Case report: anti-hormonal therapy in the treatment of ductal carcinoma of the parotid gland

BACKGROUND: Ductal carcinomas of the parotid gland are rare, highly aggressive, have a poor prognosis and are histologically similar to Ductal Breast Cancer. We report what we believe to be the first case in literature of metastatic salivary duct carcinoma (SDC) of the parotid gland with objective response to tamoxifen and aromatase inhibitors, achieving a long-term stability of disease with no associated toxicity. CASE PRESENTATION: A 70-year-old female was referred to our institution for treatment of a painless nodular lesion in the scalp, localized in the frontal region of the cranium. A biopsy was taken and tested positive for metastatic ductal carcinoma. On PET CT hypermetabolic nodules were localized in the left parotid gland (11 mm), right parotid gland (10 and 12 mm), submandibular node (11 mm) and left cervical node (10 mm). A salivary ductal carcinoma was considered to be the primary tumor. The patient was subsequently started on tamoxifen, with a complete response from the scalp nodule and left parotid nodule, while the right parotid nodule demonstrated a partial response that maintained stable for 2 years until progression. Anastrazol was chosen as the next line of treatment, achieving 6 more months of stable disease. As a pseudo-adjuvant treatment, surgical resection of the right parotid lesion was performed and helped achieve two years of disease stability. CONCLUSIONS: Estrogen receptor antagonists such as tamoxifen or aromatase inhibitors may represent a target for the establishment of a safe alternative and novel therapy for SDC, however more accurate data obtained from larger studies are required.