Complete and Durable Response After Radiation Therapy to Primary Tumor Site of a Patient With Metastatic Anorectal Mucosal Melanoma With Oligoprogression on Nivolumab

Multicenter Evaluation of Radiation and Immune Checkpoint Inhibitor Therapy in Mucosal Melanoma and Review of Recent Literature

Purpose

Optimal integration of local therapy and systemic immune therapy for patients with mucosal melanoma (MM) is uncertain. We evaluated treatment patterns and outcomes following radiation therapy (RT) in combination with immune checkpoint inhibition (ICI) in MM.

Methods and Materials

Thirty-seven patients with localized (n = 32, 87%) or node-positive (n = 5, 14%) MM were treated across 4 institutions with RT to the primary tumor with or without oncologic resection (n = 28, 76%) and ICI from 2012 to 2020. Recurrence rates were estimated using cumulative incidence in the presence of the competing risk of death.

Results

Mucosal sites were head/neck (n = 29, 78%), vaginal (n = 7, 19%), and anorectal (n = 1, 3%). Patients received ICI prior to or concurrent with RT (n = 14, 38%), following RT (n = 5, 14%), or at recurrence (n = 18, 49%). The objective response rate for evaluable patients was 31% for ICI as initial treatment (95% CI, 11%-59%) and 19% for ICI at recurrence (95% CI, 4%-46%). Median follow-up was 26 months for living patients; median overall survival (OS) was 54 months (95% CI, 31 months-not reached). Two-year OS was 85%; distant metastasis-free survival 44%. The 2-year cumulative incidence of local recurrence (LR) was 26% (95% CI, 13%-41%). For 9 patients with unresectable disease, 2-year OS was 88% (95% CI, 35%-98%); LR was 25% (95% CI, 3%-58%). For 5 patients with positive nodes at diagnosis, 2-year OS was 100%; LR was 0%.

Conclusions

High rates of local control were achieved with RT with or without oncologic resection and ICI for localized and locally advanced MM. In particular, favorable local control was possible even for patients with unresectable or node-positive disease. Although risk of distant failure remains high, patients with MM may benefit from aggressive local therapy including RT in the setting of immunotherapy treatment.

Cytoreductive Nephrectomy Promoted Abscopal Effect of Camrelizumab Combined With Radiotherapy for Metastatic Renal Cell Carcinoma: A Case Report and Review of the Literature

There is little evidence around Camrelizumab combined with cytoreductive nephrectomy (CN) and radiotherapy (RT) as a treatment option for metastatic renal cell carcinoma (mRCC). The influence of CN on immune responses and the abscopal effect are not well understood. In this paper, we report a case of anti-programmed cell death-1 (PD-1) treated with combined RT once CN reduced the primary tumor burden (TB). This patient also encountered an increased response to targeted radiotherapy after immune resistance. We also observed a macrophage-to-lymphocyte ratio (MLR) peak, which may be correlated with subsequent pseudoprogression after thoracic radiotherapy. Consequently, even with the disease, this patient has remained stable. This peculiar instance suggests there is a need to investigate the underlying mechanisms of CN in promoting the abscopal effect during immunotherapy when combined with RT. It also suggests that there is a need for further investigation into the role of RT in overcoming immune resistance, and the value of MLR in predicting pseudoprogression. We hypothesize that a heavy tumor burden might suppress the abscopal effect, thereby ensuring that CN promotes it. However, radiotherapy may overcome immune resistance during oligoprogression.

Mucosal Melanoma: A Rare Entity and Review of the Literature

Mucosal melanoma is a rare variant of melanoma representing around 1% of total cases of melanoma diagnosed. The usual sites of mucosal involvement are the sino-nasal passages, the oral cavity, and less commonly the upper gastrointestinal (GI) tract. It also has been reported to occur in vulvovaginal and anorectal mucosa. 

We present a rare case of mucosal melanoma that presented as recurrent epistaxis, headache, and sinus pressure. CT maxillofacial imaging revealed a large mass right nasal cavity. This was biopsied by ENT and shown to be mucosal melanoma. This was treated with palliative radiation followed by immunotherapy with nivolumab. 

Along with details of the case, we also discuss current treatment options with a focus on the role of immunotherapy and its efficacy in cases of head and neck mucosal melanoma. Our review of literature supports use of combination immunotherapy (including both nivolumab and ipilimumab) as it shows greater efficacy than either therapy alone. When combined with radiation therapy (RT) the overall response rate is improved and RT induces an abscopal effect; where benefits of RT are also seen at nonirradiated locations. 

In our patient, the use of radiation was essentially palliative as the patient was deemed to not be a surgical candidate. We discuss in our literature review the optimum timing of radiation in relation to definitive surgery or immunotherapy.