Stable disease under checkpoint inhibition in pulmonary metastatic salivary duct carcinoma.

Salivary duct carcinomas of the parotid gland are highly malignant and rare tumors. Although they are an effective treatment option for many tumor entities, there is little data about their effectiveness in salivary duct carcinoma. A 65-year-old man presented alio loco with a preauricular mass that had been present for 2 months. He underwent a total parotidectomy and ipsilateral selective neck dissection of levels I-IV. After histopathologic evaluation for SCC metastasis to the parotid gland with unknown primarius DD primary SCC of the parotid gland, he presented in domo for adjuvant radiochemotherapy with cisplatin by our radiation clinic. After restaging, the patient presented to our Head and Neck Tumor Board with multiple size-progressive pulmonary round lesions. He then underwent wedge resection of the right middle lobe for histologic confirmation of the round foci. On synopsis with the new pulmonary specimens and the preliminary material from alio loco, he was now found to have metastatic salivary duct carcinoma. With positive HER2 expression status, off label therapy with trastuzumab/docetaxel was initially initiated. This initially resulted in a mixed response with partly regressed and partly progressive pulmonary foci, but during the 15 cycles a new consolidation appeared in the right upper lobe and the majority of pulmonary filiae were clearly progressive. Subsequently, with negative PDL-1 status, a trial of therapy with nivolumab was initiated. Under this treatment (30 cycles so far), the patient shows stable disease. The therapy is well tolerated with almost no side effects. This case shows that checkpoint inhibitors can be a promising therapeutic option in metastatic salivary gland tumors.

Publication History

Article published online:
12 May 2023