Integrating molecular biomarkers into current clinical management in melanoma

Expression of OPN3 in acral lentiginous melanoma and its associated with clinicohistopathologic features and prognosis

BACKGROUND

OPN3 upregulation associated with metastasis was recently described in two subtypes of lung cancers. And OPN3 identified in light-independent functions in epidermal melanocytes has already shown promise. However, in malignant melanocytic tissues, the expression and characterization of OPN3 remain uncharacterized.

OBJECTIVES

We investigated the clinico-histopathologic features in relation to OPN3 expression of acral lentiginous melanoma (ALM), which is a rare cutaneous melanoma subtype and not associated with prior sunlight exposure.

METHODS

In all, 84 samples of junctional melanocytic nevi (JMN, n = 12), primary ALMs (n = 39) and inguinal lymph node metastasis (ILNM, n = 23) from ALMs were evaluated for the immunohistochemical expression of OPN3. OPN3 messenger RNA and protein level were further determined in melanocytic tumors using quantitative real-time PCR, multiimmunofluorescence and Western blot assays. We also estimated the associations OPN3 expression between clinicopathological features and prognosis.

RESULTS

ILNMs, in contrast to JMN and ALMs, had higher OPN3 expression scores (p < .001) by immunohistochemistry analysis. High OPN3 score was associated with presence of ulceration, increased Breslow depth and Clark level (p = .025, p = .042, and p = .012, respectively). Furthermore, a remarkable difference (p = .037) of patient overall survival was found when comparing the OPN3 expression of immunohistochemical score between equal to or larger than 100 and below 100 groups. Also, Cox regression models showed that high OPN3 scores were associated with worse melanoma survival.

CONCLUSION

High OPN3 expression is significantly associated with ALMs and metastatic phenotype as well as a poor prognosis.

PLA1A expression as a diagnostic marker of BRAF-mutant metastasis in melanoma cancer

BRAF and NRAS are the most reported mutations associated to melanomagenesis. The lack of accurate diagnostic markers in response to therapeutic treatment in BRAF/NRAS-driven melanomagenesis is one of the main challenges in melanoma personalized therapy. In order to assess the diagnostic value of phosphatidylserine-specific phospholipase A1-alpha (PLA1A), a potent lysophospholipid mediating the production of lysophosphatidylserine, PLA1A mRNA and serum levels were compared in subjects with malignant melanoma (n = 18), primary melanoma (n = 13), and healthy subjects (n = 10). Additionally, the correlation between histopathological subtypes of BRAF/NRAS-mutated melanoma and PLA1A was analyzed. PLA1A expression was significantly increased during melanogenesis and positively correlated to disease severity and histopathological markers of metastatic melanoma. PLA1A mRNA and serum levels were significantly higher in patients with BRAF-mutated melanoma compared to the patients with NRAS-mutated melanoma. Notably, PLA1A can be used as a diagnostic marker for an efficient discrimination between naïve melanoma samples and advanced melanoma samples (sensitivity 91%, specificity 57%, and AUC 0.99), as well as BRAF-mutated melanoma samples (sensitivity 62%, specificity 61%, and AUC 0.75). Our findings suggest that PLA1A can be considered as a potential diagnostic marker for advanced and BRAF-mutated melanoma.

Recent developments in the medical and surgical treatment of melanoma

Increasing knowledge of the biology of melanoma has led to significant advances in drug development to fight this disease. Surgery is the primary treatment for localized disease and is an integral part of management in patients with more advanced disease. The last decade has become the era of targeted therapy in melanoma and has revolutionized the treatment of this disease. Since 2011, 4 new agents have been approved for the treatment of patients with metastatic melanoma: ipilimumab, vemurafenib, dabrafenib, and trametinib. Several new agents are currently in phase 3 trials with hopes of even more agents being approved for this once "untreatable" disease. How to integrate surgical options with more effective systemic therapies has become a new challenge for physicians. This review will provide an update on current surgical options, highlight the pathway to the development of the newly approved agents, and further discuss new treatments that are on the horizon.

Frontline approach to metastatic BRAF-mutant melanoma diagnosis, molecular evaluation, and treatment choice

An estimated 76,100 patients will be diagnosed with invasive melanoma in the United States in 2014, and 9,710 patients will die from the disease. In almost all cases, the cause of death is related to the development of widespread metastatic disease. Although death rates from most types of cancer have steadily decreased in the United States--a 20% decrease during two decades from a peak of 215.1 deaths per 100,000 population in 1991 to 171.8 in 2010--death rates from melanoma have steadily increased during the same time, especially among males. The news regarding melanoma is far from all bad. Increases in our understanding of the human immune system have led to the development of new immunotherapeutic drugs such as ipilimumab, which has been shown to improve survival in phase III trials in metastatic melanoma, and anti-programmed death 1 (anti-PD1) antibodies, recently hailed by ASCO as one of the past year's most noteworthy clinical cancer advances. However, no discovery has influenced and, indeed, transformed the management of metastatic melanoma more than the identifıcation of activating mutations in the BRAF gene in the mitogen-activated protein kinase (MAPK) pathway, which occur in about half of cutaneous melanomas and can be targeted with small molecule inhibitors of the BRAF protein, the downstream MEK protein, or both. This article will address how patients with metastatic melanoma are evaluated for their mutation status and how the presence of a targetable mutation influences therapeutic decisions regarding systemic therapy and even surgery.