Adjuvant therapy for cutaneous malignant melanoma

Inhibitors of melanogenesis increase toxicity of cyclophosphamide and lymphocytes against melanoma cells

High mortality rate for metastatic melanoma is related to its resistant to the current methods of therapy. Melanogenesis is a metabolic pathway characteristic for normal and malignant melanocytes that can affect the behavior of melanoma cells or its surrounding environment. Human melanoma cells in which production of melanin pigment is dependent on tyrosine levels in medium were used for experiments. Peripheral blood mononuclear cells were derived from the buffy coats purchased from Lifeblood Biological Services. Cell pigmentation was evaluated macroscopically, and tyrosinase activity was measured spectrophotometrically. Cell proliferation and viability were measured using lactate dehydrogenase release MTT, [(3)H]-thymidine incorporation and DNA content analyses, and gene expression was measured by real time RT-PCR. Pigmented melanoma cells were significantly less sensitive to cyclophosphamide and to killing action of IL-2-activated peripheral blood lymphocytes. The inhibition of melanogenesis by either blocking tyrosinase catalytic site or chelating copper ions sensitized melanoma cells towards cytotoxic action of cyclophosphamide, and amplified immunotoxic activities of IL-2 activated lymphocytes. Exogenous L-DOPA inhibited lymphocyte proliferation producing the cell cycle arrest in G1/0 and dramatically inhibited the production of IL-1beta, TNF-alpha, IL-6 and IL-10. Thus, the active melanogenesis could not only impair the cytotoxic action of cyclophosphamid but also has potent immunosuppressive properties. This resistance to a chemotherapeutic agent or immunotoxic activity of lymphocytes could be reverted by the action of tyrosinase inhibitors. Thus, the inhibition of melanogenesis might represent a valid therapeutic target for the management of advanced melanotic melanomas.

Cutaneous melanoma: pathogenesis and rationale for chemoprevention

OBJECTIVE

To critically review aspects of melanoma pathogenesis that lend themselves to a chemoprevention strategy. To discuss potential candidate chemoprevention agents with an emphasis on the lipid lowering drugs, the statins, currently, the most promising agents.

DATA SOURCES

A retrospective review of the literature.

STUDY SELECTION

Studies included those relevant to melanoma pathogenesis, to the scientific rationale of chemoprevention, and pertinent epidemiologic, pre-clinical, and clinical studies. The referenced study designs and methodologies varied.

DATA EXTRACTION AND SYNTHESIS

Data were extracted by two reviewers, and the main results are presented in a quantitative descriptive manner.

CONCLUSION

Melanoma is a preventable disease by altering behavior (sun exposure) among at-risk individuals. There is also considerable evidence to suggest that melanoma development may be prevented or delayed by drugs of sufficiently low toxicity to make clinical trials of chemoprevention feasible and potentially successful. Among potential candidate agents, statins have compelling data for long-term safety and sufficient pre-clinical and clinical evidence for efficacy to justify their evaluation in well-designed trials in high-risk individuals, incorporating intermediate biologic endpoints.

Current concepts in the management of patients with melanoma

Melanoma is a significant health problem. Despite public education and free cancer screenings, the incidence and mortality of melanoma continues to rise; however, many currently diagnosed melanomas are thin lesions, suggesting that education and awareness is having an impact. In addition, there are still subsets of patients who need increased surveillance in order to increase their survival. Although large congenital nevi may be precursors of melanoma, small and medium congenital nevi have an insignificant risk for melanoma development. Large congenital nevi, which are axial in location, appear to be more likely to develop melanoma and are associated with melanocytosis and melanoma of the CNS, both of which portend a poor prognosis. Recently, the recommended margins of excision have become more conservative so that many of the surgical defects can be closed primarily. Lymphoscintigraphy and sentinel node biopsy have replaced elective node dissections, thus decreasing the morbidity associated with the surgical management of melanoma. Although controversy still exists as to whether or not sentinel lymph node biopsy alters a patient's prognosis, it has been shown to be a powerful prognostic indicator. Although most melanomas are managed by routine surgical excision, other modalities are sometimes employed. For example, cryosurgery or radiation therapy may be indicated in the frail, elderly individual with a large facial lentigo maligna. Mohs surgery is the treatment of choice for head and neck melanomas and those located in areas where maximum preservation of tissue is required and for desmoplastic and acral lentiginous melanomas. Much more work remains in the area of adjuvant therapy, chemotherapy, and immunotherapy. Dacarbazine remains the drug of choice in disseminated melanoma, but remissions are usually short lived. Interleukin and biochemotherapy has yielded good results but the percentage benefiting is small. Although high dose interferon increases disease-free and overall survival in some patients, it remains a controversial drug which is not easily tolerated. In the new staging system for melanoma, ulceration is second only to Breslow's thickness. In transit (satellite) lesions have also been included in this new system. The new system also recognizes that patients with only microscopic metastatic nodal disease fare better than patients with clinically enlarged metastatic nodes and that it is the number of nodes involved with metastases, not their size, that determines the patient's prognosis. Except for lesions <1mm thick, the Clark's level of invasion has been de-emphasized.

Malignant melanoma

CONTEXT

The rapidly developing fields of melanoma research are revolutionizing the current concepts on melanoma etiology and pathogenesis and are introducing newer diagnostic techniques and potential therapeutic approaches.

OBJECTIVES

To present the most current concepts on the etiology and pathogenesis of melanoma and to introduce the recent diagnostic techniques and the potential therapeutic approaches.

METHODS

Data sources were reports on melanoma published in the English language literature and observations made using specimens available at Harvard University, Johns Hopkins Medical Center, Albany Medical College, Loyola University Medical Center, and University of Tennessee Health Science Center.

RESULTS

Studies on melanoma containing chromosomal or genetic evaluation were selected for further analysis. Current clinical and pathologic categories with the reported genetic abnormalities were related to the latest information on pigment biology. The data extracted were used to develop a conceptual framework on the pathogenesis of melanoma; the generated model was then evaluated and used to suggest potential therapeutic approaches.

CONCLUSIONS

(1) Melanoma is not genetically homogeneous, and the existing differences between the pathologic categories, particularly in areas such as type of growth phase (radial vs vertical growth), total vertical dimension, ulceration of primary tumor, and metastatic process, have profound prognostic and therapeutic implications. (2) Chromosomal aberrations and gene mutations are found in sporadic and familial melanomas; among the most important are those affecting the 9p21, which contains the p16 locus, a site known to be critical for normal progression of the cell cycle. Aberrant p16 expression is associated with more aggressive behavior. (3) Melanoma cells possess a remarkable repertoire of biosynthetic capacities represented by the production of hormones, growth factors, and their receptors that may sustain and accelerate tumor development and progression. For example, expression of the tumoral products alpha-melanocyte-stimulating hormone and adrenocorticotropic hormone is regulated in vitro by ultraviolet light, a known carcinogen. (4) Melanomas differ from other tumors in their intrinsic capability to express melanogenic enzymes with the corresponding structural proteins to actually synthesize melanin. Melanogenesis-related proteins are rapidly entering the clinical arena, being used not only as diagnostic markers, but also as potential targets for melanoma therapy.

Nail apparatus melanoma

Nail apparatus melanoma is a relatively rare variant of melanoma with a disproportionately high mortality when compared with melanoma elsewhere. The aetiology and natural history remain poorly understood. There is no clear epidemiological association with race, skin type or sun exposure. Universally accepted clinical and histological criteria for the diagnosis of early nail apparatus melanoma have not been defined. The two cardinal clinical signs are melanonychia striata and Hutchinson's sign. These are useful but not pathognomonic of melanoma. Diagnostic delay is frequent and patients commonly have advanced disease at the time of diagnosis. Surgical excision is advocated for treatment of stage I disease; however, the most appropriate re-excision margins, including the level of amputation where required, have not been determined. Early diagnosis and excision of the tumour is the only treatment known to increase survival. Adjuvant systemic chemotherapy, isolated limb perfusion, and routine elective lymph node dissection have been used, but no survival benefit has been demonstrated.

Cost-effectiveness analysis of interferon as adjuvant therapy in high-risk melanoma patients in Spain

In the randomised clinical trial E1684, the administration of interferon (IFN) alpha-2b resulted in prolonged disease-free and overall survival in high-risk melanoma patients following surgical resection. However, and considering the cost and toxicity of IFN, the convenience of its widespread use should be evaluated. The aim of this study was to analyse the cost-effectiveness ratio of adjuvant therapy with IFN alpha-2b in melanoma patients versus an untreated control group. A Markov model was used to compare two hypothetical cohorts of 1000 patients aged 50 years, according to the clinical outcome of the E1684 study. The cohort of patients treated with IFN alpha-2b has an increased overall survival of 1.90 years during the patient's lifetime. The incremental discounted cost per life year gained of IFN versus observation is 9015 Euros according to the projection generated by the model. The sensitivity analysis demonstrated that changes in the most relevant study end-points do not modify the study outcome. In conclusion, in high-risk melanoma patients following surgical resection, the cost-effectiveness of IFN alpha-2b (at a dose of 20 MU/m2/day, 5 days per week for one month, followed by 10 MU/m2 TIW, up to one complete year of therapy) versus an untreated control group is within the limits established in health economics to determine if adoption of a new treatment is economically justified and is comparable with other interventions in which cost-effectiveness is acceptable to the National Health System.

The use of interferon alfa as adjuvant therapy for advanced cutaneous melanoma: the need for more evidence

Interferon alfa is rapidly gaining acceptance as the standard of care for patients with advanced but nonmetastatic cutaneous malignant melanoma. The randomized trials of interferons for melanoma are reviewed with attention to any survival benefits demonstrated by these studies. Because none of these studies are placebo controlled, questions regarding the placebo effects interferons may possess are addressed, as is an analogous clinical scenario in which interferons appeared to be beneficial in nonplacebo controlled trials but were shown to be ineffective in placebo-controlled trials. Moreover, given the significant toxicities and financial costs of interferons, the argument is advanced that interferon alfa should not become the standard of care for melanomas until the results of randomized, placebo-controlled trials evaluating the survival advantages of interferon alfa for melanoma become available.

Advances in specific immunotherapy of malignant melanoma

Management of malignant melanoma continues to present a challenge to dermatologists, particularly in advanced cases. In light of the steady increase in the worldwide incidence and mortality rates for melanoma, better understanding of the immune mechanisms regulating melanoma progression and interaction with the host's immune system seems eminently important. New studies on the role of immune mechanisms in the pathogenesis and clinical course of melanoma have recently been published. We review the immune mechanisms involved in tumor progression and ways in which these mechanisms may be applied toward immunotherapeutic management of malignant melanoma.

LEARNING OBJECTIVE

After the completion of this learning activity, participants should be familiar with (1) the immune mechanisms involved in host-tumor interaction and tumor rejection, (2) factors allowing the escape of melanoma cells from immune recognition, and (3) the current rationale for the different types of specific immunotherapy in melanoma. Better understanding of basic mechanisms in tumor immunology should raise awareness of future immunotherapeutic approaches in patients with melanoma, particularly in those who are at high risk of recurrence or who present with advanced disease.

Wild-type p53 gene transfer inhibits invasion and reduces matrix metalloproteinase-2 levels in p53-mutated human melanoma cells

The tumor suppressor gene p53 has inhibitory effects on cell growth and angiogenesis and induces apoptosis when overexpressed in melanoma and in a variety of tumor cells by adenovirus-mediated gene transfer. The invasive ability of tumor cells, facilitating local infiltration and metastasis, is related to matrix metalloproteinase levels. In melanoma, matrix metalloproteinase-2 and matrix metalloproteinase-9 have a prominent role in this process. The aim of this study was to evaluate whether wild-type p53 overexpression, obtained by a recombinant adenovirus vector (AdCMV.p53), affects cell invasiveness through modulation of matrix metalloproteinase-2 and matrix metalloproteinase-9. Two human melanoma cell lines were used in this study: the SK-MEL-110, carrying a mutated p53 gene, and the SK-MEL-147, carrying the wild-type p53 gene. SK-MEL-110 cells infected with AdCMV.p53 exhibited decreased invasion capability from day 1 after infection, compared with cells not infected or infected with the control vector AdCMV.Null. This reduced invasiveness was associated with decreased matrix metalloproteinase-2 levels in conditioned media whereas no changes were detected in matrix metalloproteinase-9 secreted levels. No modulation in matrix metalloproteinase-2 mRNA levels was detectable, however, after wild-type p53 gene transfer. Furthermore, protein expression of secreted tissue inhibitor of metalloproteinase-2 was not altered by AdCMV.p53 treatment. In contrast, in SK-MEL-147 cells, AdCMV.p53 did not affect cell invasiveness and levels of secreted matrix metalloproteinase-2. Gene transfer of wild-type p53 inhibited proliferation of both cell lines, showing that also SK-MEL-147 cells respond to wild-type p53 overexpression. This novel mechanism of action of wild-type p53 gene transfer may contribute to its antitumor effect by downregulating cell invasion and matrix metalloproteinase-2 secreted levels in mutated p53 human melanoma cell lines.

Nail melanoma: a review of the literature with recommendations to improve patient management

In this review, the current state of knowledge concerning nail melanoma is summarized. The pathogenesis, histological findings, clinical presentation, treatment and prognosis of this rare form of cutaneous melanoma are discussed. Important clinical clues to the early diagnosis of nail melanoma are highlighted and recommendations to improve the management of patients are suggested.

Malignant melanoma

The incidence of malignant melanoma is increasing at a rate greater than any other cancer occurring in humans. In this era of managed care, patients with a suspicious pigmented lesion may first present to their primary care physician for evaluation. Therefore it is mandatory that the primary care physician be capable of distinguishing between benign and malignant pigmented lesions, know how to evaluate such patients, and know when to refer patients with suspicious or malignant pigmented lesions. Surgical removal remains the mainstay of treatment for patients with melanoma. Thus, to increase the cure rate for melanoma, both the public and nondermatologists need to be educated regarding the prevention and early detection of melanoma. Only in this way can the diagnosis of melanoma be made early before deep invasion has occurred and the patient placed at risk for systemic spread. In recent years, the surgical management of melanoma has become more conservative and rational. Limb amputation, arbitrary 5-cm margins of excision, and elective lymph node dissections are no longer performed. The recommended margins of excision are now based on objective pathologic and clinical data and are more conservative, and the sentinel node biopsy is now used to determine which high-risk patients should undergo a formal lymph node dissection. Although encouraging results are being seen with immunotherapy protocols, to date the only adjunctive therapy shown to increase survival in patients at high risk for systemic spread is alpha-interferon. With this drug, the improved survival is modest at best; it is expensive and a minority of patients can tolerate it in the doses recommended. Although response rates of 20% are seen with chemotherapy in patients with disseminated disease, these responses are short-lived, and there is no associated increased survival. Except for lentigo maligna, radiation therapy, even when its delivery is modified, still is useful only as an adjunct to surgery or for palliation.

Vaccines and other adjuvant therapies for melanoma

Patients with thick primary melanomas or regional lymph node involvement are at high risk of relapse. Investigations of adjuvant therapy over the past 30 years show only one significantly positive trial employing high dose interferon-alpha-2b. This is a potentially toxic regimen, therefore, other better-tolerated forms of adjuvant immunotherapy are being studied. Recent advances in basic science have led to a better understanding of the T-cell response to human cancer. This article discusses the background and current clinical trials of active specific immunotherapies for melanoma, including peptide and ganglioside vaccines.

The incidence and prognosis of nail apparatus melanoma. A retrospective study of 105 patients in four English regions

Our population-based study establishes epidemiological data on age-specific incidence rates, clinical presentation, Breslow microstaging, treatment and survival of nail apparatus melanoma (NAM) patients in England. Four cancer registries, covering a population of 10.6 million, recorded 105 cases of NAM during the period 1984-93. During the same decade there was a total of 7585 patients with cutaneous melanoma and NAM represents 1.4% of all cutaneous melanoma. The incidence rate of NAM in English patients is 0.1 per 100,000 of the population per annum. Amelanotic melanoma was the clinical presentation in 24 of our NAM cases. The overall prognosis is poor with an observed 5 year survival of only 51%. Patients with NAM less than 2.5 mm Breslow depth have a 5 year survival of 88% and are twice as likely to survive compared with those with tumours greater or equal to 2.5 mm in thickness (P < 0. 05). NAM patients are best managed by a multidisciplinary team approach in a few key skin cancer centres.

An estimate of the annual direct cost of treating cutaneous melanoma

BACKGROUND

Although the survival benefits of early stage melanoma have been clearly documented, the potential economic impact of early versus late stage disease has not been assessed.

OBJECTIVE

Our purpose was to estimate the annual direct cost of diagnosing and treating melanoma, based on the number of projected cases of melanoma entering each stage in 1997.

METHODS

A model was constructed with assumptions derived from the literature and clinical experience at the Massachusetts General Hospital Melanoma Center and the Boston University Medical Center. Cost estimates were based on 1997 Boston area Medicare reimbursements.

RESULTS

The annual direct cost of treating newly diagnosed melanoma in 1997 was estimated to be $563 million. Stage I and II disease each comprised about 5% of the total cost; stage III and stage IV disease consumed 34% and 55% of the total cost, respectively. About 90% of the total annual direct cost of treating melanoma in 1997 was attributable to less than 20% of patients (those patients with advanced disease, that is, stage III and stage IV).

CONCLUSION

In addition to the potential survival advantages, aggressive primary prevention through sun protection and intensive screening to enhance earlier detection should reduce the economic burden of melanoma care.

Advances in melanoma therapy

This review discusses several advances in melanoma therapy that have recently occurred or are presently in a developmental stage. We discuss the history and present dogma regarding assessment of the regional lymph nodes and adjuvant therapy for melanoma. Of special interest is radiolymphatic sentinel node mapping of the lymph nodes and adjuvant interferon alfa-2b for thick primary lesions and stage III disease. We also discuss several evolving novel and innovative genetic immunotherapy approaches for patients with stage IV disease.