The Abscopal Effect in Head-and-Neck Squamous Cell Carcinoma Treated with Radiotherapy and Nivolumab: A Case Report and Literature Review

Abstract

Introduction The abscopal effect is a rarely observed outcome of radiotherapy wherein there is a reduction in metastatic disease burden outside of the targeted treatment area. Likely due to an in situ vaccine effect of radiother­apy, the abscopal effect may be augmented by immunotherapy. This report is the first case of the abscopal effect observed in metastatic head-and-neck squamous cell carcinoma (hnscc) treated with concurrent radiotherapy and single-agent nivolumab.
 Case Description An otherwise healthy 57-year-old man underwent craniofacial resection and adjuvant chemo­radiotherapy for advanced sinonasal squamous cell carcinoma. Distant metastatic disease developed shortly after primary treatment, and immunotherapy in the form of nivolumab was initiated. Subsequent oligometastatic progres­sion despite immunotherapy prompted palliative radiotherapy to a single metastasis due to pending symptomatology. Post-radiotherapy, the abscopal effect was observed with all distant sites of metastatic disease shrinking. Five months following treatment, a sustained reduction in disease burden has been demonstrated.
 Summary We present the first case of the abscopal effect in a patient with metastatic hnscc treated with palliative radiotherapy concurrent with single-agent nivolumab immunotherapy, and only the third case of the abscopal effect in metastatic head-and-neck cancer. Dual treatment with immunotherapy and radiotherapy may be an important treatment option in the future, mediated through the abscopal effect.

Current Therapy for Metastatic Head and Neck Cancer: Evidence, Opportunities, and Challenges

“…37,38 Current management of disease presenting resistance to immunotherapy in the form of oligoprogression remains controversial and is backed by little evidence. Forner et al 39 reported that the addition of stereotactic ablative radiotherapy resulted in a persistent control of the disease in a patient demonstrating oligoprogression, while treated with nivolumab. Ongoing trials evaluating systemic treatment in combination with stereotactic ablative radiotherapy for oligoprogressive HNSCC and oligometastatic HNSCC are needed to better clarify the benefits of treatment and select patients (Table 2).…”

Moving towards the Future of Radio-Immunotherapy: Could We “Tailor” the Abscopal Effect on Head and Neck Cancer Patients?

“…Nivolumab was initiated, even with oligometastatic progression as the best response. Integrating palliative radiotherapy to single metastasis, the abscopal effect was observed with all distant sites of metastatic disease shrinking [73]. Mazzaschi et al described a case of a hypopharyngeal carcinoma with a single bone metastasis, treated with definitive chemoradiotherapy omitting local treatment of the bone lesion, who remained relapse-free for 6 years [74].…”

Combination of radiation therapy-immunotherapy for head and neck cancers: Promises kept?

“…For HNSCC, several cases have already been described. For example, abscopal effect was observed in a patient with metastatic sinonasal squamous cell carcinoma treated with nivolumab 480 mg every 4 weeks after stereotactic body radiation (SBRT) at a dose of 30 Gy in 5 fractions to a single metastasis (28). Another case described an abscopal effect with a complete response of all lesions in a patient with poorly differentiated carcinoma treated with pembrolizumab after SBRT at a dose of 24 Gy in 3 fractions (29).…”