A clinicopathological study of parotid carcinoma: 18-year review of 171 patients at a single institution.

BACKGROUND: This study investigated the clinical outcomes of patients with parotid carcinoma at a single institution during an 18-year period, with the focus on diagnosis, treatment, and survival. METHODS: The subjects were 171 patients with parotid carcinoma treated at our department during the 18-year period from September 1999 to August 2017. There were 19 patients in stage I, 65 patients in stage II, 22 patients in stage III, and 65 patients in stage IV. The symptoms, preoperative diagnosis, node metastasis, survival rate, prognostic factors, and immunohistological findings were investigated. RESULTS: Preoperative diagnosis of the histological grade by fine-needle aspiration cytology was only possible in 34% of the patients, while the histological grade was correctly determined by frozen section biopsy in 72%. The overall frequency of lymph node metastasis was 29%, with 59% in patients with high-grade carcinoma and only 6% in those with low-/intermediate-grade tumors. The disease-specific 5-year survival rate was 100% for patients in stage I, 95.2% in stage II, 70.4% in stage III, and 45.1% in stage IV. Multivariate analysis showed that the pathological grade was the most important prognostic factor. Immunohistological investigation showed patients with HER-2 or androgen receptor-positive tumors had a significantly worse prognosis. CONCLUSIONS: Although a high-grade tumor is the most important prognostic factor, preoperative diagnosis of the grade was not always accurate. Since advanced cancer has a poor prognosis with a limited response to surgery and radiation therapy, development of new treatment strategies, such as molecular-targeting therapies directed against HER-2 and AR, is required.

Characteristic Formation of Hyaluronan-Cartilage Link Protein-Proteoglycan Complex in Salivary Gland Tumors.

Hyaluronan (HA) and its binding molecules, cartilage link protein (LP) and proteoglycan (PG), are structural components of the hydrated extracellular matrix. Because these molecules play important roles in the tumor microenvironment, we examined the distribution of HA, LP, versican, and aggrecan in salivary gland tumors using histochemical and immunohistochemical methods, including double staining. LP was present in pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) tissues, and aggrecan was absent in the malignant tumors that we investigated. LP colocalized with both HA and aggrecan in the chondromyxoid matrix of PA, suggesting the presence of a HA-LP-aggrecan complex. Furthermore, the HA-LP-versican complex could be observed in the pseudocystic space of the cribriform structures in ACC. The characteristic HA-LP-PG complex in PA and ACC might play a role in the behavior of tumors, and immunohistochemical analysis of these molecules could represent a diagnostic adjunct for salivary gland tumors.