% (95% CI) were calculated for rates. Survival was calculated using the Kaplan–Meier. The log-rank test was used for survival comparisons.

Results

This study comprised 3654 patients with uveal melanomas, including 467 (12.8%) with iridial and ciliary body tumors. The overall age-standardized incidence rate (ASIR) was 6.41 person per million. Generally, the ASIR was higher in males than females (6.67 (95% CI 6.37–6.98) vs. 6.16 (95% CI 5.88–6.45 per million). Higher crude incidence rates were noted in the northeastern states (12.5 per million (95% CI 10.5–14.7) in Mecklenburg-Vorpommern) compared with the southwestern states (2.1 per million (95% CI 1.7–2.6) in Hessen). The 5-year overall survival stood at 47%, while the cancer-specific survival stood at 84%. Multivariate analysis showed that women, younger patients, and patients living in Berlin achieved significantly higher overall survival.

Conclusion

Overall ASIR of uveal melanoma in Germany indicates that the disease is more common in males and that it follows the same geographical distribution previously noted in central European countries, with the highest incidence in northern parts of Germany.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00417-021-05317-7.

The Trends of Uveal Melanoma Research in the Past Two Decades and Future Perspectives

Evaluation of the research trends in uveal melanoma in the past two decades. Data were extracted from the Web of Science database website. VOSviewer and Citespace software were used to analyze the retrieved data. The leading country in terms of output and international collaboration is the USA. Research interest in genetic mutations, molecular pathways, and immunotherapy was remarkable in recent years. Most of the top ten journals are specialized in ophthalmology. In recent years, the hotspots include future perspectives, BAP1 mutation, therapeutic target, and systematic reviews. The keywords with the strongest citation bursts are immunotherapy, outcome, and in situ hybridization. The output of uveal melanoma research increased during the past two decades. Before 2015, the main focus of the research was to facilitate prognostication and metastatic risk stratification. Recently, research has moved to examine the metastatic microenvironment. Future research foci may include exploring the role of different mutations, immunotherapy, molecular alterations, and finding ideal clinical biomarkers.

The Impact of Ultraviolet Radiation on the Aetiology and Development of Uveal Melanoma

Uveal melanoma (UM) is currently classified by the World Health Organisation as a melanoma caused by risk factors other than cumulative solar damage. However, factors relating to ultraviolet radiation (UVR) susceptibility such as light-coloured skin and eyes, propensity to burn, and proximity to the equator, frequently correlate with higher risk of UM. These risk factors echo those of the far more common cutaneous melanoma (CM), which is widely accepted to be caused by excessive UVR exposure, suggesting a role of UVR in the development and progression of a proportion of UM. Indeed, this could mean that countries, such as Australia, with high UVR exposure and the highest incidences of CM would represent a similarly high incidence of UM if UVR exposure is truly involved. Most cases of UM lack the typical genetic mutations that are related to UVR damage, although recent evidence in a small minority of cases has shown otherwise. This review therefore reassesses statistical, environmental, anatomical, and physiological evidence for and against the role of UVR in the aetiology of UM.

Extracutaneous Melanoma

Extracutaneous melanomas (ECMs) represent a heterogeneous group of melanoma subtypes characterized by distinct clinical and biological features from cutaneous melanoma. These subtypes share an aggressive natural history with high mortalities compared with nonacral cutaneous melanoma (NACM). Although recent advances in NACM have made significant improvements in morbidity and mortality, ECMs continue to lag behind. As the pathogenesis and molecular features of these rare subtypes continue to emerge, therapeutic research has aimed to closing the gap.

Current molecular and clinical insights into uveal melanoma (Review)

Uveal melanoma (UM) represents the most prominent primary eye cancer in adults. With an incidence of approximately 5 cases per million individuals annually in the United States, UM could be considered a relatively rare cancer. The 90-95% of UM cases arise from the choroid. Diagnosis is based mainly on a clinical examination and ancillary tests, with ocular ultrasonography being of greatest value. Differential diagnosis can prove challenging in the case of indeterminate choroidal lesions and, sometimes, monitoring for documented growth may be the proper approach. Fine needle aspiration biopsy tends to be performed with a prognostic purpose, often in combination with radiotherapy. Gene expression profiling has allowed for the grading of UMs into two classes, which feature different metastatic risks. Patients with UM require a specialized multidisciplinary management. Primary tumor treatment can be either enucleation or globe preserving. Usually, enucleation is reserved for larger tumors, while radiotherapy is preferred for small/medium melanomas. The prognosis is unfavorable due to the high mortality rate and high tendency to metastasize. Following the development of metastatic disease, the mortality rate increases to 80% within one year, due to both the absence of an effective treatment and the aggressiveness of the condition. Novel molecular studies have allowed for a better understanding of the genetic and epigenetic mechanisms involved in UM biological activity, which differs compared to skin melanomas. The most commonly mutated genes are GNAQ, GNA11 and BAP1. Research in this field could help to identify effective diagnostic and prognostic biomarkers, as well as novel therapeutic targets.

Uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. UMs are usually initiated by a mutation in GNAQ or GNA11, unlike cutaneous melanomas, which usually harbour a BRAF or NRAS mutation. The annual incidence in Europe and the USA is ~6 per million population per year. Risk factors include fair skin, light-coloured eyes, congenital ocular melanocytosis, ocular melanocytoma and the BAP1-tumour predisposition syndrome. Ocular treatment aims at preserving the eye and useful vision and, if possible, preventing metastases. Enucleation has largely been superseded by various forms of radiotherapy, phototherapy and local tumour resection, often administered in combination. Ocular outcomes are best with small tumours not extending close to the optic disc and/or fovea. Almost 50% of patients develop metastatic disease, which usually involves the liver, and is usually fatal within 1 year. Although UM metastases are less responsive than cutaneous melanoma to chemotherapy or immune checkpoint inhibitors, encouraging results have been reported with partial hepatectomy for solitary metastases, with percutaneous hepatic perfusion with melphalan or with tebentafusp. Better insight into tumour immunology and metabolism may lead to new treatments.

Mutation spectrum in GNAQ and GNA11 in Chinese uveal melanoma

Uveal melanoma is the most common intraocular cancer in the adult eye. R183 and Q209 were found to be mutational hotspots in exon 4 and exon 5 of GNAQ and GNA11 in Caucasians. However, only a few studies have reported somatic mutations in GNAQ or GNA11 in uveal melanoma in Chinese. We extracted somatic DNA from paraffin-embedded biopsies of 63 Chinese uveal melanoma samples and sequenced the entire coding regions of exons 4 and 5 in GNAQ and GNA11. The results showed that 33% of Chinese uveal melanoma samples carried Q209 mutations while none had R183 mutation in GNAQ or GNA11. In addition, seven novel missense somatic mutations in GNAQ (Y192C, F194L, P170S, D236N, L232F, V230A, and M227I) and four novel missense somatic mutations in GNA11 (R166C, I200T, S225F, and V206M) were found in our study. The high mutation frequency of Q209 and the novel missense mutations detected in this study suggest that GNAQ and GNA11 are common targets for somatic mutations in Chinese uveal melanoma.

Changes in Ultraviolet Radiation Exposure to the Ocular Region: A Population-Based Study

In contrast to the well-established association between ultraviolet radiation (UVR) exposure and skin cancers, the relationship between UVR and uveal malignant melanoma (UM) remains controversial. To address this controversy, we evaluated the incidence rates of cutaneous malignancies in the eyelids as a proxy for UVR exposure in the ocular region using a population-based cancer registry. Overall, 74,053 cases of eyelid basal cell carcinoma (BCC) and 7890 cases of melanoma over a 26-year period (1982–2007) were analyzed. The incidence of eyelid basal cell carcinoma and uveal melanoma remained stable, whereas other cutaneous areas demonstrated an increase in the rates. A comparability test demonstrated that BCC incidence trends were significantly different between the eyelid versus both chronically exposed (males p = 0.001; females p = 0.01) and intermittently exposed skin (males and females, p = 0.0002), as well as the skin of the face (males p = 0.002; females p = 0.02). Similarly, melanoma trends were significantly different between the UM group versus both chronically exposed cutaneous melanoma (CM) (males p = 0.001; females p = 0.04) and intermittently exposed CM (males p = 0.005), as well as facial skin CM (males and females p = 0.0002). The discrepancy of cancer incidence between tumors in the peri-ocular region versus the rest of the body suggests that the peri-ocular region might have a different or unique exposure pattern to ultraviolet radiation.

Clinical and histopathological features of choroidal melanoma-related enucleated eyes in a Spanish tertiary hospital

OBJECTIVE

To study clinical and pathological variables leading to a poor prognosis in a sample of uveal malignant melanoma patients who required eyeball enucleation as final treatment approach. All patients were seen and treated in the same public tertiary hospital in Madrid (Spain) within a 6-year time-period.

MATERIALS AND METHODS

Longitudinal observational retrospective study. The presence of clinical and pathologic factors known to be linked to poor prognosis, as well as other features, was assessed in 30 malignant melanoma: 20 de novo-enucleated malignant melanoma eyes (group A), and 10 in eyes that received radiotherapy prior to enucleation (group B). The diagnostic reliability of magnetic resonance imaging was assessed by comparing it with the histology results (gold standard) as a means to detect scleral and extra-scleral extension.

RESULTS

Tumour size, Bruch's membrane rupture, scleral infiltration, and distance to the optic nerve were the most decisive factors for a poor prognosis in the study sample. In 93% of cases the condition was under control, with a 6% incidence rate of metastatic spread and a 100% rate of overall survival for a mean follow-up period of 3±1.5 (range 1.2-6) years. In the study population, the sensitivity of the magnetic resonance imaging to detect scleral infiltration was 27%, which increased to 100% for identifying extra-scleral involvement.

CONCLUSIONS

The analyses of the clinical and pathological data collected within the framework of this study justify enucleation as the treatment of choice for the patients of this study. Magnetic resonance imaging was not found to be an optimum screening method to detect scleral infiltration in this study sample.

SDHD promoter mutations are rare events in cutaneous melanomas but SDHD protein expression is downregulated in advanced cutaneous melanoma

BACKGROUND

SDHD promoter mutations were reported in 4-10% of cutaneous melanomas. The advanced clinico-pathological and patient survival association with SDHD mutation and/or expression in cutaneous melanoma remains controversial.

OBJECTIVES

To evaluate the presence of SDHD promoter mutations and SDHD protein expression in a melanoma series and its possible association with prognosis and survival of the patients.

METHODS

We assessed SDHD promoter status in cutaneous melanomas (CM), ocular melanomas (OM) and melanoma cell lines, and the expression of SDHD protein by immunohistochemistry in CM and OM, and by western blot in melanoma cell lines. We explored the putative association between SDHD protein expression and clinico-pathological and prognostic parameters of melanoma.

RESULTS

We detected 2% of SDHD promoter mutations in CM, but none in OM and cell lines. SDHD protein expression was present in all CM, in OM and in all CM and OM derived cell lines analysed. A significant association between lower SDHD mean protein expression and presence of ulceration and higher pT stage was found.

CONCLUSIONS

SDHD promoter mutation seems to be a rare event in CM but SDHD lower expression might associate with worst prognostic features in CM.

Uveal schwannoma in a brown-eyed dog

An eleven-year-old, female spayed Boxer dog was diagnosed with a uveal schwannoma (formerly known as the spindle cell tumor of the blue-eyed dog or SCTBED) despite having a uniformly brown iris. The patient presented to emergency for ocular discomfort, and the right globe was subsequently enucleated due to glaucoma and submitted for histopathology. Upon histopathologic evaluation, a uveal schwannoma was diagnosed and confirmed with immunohistochemical staining. Complete metastatic evaluation 1 and 6 months after initial presentation did not reveal evidence of metastasis, and the dog remains systemically healthy. This case represents a unique variant of uveal schwannoma and is relevant because although the vast majority of these tumors occur in blue-eyed dogs, clinicians should not completely rule out this tumor as a differential based on the iris color.

Using risk factors for detection and prognostication of uveal melanoma

The early detection of malignancy, particularly uveal melanoma, is crucial in protecting visual acuity, salvaging the eye, and preventing metastasis. Risk factors for early detection of uveal melanoma have been clearly delineated in the literature and allow identification of melanoma when it is tiny and simulates a nevus. These factors include thickness >2 mm, presence of subretinal fluid (SRF), symptoms, the orange pigment, margin near optic disc, acoustic hollowness, surrounding halo, and absence of drusen. The importance of early detection is realized when one considers melanoma thickness, as each millimeter increase in melanoma thickness imparts 5% increased risk for metastatic disease. Newer imaging modalities like enhanced depth imaging optical coherence tomography and fundus autoflouroscence facilitate in detection of SRF and orange pigment. Additional molecular biomarkers and cytological features have been identified which can predict the clinical behavior of a small melanocytic lesion. Features that suggest a poor prognosis include higher blood levels of tyrosinase m-RNA, vascular endothelial growth factor, insulin-like growth factor; monosomy 3 and gains in chromosome 8. Management of uveal melanoma includes enucleation (for large), local eye wall resection, brachytherapy, charged particle irradiation, and thermotherapy (for small to medium tumors). Although the role of a good clinical evaluation cannot be underestimated, it is advisable to evaluate the various radiological, molecular, and cytological features, to enhance the accuracy of early diagnosis and improved prognosis.

Risk Factors and Relationship of Cutaneous and Uveal Melanocytic Lesions in Monozygotic and Dizygotic Twin Pairs

BACKGROUND

The similar genetic background of a pair of twins, and the similar environmental impacts to which they are exposed allow an exact and objective investigation of various constitutional and environmental factors in naevus development. As far as we are aware, this is the first published survey that simultaneously examines cutaneous and ocular pigmented lesions in an appreciable sample of identical and non-identical twins.

METHODS

172 pairs of twins of Caucasian origin were included in this study. A whole-body skin examination and a detailed ophthalmological examination were performed to determine the density of melanocytic lesions. A standardized questionnaire was used to assess the data relating to constitutional, sun exposure and other variables.

RESULTS

A notably high proportion of the subjects (36.78%) manifested one or more clinically atypical melanocytic naevi (CAMNs), and approximately one-third (31.4%) of them at least one benign uveal pigmented lesion (BUPL). The incidence of iris freckles (IFs), iris naevi (INs) and choroidal naevi (CHNs) proved to be 25.35%, 5.98% and 3.52%, respectively. The interclass correlation coefficients for common melanocytic naevi (CMNs), CAMNs, and INs were 0.77, 0.76 and 0.86 in monozygotic twins, as compared with 0.5, 0.27 and 0.25 in dizygotic twin pairs, respectively. A statistically significant correlation was found between the prevalence of CAMNs and that of INs.

CONCLUSIONS

This significant correlation suggests the existence of a subgroup of Caucasian people with an increased susceptibility to both cutaneous and ocular naevus formation. There is accumulating evidence that, besides the presence of cutaneous atypical naevi, INs can serve as a marker of a predisposed phenotype at risk of uveal melanoma. The correlation between cutaneous and ocular pigmented lesions underlines the need for the adequate ophthalmological screening of subjects with CAMNs and INs.

Uveal Spindle Cell Tumor of Blue-Eyed Dogs: An Immunohistochemical Study

Immunohistochemical techniques were used to investigate the origin of a spindle cell tumor in the anterior uveal tract of dogs and the influence of ultraviolet radiation on the development of this tumor. Thirteen tumors were identified from the 4,007 canine ocular samples examined at the Comparative Ocular Pathology Laboratory of Wisconsin between 1978 and 2005. Siberian Husky and Siberian Husky mix dogs were overrepresented (10/13 dogs, overall median age 10 years). Light microscopic evaluation (all dogs) and electron microscopy (2 dogs) were performed. Immunohistochemical staining included alpha-smooth muscle actin (SMA), vimentin, S-100, desmin, glial fibrillary acidic protein (GFAP), Melan A, microphthalmic transcription factor (MITF-1), protein gene product 9.5 (PGP 9.5), laminin, gadd45, p53, proliferating cell nuclear antigen (PCNA), anti-UVssDNA (antibody for detection of (6–4)-dipyrimidine photoproducts), and telomerase reverse transcriptase (TERT). All tumors occurred in the iris with or without ciliary body involvement and were composed of spindle cells arranged in fascicles and whorls (variable Antoni A and B behavior). All tumors were positive when immunostained for vimentin and S-100. Nine of 13 tumors exhibited GFAP immunopositivity. All tumors were negative for SMA, desmin, Melan A, and MITF-1. Tumors were variably positive for PGP 9.5, laminin, gadd45, p53, PCNA, anti-UVssDNA, and TERT. Electron microscopy revealed intermittent basal laminae between cells. These tumors are morphologically and immunohistochemically most consistent with schwannoma. The relationship between spindle cell tumors of the anterior uvea of dogs, altered neural crest, blue iris color, and ultraviolet radiation has not yet been fully elucidated.

Disparities in Uveal Melanoma: Patient Characteristics

Uveal melanoma is the most common intraocular malignancy in adults. Despite excellent rates of local control, half of all patients with uveal melanoma ultimately go on to develop fatal metastatic disease. This review focuses on disparities and differences in the underlying characteristics of the patients, and how these patient characteristics impact the development of metastasis and subsequent patient survival. Specifically, we detail disparities in epidemiology and risk factors as they relate to the development of primary uveal melanoma, to the development of metastasis, and to patient survival following metastasis.

Uveal Melanoma UK National Guidelines

The United Kingdom (UK) uveal melanoma guideline development group used an evidence based systematic approach (Scottish Intercollegiate Guidelines Network (SIGN)) to make recommendations in key areas of uncertainty in the field including: the use and effectiveness of new technologies for prognostication, the appropriate pathway for the surveillance of patients following treatment for primary uveal melanoma, the use and effectiveness of new technologies in the treatment of hepatic recurrence and the use of systemic treatments. The guidelines were sent for international peer review and have been accredited by NICE. A summary of key recommendations is presented. The full documents are available on the Melanoma Focus website.

Evidence for the Role of Blue Light in the Development of Uveal Melanoma

Uveal melanoma is the most common malignancy of the adult eye. Although it is a relatively infrequent tumor, clinical prognosis is often poor owing to a high incidence of aggressive metastatic disease, for which there are limited treatment options. Little is known about the etiology of this condition, although several risk factors have been identified. Unlike cutaneous melanoma, however, ultraviolet radiation does not figure prominently among these risk factors. In this review, we focus on an associated form of visible electromagnetic radiation, high-energy short-wave (blue) light, a causative agent in various forms of age-related retina damage, as a previously overlooked risk factor in uveal melanoma development and progression. Finally, we discuss the impact of these data on contemporary ocular therapy, particularly the debate surrounding the filtering capabilities of intraocular lenses used to replace dysfunctional crystalline lenses during cataract surgery.

Overview of dermatologic disorders of neonates in a central regional intensive care unit in Hungary

The immaturity and vulnerability of the skin and epidermal barrier function and the frequent iatrogenic complications following diagnostic and therapeutic procedures are often associated with skin manifestations in infants in neonatal intensive care units (NICUs). The aim of the current study was to investigate dermatologic disorders in neonates in our NICU. A prospective cohort study was conducted in the NICU at the Department of Pediatrics at the University of Szeged between January 2012 and January 2013. All full- and preterm infants hospitalized in the NICU underwent whole-body skin examinations and all dermatologic disorders and treatment modalities were recorded. Eighty-nine dermatologic conditions were detected in 64 of the 211 neonates admitted to the NICU. A wide variety of clinical symptoms accompanied these conditions in these preterm and severely ill full-term infants. A considerable proportion of the disorders that were seen resulted from the immaturity of the skin and various iatrogenic complications. Dermatologic disorders are frequent in neonates requiring intensive care. Prevention, early detection, and optimal treatment of these disorders with modern, standardized skin care management strategies can result in significant improvements in barrier function and in the integrity of the skin, increasing the overall efficacy of neonatal intensive care.

The enhancement of biological ocular UV radiation on beaches compared to the radiation on grass

BACKGROUND

The influence of albedo on ocular UV exposure has seldom been reported. This paper aimed to explore the enhancement effect on measured ocular UV radiation due to a sand surface compared to measured ocular UV radiation due to a grass surface.

METHODS

We measured ambient and ocular UV radiation over the beach and grass surface in Sanya City of China (18.4°N, 109.7°E). The experimental apparatus was composed of a manikin and a dual-detector spectrometer. Integration of both UVA and UVB radiation was used to denote UV radiation. Then biologically effective ocular UVB radiation (UVBE) and the ratios of UVBE of two surfaces were calculated.

RESULT

Maximum of ocular UV radiation versus time over the two surfaces is bimodal. UVBE on the beach is significantly larger than UVBE on the sand, and UVBE peaked at different solar elevation angle (SEA) over the two surfaces (about 53° and 40° on the beach and grass, respectively, according to Bayesian regression). The maximum of ocular UVBE ratios is greater than two, which peaked SEA was about 50°. One hour's cumulative radiation under sunny weather exceeds thresholds for photokeratitis, conjunctivitis and lens damage.

CONCLUSIONS

Higher albedo significantly increased biological ocular UV radiation. Tourists on tropical beaches should take protective measures and avoid facing the sun directly, especially when SEA is around 50°.

Eye cancer incidence in U.S. states and access to fluoridated water

Environmental risk factors for uveal melanomas (cancer of the iris, ciliary body, and choroid) have not been identified. To search for these, we examined the correlation of age-adjusted eye cancer incidence rates, a surrogate for uveal melanoma rates, in U.S. states with group level geographic and demographic factors using multivariate linear regression. Incidence rates for eye cancer were inversely correlated with the percentage of the population receiving fluoridated water; that is, higher rates were found in states with lower prevalences of fluoridation (P = 0.01). Fluoride is known to inhibit the growth of microbial agents that cause choroiditis and choroidal lesions in animals. We speculate that fluoridation protects against choroidal melanoma by inhibiting microbial agents that cause choroiditis and/or choroidal lesions in humans.

Mutation frequencies of GNAQ, GNA11, BAP1, SF3B1, EIF1AX and TERT in uveal melanoma: detection of an activating mutation in the TERT gene promoter in a single case of uveal melanoma

BACKGROUND

Uveal melanoma is the most frequent primary tumour of the eye. It is molecularly clearly distinct from cutaneous melanoma and shows a different pattern of driver mutations. The influence of sunlight ultraviolet (UV) exposure on the aetiology of uveal melanoma is a matter of debate. The recent identification of driver mutations in the promoter of the telomerase reverse transcriptase (TERT) gene with UV-induced cytidine-to-thymidine transitions in cutaneous melanoma prompted us to investigate whether these mutations also occur in uveal melanoma.

METHODS

We analysed 50 cases of uveal melanoma obtained from enucleation surgery for mutations in the genes GNAQ, GNA11, BAP1, SF3B1, EIFAX1 and TERT, measured gene expression using microarrays and analysed gene copy numbers by SNP arrays.

RESULTS

We detected a TERT mutation in only one case of a 57-year-old white male patient with clinical and histopathological features typical for uveal melanoma. The tumour showed mutations in GNA11 and EIF1AX that are typical for uveal melanoma and absent from cutaneous melanoma. No mutations were detected in GNAQ, BAP1 and SF3B1 that are frequently mutated in uveal melanoma. Both copies of chromosome 3 were retained. Several tumours among which the one carrying the TERT promoter mutation showed elevated TERT expression. Consistent with previous reports, GNAQ is inversely associated with chromosome 3 monosomy and metastasis. BAP1 mutations are significantly associated with chromosome 3 monosomy but not with relapse.

CONCLUSION

These data indicate that TERT mutations are rare in uveal melanoma. No conclusion can be drawn on their potential influence on tumour progression.

Treatment of primary intraocular melanoma

The treatment of intraocular melanoma has evolved recently. Enucleation has been superseded largely by brachytherapy, proton beam radiotherapy, stereotactic irradiation, trans-scleral local resection, transretinal resection and diode laser phototherapy. Many patients develop metastatic disease, which usually involves the liver and occurs hematogenously. Disseminated disease rarely responds to therapy, and is usually fatal within 1 year of the onset of symptoms. Uveal melanomas develop characteristic chromosomal abnormalities, such as loss of chromosome 3. This is associated with a reduction in the 5-year survival from approximately 95% to less than 50%.

Implication of ultraviolet light in the etiology of uveal melanoma: A review

Uveal melanoma is the most frequent intraocular cancer and the second most common form of melanoma. It metastasizes in half of the patients and the prognostic is poor. Although ultraviolet (UV) radiation is a proven risk factor for skin melanoma, the role of UV light in the etiology of uveal melanoma is still contradictory. We have compared epidemiological and genetic evidences of the potential role of UV radiation in uveal melanoma with data on cutaneous melanoma. Even though frequently mutated genes in skin melanoma (e.g. BRAF) differ from those found in uveal melanoma (i.e. GNAQ, GNA11), their mutation pattern bears strong similarities. Furthermore, we provide new results showing that RAC1, a gene recently found harboring UV-hallmark mutation in skin melanoma, is also mutated in uveal melanoma. This article aims to review the work done in the last decades to understand the etiology of uveal melanoma and discuss new avenues, which shed some light on the potential role of UV exposure in uveal melanoma.

SF3B1 mutations are associated with alternative splicing in uveal melanoma

Uveal melanoma, the most common eye malignancy, causes severe visual morbidity and is fatal in approximately 50% of patients. Primary uveal melanoma can be cured by surgery or radiotherapy, but the metastatic disease is treatment refractory. To understand comprehensively uveal melanoma genetics, we conducted single-nucleotide polymorphism arrays and whole-genome sequencing on 12 primary uveal melanomas. We observed only approximately 2,000 predicted somatic single-nucleotide variants per tumor and low levels of aneuploidy. We did not observe an ultraviolet radiation DNA damage signature, but identified SF3B1 mutations in three samples and a further 15 mutations in an extension cohort of 105 samples. SF3B1 mutations were associated with good prognosis and were rarely coincident with BAP1 mutations. SF3B1 encodes a component of the spliceosome, and RNA sequencing revealed that SF3B1 mutations were associated with differential alternative splicing of protein coding genes, including ABCC5 and UQCC, and of the long noncoding RNA CRNDE.

SIGNIFICANCE

Our data show that despite its dismal prognosis, uveal melanoma is a relatively simple genetic disease characterized by recurrent chromosomal losses and gains and a low mutational burden. We show that SF3B1 is recurrently mutated in uveal melanoma, and the mutations are associated with aberrant alternative splicing.

[Uveal melanoma: clinical characteristics, treatment and survival in a series of 500 patients]

OBJECTIVE

To analyse the clinical features, treatment and survival of uveal melanoma patients diagnosed in a referral Intraocular Tumours Unit over a twenty-year period.

METHODOLOGY

A prospective study was performed including five hundred patients, diagnosed between January 1992 and December 2011. Clinical tumour characteristics and treatment were collected in a database in Microsoft@ Access@. The numeric variables were expressed as means of frequency and standard deviation, and the quantitative variables using frequency tables.

RESULTS

The mean age of the sample was 62.19 years, with 51.2% females, and 64.2% presented with symptoms. The tumours were small in 31.12% of cases, and large in 23.09%, according to COMS criteria. Hazel green was the iris colour in 42.2% of the cases. The initial treatment was episcleral brachytherapy in 42.4% of the total. The overall mortality rate was 17% and 31.3%, and melanoma-related mortality rate was 11.6% and 14.8%, at 5 and 10 years, respectively.

CONCLUSIONS

In the serie studied melanomas were more frequent in women, and a higher proportion of darker irides were observed than in other previous studies. Most of the tumours were diagnosed when they became symptomatic and in the early or medium stages, allowing conservative therapies to be used, with brachytherapy being the predominant treatment. The melanoma-related mortality appeared to be lower than previously data published. However, further studies are required on the factors influencing survival.

TERT promoter mutations in ocular melanoma distinguish between conjunctival and uveal tumours

BACKGROUND

Recently, activating mutations in the TERT promoter were identified in cutaneous melanoma. We tested a cohort of ocular melanoma samples for similar mutations.

METHODS

The TERT promoter region was analysed by Sanger sequencing in 47 uveal (ciliary body or choroidal) melanomas and 38 conjunctival melanomas.

RESULTS

Mutations of the TERT promoter were not identified in uveal melanomas, but were detected in 12 (32%) conjunctival melanomas. Mutations had a UV signature and were identical to those found in cutaneous melanoma.

CONCLUSION

Mutations of TERT promoter with UV signatures are frequent in conjunctival melanomas and favour a pathogenetic kinship with cutaneous melanomas. Absence of these mutations in uveal melanomas emphasises their genetic distinction from cutaneous and conjunctival melanomas.

The role of optical radiations in skin cancer

Purpose. Electromagnetic radiation with wavelength in the range 100 nm to 1 mm is known as optical radiation and includes ultraviolet radiation, the visible spectrum, and infrared radiation. The deleterious short- and long-term biological effects of ultraviolet radiation, including melanoma and other skin cancers, are well recognized. Infrared radiation may also have damaging biological effects. Methods. The objective of this review was to assess the literature over the last 15 years and to summarize correlations between exposure to optical radiation and the risk of melanoma and other cancers. Results. There is a clear correlation between exposure to UV radiation and the development of skin cancer. Most importantly, a strong association between artificial UV radiation exposure, for example, tanning devices, and the risk of melanoma and squamous cell carcinoma has been clearly demonstrated. There is no clear evidence that exposure to IR and laser radiation may increase the risk of skin cancer, although negative health effects have been observed. Conclusions. Preventative strategies that involve provision of public information highlighting the risks associated with exposure to sunlight remain important. In addition, precautionary measures that discourage exposure to tanning appliances are required, as is legislation to prevent their use during childhood.

Neonatal blue light phototherapy and melanocytic nevi: a twin study

BACKGROUND

Neonatal blue light phototherapy (NBLP) has been widely and successfully used for the treatment of neonatal jaundice to reduce the plasma concentration of bilirubin and, hence, to prevent kernicterus. Only a few and controversial data are available in the literature as to how NBLP influences melanocytic nevus development.

OBJECTIVE

Our goal was to conduct a twin study with the aim of better understanding the role of NBLP in melanocytic nevus development. We also investigated the roles of other environmental and constitutional factors in nevus formation.

METHODS

Fifty-nine monozygotic and dizygotic twins were included in this cross-sectional study. One of the twin members received NBLP, and the other did not. A whole-body skin examination was performed to determine the density of melanocytic skin lesions. The prevalence of benign pigmented uveal lesions was evaluated during a detailed ophthalmologic examination. A standardized questionnaire was used to assess data relating to constitutional, sun-exposure, and other variables. To search for possible gene-environmental interactions involved in the appearance of pigmented lesions, the melanocortin 1 receptor variants and the I439V polymorphism of histidine ammonia-lyase genes were also determined in the enrolled twins.

RESULTS

NBLP was associated with a significantly higher prevalence of both cutaneous and uveal melanocytic lesions. No association was found between the examined gene polymorphisms and the number of pigmented alterations in the examined study group.

CONCLUSIONS

Our data suggest that NBLP could well be a risk factor for melanocytic nevus development. Phototherapy with blue-light lamps is a standard and essential therapeutic modality in neonatal care; therefore, additional in vivo and in vitro studies are necessary to establish its potential long-term adverse effects.

Uveal melanoma

Uveal melanoma is the most common primary intraocular malignancy and the leading primary intraocular disease which can be fatal in adults. In this paper epidemiologic, pathogenetic, and clinical aspects of uveal melanoma are discussed. Despite the advance in local ocular treatments, there has been no change in patient survival for three decades. Development of metastases affects prognosis significantly. Current survival rates, factors predictive of metastatic potential and metastatic screening algorithms are discussed. Proposed and emerging treatments for uveal melanoma metastases are also overviewed. Current advances in genetics and cytogenetics have provided a significant insight in tumours with high metastatic potential and the molecular mechanisms that underlie their development. Biopsy of those lesions may prove to be important for prognostication and to allow further research into genetic mutations and potential new therapeutic targets in the future.

Light-emitting diodes (LED) for domestic lighting: any risks for the eye?

Light-emitting diodes (LEDs) are taking an increasing place in the market of domestic lighting because they produce light with low energy consumption. In the EU, by 2016, no traditional incandescent light sources will be available and LEDs may become the major domestic light sources. Due to specific spectral and energetic characteristics of white LEDs as compared to other domestic light sources, some concerns have been raised regarding their safety for human health and particularly potential harmful risks for the eye. To conduct a health risk assessment on systems using LEDs, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), a public body reporting to the French Ministers for ecology, for health and for employment, has organized a task group. This group consisted physicists, lighting and metrology specialists, retinal biologist and ophthalmologist who have worked together for a year. Part of this work has comprised the evaluation of group risks of different white LEDs commercialized on the French market, according to the standards and found that some of these lights belonged to the group risk 1 or 2. This paper gives a comprehensive analysis of the potential risks of white LEDs, taking into account pre-clinical knowledge as well as epidemiologic studies and reports the French Agency's recommendations to avoid potential retinal hazards.

Spatial density of primary malignant melanoma in sun-shielded body sites: A potential guide to melanoma genesis

UV radiation is a major factor in melanoma genesis, but non-UV linked factors are also operational, since primary malignant melanomas can emerge in body sites that never see the sun. The scarcity of melanomas in sun-shielded body sites reflects only the absolute number of melanomas, not the number of tumours per square unit of the surface in which they emerge. Studies on melanoma density conducted by us and others are here briefly reviewed. The access to reliable numbers along with measurable anatomical areas directed our choice of melanomas at the sun-shielded locations described here. Melanomas at the body surface. Calculations of surface areas bearing melanomas relative to the total body surface included sites on the vulva, subungual tissues, volar and palmar skin, and, for comparison melanomas of the face during the same period of time. The density of vulvar melanomas was identical to that in chronically sun-exposed facial skin. Subungual melanomas were almost nine times denser than expected whereas melanomas of palms and soles showed a lower density than expected. Melanomas beneath the body surface. The densities of melanomas in the vagina, anal canal and uvea, were calculated separately and compared to the average density of cutaneous melanomas (CMMs) during the same period of time. Melanomas of the anal canal displayed a density almost twice the average for CMMs, whereas the vaginal melanomas were similar in density to CMMs. In contrast, the density of the uveal melanomas was calculated as 50 and 41 times (men and women, respectively) the average density of CMMs.

CONCLUSION

The high density of some melanomas in sun-shielded body areas indicates the presence of factors underlying the origins of these tumours that seem to be equivalent in strength to UV radiation and also implies that specific anatomical sites favour the emergence and proliferation of melanomas, independent of UV radiation.

Ultraviolet radiation: a hazard to children and adolescents

Sunlight sustains life on earth. Sunlight is essential for vitamin D synthesis in the skin. The sun's ultraviolet rays can be hazardous, however, because excessive exposure causes skin cancer and other adverse health effects. Skin cancer is a major public health problem; more than 2 million new cases are diagnosed in the United States each year. Ultraviolet radiation (UVR) causes the 3 major forms of skin cancer: basal cell carcinoma; squamous cell carcinoma; and cutaneous malignant melanoma. Exposure to UVR from sunlight and artificial sources early in life elevates the risk of developing skin cancer. Approximately 25% of sun exposure occurs before 18 years of age. The risk of skin cancer is increased when people overexpose themselves to sun and intentionally expose themselves to artificial sources of UVR. Public awareness of the risk is not optimal, compliance with sun protection is inconsistent, and skin-cancer rates continue to rise in all age groups including the younger population. People continue to sunburn, and teenagers and adults are frequent visitors to tanning parlors. Sun exposure and vitamin D status are intertwined. Adequate vitamin D is needed for bone health in children and adults. In addition, there is accumulating information suggesting a beneficial influence of vitamin D on various health conditions. Cutaneous vitamin D production requires sunlight, and many factors complicate the efficiency of vitamin D production that results from sunlight exposure. Ensuring vitamin D adequacy while promoting sun-protection strategies, therefore, requires renewed attention to evaluating the adequacy of dietary and supplemental vitamin D. Daily intake of 400 IU of vitamin D will prevent vitamin D deficiency rickets in infants. The vitamin D supplementation amounts necessary to support optimal health in older children and adolescents are less clear. This report updates information on the relationship of sun exposure to skin cancer and other adverse health effects, the relationship of exposure to artificial sources of UVR and skin cancer, sun-protection methods, vitamin D, community skin-cancer-prevention efforts, and the pediatrician's role in preventing skin cancer. In addition to pediatricians' efforts, a sustained public health effort is needed to change attitudes and behaviors regarding UVR exposure.

Atypically low spontaneous sister chromatid exchange formation in uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular cancer of adults and is characterized by several well-established chromosomal changes. More recently, a specific mutation of guanine nucleotide binding protein Gq alpha subunit (GNAQ) has also been identified in a proportion of UM. Although some of these alterations have been suggested to be early changes, the genetic alterations responsible for the development of UM have yet to be clearly determined. Cancers are characterized by increased genetic instability, and analysis of established cancer cell lines and blood from cancer patients has universally been associated with an increased level of sister chromatid exchange (SCE). We have observed that the spontaneous frequency of SCE in primary cultures of UM and UM-derived cell lines is decreased below normal baseline levels, a phenomenon unique to UM when compared with multiple other cancers. This finding was specific to the tumor and not found in lymphocytes from the patients. Although we cannot exclude the possibility that low SCE (LSCE) is peculiar to the uveal melanocytes lineage, as it was consistently observed in all UM studied, regardless of other genetic defects, we propose that this phenomenon contributes to the molecular pathogenesis of UM.