World Health Organization experience in the treatment of melanoma

An indirect treatment comparison of the efficacy of pembrolizumab versus competing regimens for the adjuvant treatment of stage III melanoma

Objective: To determine the efficacy of pembrolizumab relative to other treatments used in stage III melanoma by conducting a systematic literature review (SLR) and network meta-analysis (NMA).

Methods: A SLR was conducted to identify randomized clinical trials (RCTs) evaluating approved adjuvant treatments including interferon-containing regimens, BRAF-inhibitors, and PD-L1 inhibitors in stage III melanoma patients. Relative treatment effects for recurrence-free survival (RFS) were synthesized with Bayesian NMA models that allowed for hazard ratios (HRs) to vary over time.

Results: Included studies formed a connected network of evidence composed of eight trials. In high-risk stage III patients, the HR for pembrolizumab vs observation decreased significantly over time with the superiority of pembrolizumab over observation becoming statistically meaningful before 3 months. By 9 months, the HR for pembrolizumab vs observation was statistically significantly lower than the HR for most other treatments vs observation, with the exception of ipilimumab and biochemotherapy due to overlapping 95% credible intervals. In BRAF + patients, pembrolizumab was statistically significantly better than observation after 3 months. The HR for both BRAF-inhibitors vs observation increased significantly over time and pembrolizumab was statistically superior to both BRAF-inhibitors after 15 months.

Conclusions: Pembrolizumab results in statistically significantly improved RFS compared to all competing regimens after 9 months, except ipilimumab and biochemotherapy, for the adjuvant treatment of stage III melanoma. However, point estimate HRs vs observation for pembrolizumab are much lower than those for ipilimumab. In BRAF + patients, the advantage of pembrolizumab versus competing interventions increases over time with respect to RFS.

The pathology of melanoma

Although melanoma represents only 10% of all skin cancer diagnoses, it accounts for at least 65% of all skin cancer-related deaths. The number of new cutaneous melanoma cases projected during 2010 was 68,000-a 23% increase from the 2004 prediction of 55,100 cases. In 2015, the lifetime risk of developing melanoma is estimated to increase to 1 in 50. As the incidence of melanoma continues to rise, now more than ever, clinicians and histopathologists must have familiarity with the various clinical and pathologic features of cutaneous melanoma.

The CSPG4-specific monoclonal antibody enhances and prolongs the effects of the BRAF inhibitor in melanoma cells

PLX4032 is a BRAF-selective inhibitor shown to be efficacious in the treatment of melanomas presenting with the BRAF(V600E) mutation. However, favorable responses to treatment are short-lived, and complete remission is rarely observed. Therefore, it is important to identify novel therapies designed to enhance treatment responses and to increase the longevity of initial response to BRAF inhibitors. To this end, we characterized the effects of the 225.28 chondroitin sulfate proteoglycan 4 (CSPG4)-specific monoclonal antibody (mAb) capable of blocking multiple signaling pathways important to cell growth, migration, and survival. Addition of 225.28 to the treatment regimen enhanced the in vitro response magnitude and the duration efficacy of PLX4032 in treating CSPG4(+), BRAF(V600E) melanoma cells (melanoma(BRAF(V600E)/CSPG4+) cells). Data presented in this report demonstrated that (1) treatments comprised of PLX4032 and mAb 225.28 were more effective at inhibiting melanoma(BRAF(V600E)/CSPG4+) cell growth than either agent alone, (2) mAb 225.28 prevented/delayed the development of resistance in melanoma(BRAF(V600E)/CSPG4+) cells to PLX4032, and (3) the mechanism of action of the combination therapy caused a down-regulation in multiple signaling pathways. This study provides a foundation for future investigations designed to improve BRAF inhibitor effectiveness in vitro and in vivo for treating melanoma(BRAF(V600E)/CSPG4+) cells in combination with a CSPG4-specific mAb.

Functional and clinical relevance of chondroitin sulfate proteoglycan 4

The lack of effective conventional therapies for the treatment of advanced stage melanoma has stimulated interest in the development of novel strategies for the management of patients with malignant melanoma. Among them, immunotherapy has attracted much attention because of the potential role played by immunological events in the clinical course of melanoma. For many years, T cell-based immunotherapy has been emphasized in part because of the disappointing results of the monoclonal antibody (mAb)-based clinical trials conducted in the early 1980s and in part because of the postulated major role played by T cells in tumor growth control. More recently, mAb-based therapies have gained in popularity given their clinical and commercial success for a variety of malignant diseases. As a result, there has been increased interest in identifying and characterizing antibody-defined melanoma antigens. Among them, the chondroitin sulfate proteoglycan 4 (CSPG4), also known as high molecular weight-melanoma associated antigen (HMW-MAA) or melanoma chondroitin sulfate proteoglycan (MCSP), has attracted much attention in recent years because of the growing experimental evidence that it fulfills two requirements for immunotherapy to be therapeutically effective: (1) targeting of cancer stem cells (CSC) and (2) development of combinatorial therapies to counteract the escape mechanisms driven by the genetic instability of tumor cells. With this in mind, in this chapter, we have reviewed recent information related to the distribution of CSPG4 on various types of tumors, including CSC, its expression on pericytes in the tumor microenvironment, its recognition by T cells, its role in cell biology as well as the potential mechanisms underlying the ability of CSPG4-specific immunity to control malignant cell growth.

Cutaneous head and neck melanoma: the old and the new

The incidence rate of malignant melanoma has shown a rapid worldwide rise in recent years. The staging and management of head and neck melanoma presents some unique challenges. Surgery remains the cornerstone of treatment, while sentinel node biopsy is the most accurate staging modality for regional disease. The complex regional anatomy and lymphovascular drainage of this region may account for the increased biologic aggressiveness and treatment challenges of this disease. Improved understanding of the radiobiology of melanoma has resulted in new adjuvant radiotherapy approaches, yielding improved control rates. The treatment outcomes of metastatic head and neck melanoma remain disappointing but important progress has been made in the understanding of melanoma biology.

Dupla drenagem para cadeias linfonodais distintas, detectada por técnica de biópsia de linfonodo sentinela em pacientes com melanoma cutâneo: relato de dois casos

Os principais méritos da biópsia de linfonodo sentinela em pacientes com melanoma cutâneo residem na possibilidade de serem evitadas linfadenectomias radicais desnecessárias e de permitir a correta identificação da cadeia de drenagem linfática, principalmente quando o tumor se localiza em áreas de drenagem ambígua. Atualmente já foi incorporada como fator prognóstico, sendo importante dado para o correto estadiamento do paciente. No presente relato são apresentados dois casos em que a utilização desta técnica foi extremamente útil, sobretudo por ter identificado a presença de drenagem linfática para duas cadeias linfáticas distintas. é importante que o dermatologista esteja consciente da correta indicação da técnica, para poder orientar da melhor forma possível seus pacientes.

Melanoma of the head and neck

Staging of cutaneous melanoma has changed in recent years with an increased emphasis upon thickness and ulceration on prognosis of early stage disease. Cutaneous melanoma of the head and neck is treated with complete surgical resection in early stage disease. Resection margins are determined by the size, depth, and presence of satellite lesions. Evaluation for regional and distant metastatic disease is necessary in all cases of advanced stage disease. Sentinel lymph node biopsy and possible parotidectomy and neck dissection should be considered in head and neck cutaneous melanomas greater than 1 mm in thickness or with ulceration. Adjuvant therapy may be indicated in advanced primary, nodal, and metastatic disease. Mucosal melanoma of the head and neck remains a difficult disease to treat, with high locoregional recurrence rates and poor prognosis despite aggressive therapy.

Molecular detection of circulating tumor cells is an independent prognostic factor in patients with high-risk cutaneous melanoma

Detection of circulating tumor cells (CTCs) might improve current staging procedures by identifying a subgroup of patients with minimal residual disease and thus a higher risk of disease recurrence. Forty patients with > or =2-mm-thick cutaneous melanoma with or without lymph node metastasis were enrolled. After standard radical surgery and adjuvant therapy in case of lymph node metastasis, patients were followed up with routine physical and radiologic assessments as well as serial PCR-based analysis of CTCs using 2 melanoma markers (tyrosinase and Melan-A/Mart-1). After a median follow-up of 30 months, 18 patients had disease recurrence and 28 were PCR-positive before the disease became clinically evident. The sensitivity of the molecular test was 83%. Median time to PCR positivity and median PCR-to-relapse time were 12 and 8 months, respectively. At multivariate analysis, PCR positivity was an independent predictor of disease recurrence (hazard ratio=2.06, 95% CI 1.07-3.35; p=0.03). Among high-risk melanoma patients, serial PCR-based analysis of CTCs can identify a subgroup at higher risk of disease recurrence, with clinically significant advance. Therefore, CTC detection might be employed for the selection of patients for adjuvant treatment and during follow-up for early indication of therapeutic failure.

Selective sentinel lymphadenectomy for malignant melanoma

To date, selective sentinel lymphadenectomy (SSL) should be considered a standard approach for staging patients with primary invasive melanoma greater than or equal to 1 mm. It is imperative that the multidisciplinary team master the techniques of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and postoperative pathologic evaluation of the sentinel lymph nodes (SLNs). A SLN is defined as a blue, "hot", or any subsequent lymph node greater than 10% of the in vivo count of the hottest lymph node and as an enlarged or indurated lymph node. Frozen sections are not recommended. For extremity melanoma, delayed SSL may be performed. Preoperative lymphoscintigraphy for extremity melanoma may be done the night before so that surgery can be scheduled as the first case of the following day. Every surgeon who uses blue dye should be cognizant of the potential adverse reaction to isosulfan blue and treatment for such a potential fatal reaction. A complete lymph node dissection is done if the SLN is found to be positive. Elective lymph node dissection should not be done if SSL can be done as a staging procedure. It is important for investigators involved with SSL to follow the clinical outcome of their patients so that the role of SSL can be further defined.