The Current State of Treatment and Future Directions in Cutaneous Malignant Melanoma

Malignant melanoma is the leading cause of death among cutaneous malignancies. While its incidence is increasing, the most recent cancer statistics show a small but clear decrease in mortality rate. This trend reflects the introduction of novel and more effective therapeutic regimens, including the two cornerstones of melanoma therapy: immunotherapies and targeted therapies. Immunotherapies exploit the highly immunogenic nature of melanoma by modulating and priming the patient’s own immune system to attack the tumor. Treatments combining immunotherapies with targeted therapies, which disable the carcinogenic products of mutated cancer cells, have further increased treatment efficacy and durability. Toxicity and resistance, however, remain critical challenges to the field. The present review summarizes past treatments and novel therapeutic interventions and discusses current clinical trials and future directions.

Clinical trials exploring the benefit of immunotherapy and radiation in cancer treatment: A review of the past and a look into the future

Cancer immunotherapy is rapidly redefining the standard of cancer care. The role of radiation therapy in eliciting antitumoral immune response is also being actively investigated in combination with various immunotherapeutic agents to exploit potential synergy between the 2 modalities. In this review, we summarize the rationale and results of past and ongoing clinical trials that combined the use of radiation therapy and immunogenic agents such as vaccines, cytokines, immune checkpoint inhibitors, costimulatory agonists, and myeloid activators.

Stereotactic radiosurgery and immunotherapy for metastatic spinal melanoma

The management of metastatic spinal melanoma involves maximizing local control, preventing recurrence, and minimizing treatment-associated toxicity and spinal cord damage. Additionally, therapeutic measures should promote mechanical stability, facilitate rehabilitation, and promote quality of life. These objectives prove difficult to achieve given melanoma's elusive nature, radioresistant and chemoresistant histology, vascular character, and tendency for rapid and early metastasis. Different therapeutic modalities exist for metastatic spinal melanoma treatment, including resection (definitive, debulking, or stabilization procedures), stereotactic radiosurgery, and immunotherapeutic techniques, but no single treatment modality has proven fully effective. The authors present a conceptual overview and critique of these techniques, assessing their effectiveness, separately and combined, in the treatment of metastatic spinal melanoma. They provide an up-to-date guide for multidisciplinary treatment strategies. Protocols that incorporate specific, goal-defined surgery, immunotherapy, and stereotactic radiosurgery would be beneficial in efforts to maximize local control and minimize toxicity.

Combinations of radiation therapy and immunotherapy for melanoma: a review of clinical outcomes

Radiation therapy has long played a role in the management of melanoma. Recent advances have also demonstrated the efficacy of immunotherapy in the treatment of melanoma. Preclinical data suggest a biologic interaction between radiation therapy and immunotherapy. Several clinical studies corroborate these findings. This review will summarize the outcomes of studies reporting on patients with melanoma treated with a combination of radiation therapy and immunotherapy. Vaccine therapies often use irradiated melanoma cells, and may be enhanced by radiation therapy. The cytokines interferon-α and interleukin-2 have been combined with radiation therapy in several small studies, with some evidence suggesting increased toxicity and/or efficacy. Ipilimumab, a monoclonal antibody which blocks cytotoxic T-lymphocyte antigen-4, has been combined with radiation therapy in several notable case studies and series. Finally, pilot studies of adoptive cell transfer have suggested that radiation therapy may improve the efficacy of treatment. The review will demonstrate that the combination of radiation therapy and immunotherapy has been reported in several notable case studies, series and clinical trials. These clinical results suggest interaction and the need for further study.

Radiotherapy influences local control in patients with desmoplastic melanoma

BACKGROUND

Desmoplastic melanoma may have a high risk of local recurrence after wide excision. The authors hypothesized that adjuvant radiotherapy (RT) would improve local control in patients with desmoplastic melanoma, resulting in at least a 10% absolute decrease in local recurrence rate.

METHODS

A total of 277 patients from 1989 through 2010 who were treated for nonmetastatic desmoplastic melanoma by surgery with or without adjuvant RT were reviewed. Clinicopathologic and treatment variables were assessed with regard to their role in local control.

RESULTS

A total of 113 patients (40.8%) received adjuvant RT. After a median follow-up of 43.1 months, adjuvant RT was found to be independently associated with improved local control on multivariable analysis (hazards ratio, 0.15; 95% confidence interval, 0.06-0.39 [P<.001]). Among 35 patients with positive resection margins, 14% who received RT developed a local recurrence versus 54% who did not (P=.004). In patients with negative resection margins, there was a trend (P=.09) toward improved local control with RT. In patients with negative resection margins and traditionally high-risk features, including a head and neck tumor location, a Breslow depth >4 mm, or a Clark level V tumor, RT was found to significantly improve local control (P< .05). The data from the current study would suggest that patients who would be good candidates for omitting RT included those with negative resection margins, a Breslow depth ≤ 4 mm, and either no perineural invasion present or a non-head and neck tumor location.

CONCLUSIONS

RT for desmoplastic melanoma was independently associated with improved local control. Patients with positive resection margins or deeper tumors appeared to benefit the most from RT, whereas selected low-risk patients can safely omit RT.

Concurrent radiotherapy and ipilimumab immunotherapy for patients with melanoma

Ipilimumab and radiotherapy are commonly used to treat unresectable and metastatic melanoma. Results from preclinical studies and case reports suggest a biologic interaction between these two treatments. To understand the clinical implications of the interaction, we carried out a retrospective study reviewing records of patients treated with ipilimumab and radiotherapy for melanoma at our institution between 2005 and 2011. The review included details of treatment, response, adverse events (AE), and overall survival (OS). Twenty-nine patients underwent 33 courses of non-brain radiotherapy between their first and last dose of ipilimumab. Immune-related AEs (ir-AEs) were observed in 43% of patients receiving ipilimumab at 10 mg/kg and in 22% of patients receiving 3 mg/kg; the frequency of ir-AEs was not significantly different compared with previous studies of ipilimumab alone. Radiotherapy-related AEs were significantly more common in patients receiving higher doses of radiation. Palliation of symptoms was reported by 77% of patients after radiotherapy. Median OS was 9 and 39 months in patients receiving radiotherapy during induction and maintenance with ipilimumab, respectively. In this retrospective study, concurrent ipilimumab and radiotherapy was neither associated with higher than expected rates of AEs nor did it abrogate palliative effects of radiotherapy or survival benefits of ipilimumab. Further studies to prospectively explore the efficacy of this therapeutic combination are warranted.

An update on pegylated IFN-α2b for the adjuvant treatment of melanoma

For patients with localized melanoma, excision of the primary tumor, including lymphadenectomy for nodal metastases, is standard treatment. However, patients with large primary tumors (stage IIB and IIC) or stage III melanoma have a relatively poor prognosis owing to the high risk of recurrence. High-dose IFN-α2b and pegylated IFN-α2b (PEG-IFN-α2b) are the only approved options for adjuvant therapy of stage III melanoma, but the lack of comparative data has led to considerable confusion in choosing between these options. In this article, current evidence regarding the pharmacokinetics, efficacy, safety and tolerability of adjuvant PEG-IFN-α2b in patients with melanoma is reviewed, with frequent reference to and comparisons with data using IFN-α2b. Particular focus is given to the pharmacokinetic differences between IFN-α2b and PEG-IFN-α2b and their implications for the treatment of high-risk patients. In addition, emerging evidence suggests that PEG-IFN-α2b therapy may provide clinically significant overall survival benefit for selected high-risk patients.

Dendritic cell immunotherapy in soft tissue sarcoma

Soft tissue sarcomas represent a rare but diverse family of tumors affecting patients of all ages. Conventional chemotherapy rarely eradicates metastatic disease and newer targeted agents are successful in only very specific histologic subgroups. Therefore, scientists and clinicians are investigating immunotherapy techniques, primarily involving cellular immunity focused on the T-cell response to tumor antigens. In both animal models and human sarcoma trials, dendritic cells have been shown to induce an effective antitumor immune response. Radiotherapy, particularly when delivered in a hypofractionated manner prior to sarcoma excision, may potentiate the function of the dendritic cells through the induction of apoptosis. The synergistic effect may carry over to other cancer types and warrants further multidisciplinary investigation.