Immunohistochemical expression of PRAME is a marker of poor prognosis in uveal melanoma: A clinico-pathologic and immunohistochemical study on a series of 85 cases

PRAME expression in fibrosarcomatous dermatofibrosarcoma protuberans

PRAME (PReferentially expressed Antigen in MElanoma) was first identified as a malignant melanoma-specific antigen. Recently, a few cases of fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP) were shown to have positivity for PRAME, while conventional dermatofibrosarcoma protuberans (C-DFSP) was negative. Because PRAME may be of diagnostic utility in FS-DFSP and is raising expectations as a new immunotherapy target, we examined the positivity of PRAME in FS-DFSP. Twenty-one cases of FS-DFSP and age/sex/location-matched cases of C-DFSP as a control group were examined by immunohistochemistry for CD34 and PRAME. The results were then evaluated by H-score, which was objectively and semi-quantitatively calculated using the open-source bioimaging analysis software QuPath. The results revealed that the PRAME H-score in FS-DFSP was significantly higher than that in C-DFSP (p = 0.0137). As for CD34, the H-score in FS-DFSP was significantly lower than that in C-DFSP (p < 0.001). Using these two immunohistochemical analyses in combination, the sensitivity and specificity for the diagnosis of FS-DFSP were 86% and 90%, respectively. Double staining of CD34 and PRAME revealed that PRAME-positive and CD34-positive areas did not overlap. This is the largest study to examine PRAME expression in FS-DFSP, and it confirmed the usefulness of PRAME in diagnosing this condition.

Mucosal Melanoma: Review from a Pathologist Point of View

Mucosal melanomas are rare malignant tumors arising from the epithelia lining the inner mucosal surfaces of the body. Unlike cutaneous melanoma, we have a limited understanding of mucosal melanomas is currently limited. Mucosal melanomas are characterized by genetic alterations quite distinct from cutaneous melanomas; however, their causative and promoting factors are unknown. These melanomas are characteristically diagnosed at a later stage due to their occult locations, leading to a worse prognosis. Dedicated staging systems for mucosal melanomas exist only for sinonasal and conjunctival melanomas. Therefore, risk stratification of patients with mucosal melanomas, particularly those arising from the anogenital area, is challenging. Recent studies have shown that minor modifications of the AJCC 8th Edition cutaneous melanoma staging system can group patients fairly robustly; however, the proposed T-categorization systems have yet to be validated in larger cohorts. We summarize the demographic, clinical, histopathologic, and molecular features of common subtypes of mucosal melanomas and highlight the outstanding needs in this field.

BAUSSS biomarker improves melanoma survival risk assessment

BACKGROUND

The American Joint Committee on Cancer (AJCC) method of staging melanoma is dated and inaccurate. It ignores important prognostic melanoma features, especially the patient's age. BAUSSS is more accurate in determining survival risk for primary cutaneous melanoma patients who have no clinical or imaging evidence of nodal or distant metastases. BAUSSS is an algorithm incorporating analysis of Breslow thickness, Age, Ulceration, Subtype of melanoma, Sex and Site. These are the six features from the patient history along with the details from the melanoma pathology report that are most predictive of mortality outcome.

OBJECTIVE

To develop a single-page document that allows the clinician to determine BAUSSS biomarker-predicted prognosis in consultation with the patient.

METHOD

From various data sources, we developed an algorithm to predict melanoma mortality using the BAUSSS biomarker system. The single-page algorithm was made available to download at https://globalmelanoma.net/bausss-survival-chart, thus being readily available without charge to all clinicians and their patients.

RESULTS

BAUSSS method of determining melanoma prognosis is more accurate and less costly than the AJCC staging system. The only surgery the patient requires is wide local excision of the primary tumour. This method of ascertaining melanoma risk does not require added surgery, costs, hospitalization, tests and anaesthesia, such as would be required if sentinel lymph node biopsy was undertaken. BAUSSS can be a useful tool in determining which primary melanoma patients are at sufficiently high risk to be considered for adjuvant drug therapy.

CONCLUSION

We encourage clinicians to download and print in colour this single-page BAUSSS mortality prediction tool, laminate it, and use it face to face with the patient in consultations. Not only will the patient be able to recognize his/her long-term prognosis but will also be able to see how their tumour severity compares with others.

A cuproptosis-related prognostic signature for guiding clinical diagnosis and treatment in uveal melanoma patients

Background

Cuproptosis, one of the most recently discovered forms of cell death, is induced by the disruption of copper binding to the mitochondrial respiratory acylation components. However, the mechanism underlying cuproptosis in uveal melanoma (UM) has not yet been adequately studied.

Methods

RNA and clinical data were obtained from The Cancer Genome Atlas (TCGA) database. Differentially expressed cuproptosis-related genes were identified by R software. A prognostic signature was constructed by applying LASSO regression and Cox regression models. The associations between the signature and the immune microenvironment, overall survival, and drug sensitivity were studied. In addition, qPCR and Western blotting were performed on UM cells and RPE cell lines to verify the expression levels of the genes encoding dihydrolipoamide dehydrogenase (DLD) and dihydrolipoamide S-succinyltransferase (DLST) in UM cases.

Results

Using a cuproptosis-related prognostic signature, UM samples were classified into high- and low-risk groups. A significant difference in overall survival between the two risk groups was evident. Receiver operating characteristic curves demonstrated that the signature is a reliable predictor of prognosis. Immune cell infiltration, drug sensitivity, and immune checkpoint expression were analysed. Significant immune difference between the two high-risk groups was found, and the high expression of immune checkpoints in high-risk groups suggests significant immunotherapy potential. In addition, drug sensitivity analysis experiments suggest that erlotinib may be a potential treatment for high-risk patients. The results of in vitro experiments confirmed that DLD and DLST had higher expression levels in UM cell lines.

Conclusions

The prognostic signature developed in this study is a reliable biomarker for predicting the prognosis of UM and may serve as a tool for personalised treatment of patients with UM.

PRAME Updated: Diagnostic, Prognostic, and Therapeutic Role in Skin Cancer

Preferentially Expressed Antigen in Melanoma (PRAME), a member of the cancer/testis antigen family, is central to the field of skin cancer diagnostics and therapeutics. As a nuclear receptor and transcriptional regulator, PRAME plays a critical role in inhibiting retinoic acid signalling, which is essential for cell differentiation and proliferation. Its aberrant overexpression in various malignancies, particularly cutaneous melanoma, is associated with more aggressive tumour phenotypes, positioning PRAME as both a diagnostic and prognostic marker. In melanoma, PRAME is typically highly expressed, in contrast to its weak or absent expression in benign nevi, thereby improving the accuracy of differential diagnoses. The diagnostic value of PRAME extends to various lesions. It is significantly expressed in uveal melanoma, correlating to an increased risk of metastasis. In acral melanomas, especially those with histopathological ambiguity, PRAME helps to improve diagnostic accuracy. However, its expression in spitzoid and ungual melanocytic lesions is inconsistent and requires a comprehensive approach for an accurate assessment. In soft tissue sarcomas, PRAME may be particularly helpful in differentiating melanoma from clear cell sarcoma, an important distinction due to their similar histological appearance but different treatment approaches and prognosis, or in detecting dedifferentiated and undifferentiated melanomas. In non-melanoma skin cancers such as basal cell carcinoma, squamous cell carcinoma, and Merkel cell carcinoma, the variable expression of PRAME can lead to diagnostic complexity. Despite these challenges, the potential of PRAME as a therapeutic target in melanoma is significant. Emerging immunotherapies, including T-cell-based therapies and vaccines targeting PRAME, are being investigated to exploit its cancer-specific expression. Ongoing research into the molecular role and mechanism of action of PRAME in skin cancer continues to open new avenues in both diagnostics and therapeutics, with the potential to transform the management of melanoma and related skin cancers.

Cancer/Testis Antigens as Targets for RNA-Based Anticancer Therapy

In the last few decades, RNA-based drugs have emerged as a promising candidate in the treatment of various diseases. The introduction of messenger RNA (mRNA) as a vaccine or therapeutic agent enables the production of almost any functional protein/peptide. The key to applying RNA therapy in clinical trials is developing safe and effective delivery systems. Exosomes and lipid nanoparticles (LNPs) have been exploited as promising vehicles for drug delivery. This review discusses the feasibility of exosomes and LNPs as vehicles for mRNA delivery. Cancer/testis antigens (CTAs) show restricted expression in normal tissues and widespread expression in cancer tissues. Many of these CTAs show expression in the sera of patients with cancers. These characteristics of CTAs make them excellent targets for cancer immunotherapy. This review summarizes the roles of CTAs in various life processes and current studies on mRNAs encoding CTAs. Clinical studies present the beneficial effects of mRNAs encoding CTAs in patients with cancers. This review highlight clinical studies employing mRNA-LNPs encoding CTAs.