Site of distant metastasis affects the prognosis with recurrent/metastatic head and neck squamous cell carcinoma patients treated with Nivolumab.

BACKGROUND: Nivolumab is approved for the treatment of recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). However, the influence of the site of distant metastasis on the efficacy of immune checkpoint inhibitor in R/M HNSCC remains unclear. We investigated the prognosis of R/M HNSCC patients treated with nivolumab, focusing on the site of distant metastasis. METHODS: We reviewed the data of R/M HNSCC patients treated with nivolumab between April 2017 and June 2020 at Saitama Prefectural Cancer Center. The differences in the prognosis were evaluated according to the site of distant metastasis. RESULTS: Of the 41 patients enrolled, 26 (63.4%) had lung metastasis, 7 (17.1%) had bone metastasis, and 4 (9.8%) had liver metastasis. Ten patients (24.4%) had single-organ distant metastasis (lung metastasis in all cases). Univariate analysis identified lung metastasis alone (single-organ distant metastasis) was associated with a significantly better prognosis [HR0.37 (95% CI) 0.14-0.97 p = 0.04], while liver metastasis was associated with a significantly worse prognosis [HR3.86 (95% CI) 1.26-11.8 p = 0.02]. Multivariate analysis identified lung metastasis alone and liver metastasis as independent prognostic factors. While 7 patients (70%) with lung metastasis alone could be continued on nivolumab treatment or received subsequent chemotherapy, only 1 patient (25%) with liver metastasis received subsequent chemotherapy. CONCLUSION: The site of distant metastasis affects the prognosis of R/M HNSCC patients treated with nivolumab. Lung metastasis alone appears to be associated with a better prognosis, in that it allows easier transition to subsequent chemotherapy, while liver metastasis associates with a worse prognosis.

Denosumab-induced osteonecrosis of external auditory canal.

Denosumab is the world's first human monoclonal antibody for the treatment of osteoporosis and shares an active pathway with bisphosphonates, strongly suppressing osteoclast activities. This is the first case report describing a possible relationship between the development of osteonecrosis of external auditory canal and denosumab administration. We herein report an 81-year-old woman diagnosed with left osteonecrosis of external auditory canal who had a history of denosumab administration. She underwent left radical mastoidectomy due to being refractory to conservative treatment. No major complications or recurrence were observed in the left ear after surgery, but bone erosion in the right ear has continued to progress slowly despite the cessation of denosumab administration. Otolaryngologists should be aware of the association between osteonecrosis of external auditory canal and denosumab administration and consider performing long-term observation even after cessation.