Efficacy of combined radiotherapy and anti‐programmed death 1 therapy in acral and mucosal melanoma

Abstract

Some studies showed that clinical response to immune check point inhibitors is lower in acral and mucosal melanoma than in cutaneous melanoma. Although the synergistic effect of radiotherapy (RT) and ipilimumab has been reported in patients with brain metastasis, the efficacy of combined RT and anti‐programmed death 1 (PD‐1) therapy for acral and mucosal melanoma is unclear. The present study aimed to evaluate the efficacy of combined RT and anti‐PD‐1 therapy for acral and mucosal melanoma. We retrospectively analyzed patients with acral or mucosal melanoma who were treated with anti‐PD‐1 and RT at Sapporo Medical University Hospital. In 10 patients (acral, 3; mucosal, 7), the response rate (RR) and the disease control rate (DCR) were 40% and 60%, respectively. As regards mucosal melanoma, four of the seven patients had achieved complete response + partial response, and three had progressive disease (RR = 57.1%). Meanwhile, two of the three patients with acral melanoma had stable disease and one had progressive disease (RR and DCR were 0% and 66.6%, respectively). Except for the patients treated with palliative RT for bone metastasis in the present study, the RR was 50% (4/8 patients), and the DCR was 75% (6/8 patients). Vitiligo developed after RT in five (50%) patients at a median duration of 2 months after RT. The clinical response and the high occurrence of vitiligo suggest that the combination of RT and anti‐PD‐1 therapy could be effective in some patients with mucosal melanoma.

Local and disease control for nasal melanoma treated with radiation and concomitant anti‐programmed death 1 antibody

“…Kato et al. reported the effectiveness of anti‐PD‐1 antibody treatment with concomitant RT for seven patients with mucosal melanoma. Theoretically, RT induces the upregulation of the immune response by increasing T‐cell infiltration into the tumor microenvironment, as well as ICI perhaps having a radiosensitizing effect .…”

“…In comparison with the above-mentioned historical data, in this study, combined treatment with RT and anti-PD-1 antibodies might have achieved superior LC to conventional RT alone whose local control rate was 0-61% 8 and led equivalently favorable LC to carbon ion RT. 10 Kato et al 13 reported the effectiveness of anti-PD-1 antibody treatment with concomitant RT for seven patients with mucosal melanoma. Theoretically, RT induces the upregulation of the immune response by increasing T-cell infiltration into the tumor microenvironment, 14 as well as ICI perhaps having a radiosensitizing effect.…”

Malignant melanoma types and treatment

“…Another study suggested radiotherapy and anti-PD-1 combined treatment was effective in treatment of patients with mucosal melanoma; however, this combination treatment requires further research. [27] Immunotherapy Elimination of tumor cells occurs through a sensitive balance between stimulant pathways and suppressor checkpoints of the immune system. The purpose of immunotherapy is to fundamentally target these checkpoints, inhibit tumor tolerance, and as a result, eliminate tumor cells.…”

“…Aldeseuklin stimulates IL-2 as well as increases cytotoxic abilities of T lymphocytes and NK cells towards cancer cells. [27]…”

Vaginal Mucosal Melanoma: a Complete Remission after Immunotherapy and '0-7-21' Radiotherapy Regimen (24 Gy/3 fractions/21 days)

“…head and neck, genitourinary, etc.). 9,10 The prognosis of melanoma is poor even in case of locally advanced lesions, in fact the 5-years overall survival is about 25% regardless of the therapeutic strategy adopted.…”