Anorectal mucosal melanoma

Anorectal melanoma is an uncommon and aggressive mucosal melanocytic malignancy. Due to its rarity, the pre-operative diagnosis remains difficult. The first symptoms are non-specific such as anal bleeding, anal mass or pain. Although anorectal melanoma carries a poor prognosis; optimal therapeutics strategies are unclear. Surgical resection remains the mainstay of treatment. The optimal surgical procedure for primary tumours is controversial and can vary from wide local excision or endoscopic mucosal resection (EMR) to an abdomino-perineal resection. A high degree of uncertainly exists regarding the benefit of radiation therapy or chemotherapy. The treatment of advanced melanoma is evolving rapidly with better understanding of the disease biology and immunology. Considerable effort has been devoted to the identification of molecular determinants of response to target therapies and immunotherapy.

Chemotherapy in the management of advanced cutaneous malignant melanoma

The recent past has witnessed unprecedented clinical progress in the treatment of advanced malignant melanoma through targeting of mutant BRAF in approximately 50% of patients and immune check point blockade in all patients. As has been well documented, responses to targeted therapy are of limited duration, and rates of clinical benefit to immunotherapy are modest. Given these factors, palliation of patients with chemotherapy remains an essential aspect of melanoma oncology. Many chemotherapeutics (and combinations with other agents, such as immunotherapy) have been evaluated in melanoma, although no chemotherapy regimen has been documented to provide an overall survival benefit in a prospective, randomized, well-controlled phase III study. We provide an overview of the development of the most common chemotherapy regimens for melanoma, discuss the clinical trial evidence supporting and contrasting them, and highlight appropriate clinical situations in which they might be used. We also discuss the future of chemotherapy for melanoma, noting the potential for combinations of chemotherapy with either targeted or immunotherapeutic agents.

Targeting angiogenesis in melanoma: prospects for the future

Angiogenesis has been identified as a relevant target for melanoma experimental therapeutics, based on preclinical and clinical studies. A variety of angiogenesis inhibitors are currently being tested in both metastatic and adjuvant melanoma clinical trials. To date, the most promising evidence of benefit is based on a statistically nonsignificant trend in survival gain reported in a randomized phase II trial combining bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor, with cytotoxic chemotherapy. Larger phase III studies are required to determine the true extent of clinical benefit with this class of agents. Key to these clinical trials is the need to include translational endpoints, since correlation of biological and clinical data will provide the opportunity to identify biomarkers predictive of treatment response. These biological studies will also aid our, as yet, poor understanding of the mechanism of action of angiogenesis inhibitors, as well as drug-related side effects. Finally, if these trials show meaningful clinical benefit, then careful consideration will need to be given when designing second-generation trials, in the light of novel gene-directed therapies currently showing promise in melanoma.

Bevacizumab and everolimus in the treatment of patients with metastatic melanoma: a phase 2 trial of the Sarah Cannon Oncology Research Consortium

BACKGROUND

In this phase 2 study, the activity and tolerability of the combination of bevacizumab, an inhibitor of angiogenesis, and everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), was evaluated in the treatment of patients with metastatic melanoma.

METHODS

Patients with metastatic melanoma who had received up to 2 previous systemic regimens (chemotherapy and/or immunotherapy) were eligible. Previous treatment with angiogenesis or mTOR inhibitors was not allowed. All patients received bevacizumab at a dose of 15 mg/kg intravenously every 21 days and everolimus at a dose of 10 mg orally daily. Patients were re-evaluated every 6 weeks; those with an objective response or stable disease (according to Response Evaluation Criteria in Solid Tumors [RECIST]) continued therapy until tumor progression or unacceptable toxicity occurred.

RESULTS

Fifty-seven patients with metastatic melanoma received a median of 4 treatment cycles (range, 1-14+ cycles). Seven patients (12%) achieved major responses, whereas 33 patients (58%) were found to have stable disease at the time of first evaluation. The median progression-free and overall survivals were 4 months and 8.6 months, respectively. Approximately 43% of patients were alive after 12 months of follow-up. The treatment regimen was well tolerated by the majority of patients.

CONCLUSIONS

The combination of bevacizumab and everolimus was found to have moderate activity and was well tolerated in the treatment of patients with metastatic melanoma. Further exploration of agents with these mechanisms of action is indicated, perhaps in combination with inhibitors of the mitogen-activated protein kinase (MAPK) pathway.

Angiogenesis in cutaneous malignant melanoma and potential therapeutic strategies

Metastatic melanoma (MM) carries a dismal prognosis, as it is largely resistant to conventional cytotoxic chemotherapy, biochemotherapy and immunotherapy. There is, therefore, a pressing need to identify new, effective treatments to improve outcomes from MM. Innovative approaches in oncology drug development include anti-angiogenic strategies, in the form of monoclonal antibodies and small-molecule kinase inhibitors. In this review we aim to present current concepts and controversies surrounding the role of angiogenesis and anti-angiogenic therapies in MM, alluding to other tumor types in which increasing knowledge may supply avenues for future directions in melanoma research and management. An overview of angiogenesis and its importance in melanoma progression is presented, highlighting the key molecules that represent potential therapeutic targets. The results of using anti-angiogenic strategies in preclinical and clinical trials are discussed and future perspectives for anti-angiogenic therapies in MM are considered.