Interferon-alpha combined with radiotherapy in the treatment of unresectable melanoma

The Florida Melanoma Trial I: A Prospective Multicenter Phase I/II Trial of Postoperative Hypofractionated Adjuvant Radiotherapy with Concurrent Interferon-Alfa-2b in the Treatment of Advanced Stage III Melanoma with Long-Term Toxicity Follow-Up

Radiotherapy (RT) and interferon-alfa-2b (IFN α-2b) have individually been used for adjuvant therapy stage III melanoma with high-risk pathologic features. We hypothesized that concurrent adjuvant RT and IFN α-2b may decrease the risk of regional recurrence following surgery with acceptable toxicity. A prospective multicenter phase I/II study was conducted to evaluate hypofractionated RT with concurrent IFN. Induction IFN α-2b, 20 MU/m2/d, was administered IV ×5 consecutive days every week for 4 weeks. Next, RT 30 Gy in 5 fractions was given with concurrent IFN α-2b, 10 MU/m2 SQ 3 times per week on days alternating with RT. Subsequent maintenance therapy consisted of adjuvant IFN α-2b, 10 MU/m2 SQ 3 times per week to a total of 1 year. To fully evaluate patterns of failure, long-term follow-up was conducted for up to 10 years. A total of 29 consenting patients were enrolled between August 1997 and March 2000. The maximum (worst) grade of acute nonhematologic toxicity during concurrent RT/IFN α-2b (and up to 2 weeks post RT) was grade 3 skin toxicity noted in 2 patients (9%). Late effects were limited. Probability of regional control was 78% (95% CI: 55%–90%) at 12 months. The median follow-up (range) was 80 (51–106) months among ten survivors (43%). The median overall survival was 34.5 months while the median failure-free survival was 19.9 months. Postoperative concurrent hypofractionated RT with IFN α-2b for advanced stage III melanoma appears to be associated with acceptable toxicity and may provide reasonable in-field control in patients at high risk of regional failure.

Future of radiation therapy for malignant melanoma in an era of newer, more effective biological agents

The incidence of melanoma is rising. The primary initial treatment for melanoma continues to be wide local excision of the primary tumor and affected lymph nodes. Exceptions to wide local excision include cases where surgical excision may be cosmetically disfiguring or associated with increased morbidity and mortality. The role of definitive or adjuvant radiotherapy has largely been relegated to palliative measures because melanoma has been viewed as a prototypical radiotherapy-resistant cancer. However, the emerging clinical and radiobiological data summarized here suggests that many types of effective radiation therapy, such as radiosurgery for melanoma brain metastases, plaque brachytherapy for uveal melanoma, intensity modulated radiotherapy for melanoma of the head and neck, and adjuvant radiotherapy for selected high-risk, node-positive patients can improve outcomes. Similarly, although certain chemotherapeutic agents and biologics have shown limited responses, long-term control for unresectable tumors or disseminated metastatic disease has been rather disappointing. Recently, several powerful new biologics and treatment combinations have yielded new hope for this patient group. The recent identification of several clinically linked melanoma gene mutations involved in mitogen-activated protein kinase (MAPK) pathway such as BRAF, NRAS, and cKIT has breathed new life into the drive to develop more effective therapies. Some of these new therapeutic approaches relate to DNA damage repair inhibitors, cellular immune system activation, and pharmacological cell cycle checkpoint manipulation. Others relate to the investigation of more effective targeting and dosing schedules for underutilized therapeutics, such as radiotherapy. This paper summarizes some of these new findings and attempts to give some context to the renaissance in melanoma therapeutics and the potential role for multimodality regimens, which include certain types of radiotherapy as aids to locoregional control in sensitive tissues.

Concurrent adjuvant radiotherapy and interferon-α2b for resected high risk stage III melanoma – a retrospective single centre study

Interferon-alpha2b (IFNalpha2b) is the only form of systemic adjuvant therapy for stage III melanoma with documented survival benefit. Radiotherapy can also be utilized in the adjuvant setting in patients at high risk of nodal basin recurrence. As IFNalpha2b is associated with substantial toxicity, we sought to determine both the systemic and radiation-related toxicities in patients treated with combined adjuvant IFNalpha2b and regional adjuvant radiotherapy delivered in the setting of a single institution. Eighteen consecutive patients who commenced adjuvant IFNalpha2b between November 1997 and August 2002 were analysed retrospectively for toxicities associated with the combination of IFNalpha2b and adjuvant radiotherapy (40-50 Gy in 15-25 fractions) to nodal basins delivered during the maintenance phase of IFNalpha2b therapy (median dose during radiotherapy of 6.5 MU/m three times per week). Seven out of 18 patients who received concurrent radiotherapy and IFNalpha2b displayed grade 3 skin reactions. Severe radiation-induced toxicity was seen in three further patients, one who developed radiation pneumonitis, one who developed severe oral mucositis, and one who developed wound dehiscence that took 10 months to resolve. Non-radiation-related toxicity to IFNalpha2b therapy was typical for this dose and schedule. We conclude that concurrent use of adjuvant radiotherapy and IFNalpha2b may enhance radiation-induced toxicity. However, overall we found concurrent radiation and IFNalpha2b could be safely delivered with appropriate clinical monitoring.