Clinical Outcome of Minor Salivary Gland Cancers in the Oral Cavity: A Comparative Analysis With Squamous Cell Carcinomas of the Oral Cavity

Surgery of sublingual and minor salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications and modalities for resection in the management of primary sublingual and minor salivary gland cancer, and the specific features of each primary location.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group who drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Histological evidence (submucosal biopsy) is recommended before surgical treatment of minor salivary gland carcinoma. Surgical treatment is recommended, with optimal oncologic margins, adapted to anatomical factors, histologic type and grade and functional consequences, with reconstruction if necessary.

CONCLUSION

Treatment of primary minor salivary and sublingual gland cancer is surgical, with wide resection margins. The modalities of resection and reconstruction are highly dependent on tumor location, extension and histologic type.

Pre-treatment quality of life in patients with salivary gland cancer in comparison with those of head and neck cancer patients

INTRODUCTION

Salivary gland cancer (SGC) is a rare malignant tumor arising from the salivary glands, with a variety of clinical and biological behaviors different from head and neck cancer (HNC). Because of the rarity of SGC, there are limited data on pre-treatment quality of life (QoL). Therefore, we evaluated the pre-treatment QoL in SGC patients by stage and compared it with that of HNC patients.

METHODS

From a prospective registry of HNC patients (2016-2020), we selected 225 patients with SGC, and 912 patients with oral cavity (OC) and oropharyngeal cancer (OPC) who were diagnosed in the same period as the HNC control group. The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) and HNC-Specific Module (H&N35) were used to assess QoL.

RESULTS

SGC patients had a statistically better baseline QoL (69.8 vs. 64.0), emotional (82.1 vs. 78.8), cognitive (92.0 vs. 88.7), and social function (86.3 vs. 80.5), and fewer symptoms than HNC patients. The estimated average QoL differences between SGC patient diagnosed at stages I and IV was -12.9. Especially, advanced-stage of tumors was associated with much lower role functioning and emotional functioning scores in SGC patients, compared to those in HNC patients, among females and of younger age.

DISCUSSION

Although the overall QoL score was higher in SGC patients than in HNC patients, specific domains were significantly affected in SGC patients according to the tumor stage. Females and those of younger age were more affected by severity of disease in SGC.

STUDY REGISTRATION

ClinicalTrials.gov Identifier NCT02546895.

Carnosic Acid Suppresses the Development of Oral Squamous Cell Carcinoma via Mitochondrial-Mediated Apoptosis

Oral squamous cell carcinoma (OSCC) predominantly consists of squamous cells and is the tumor with the highest incidence of the head and neck. Carnosic acid (CA), a natural monomer drug obtained from rosemary and salvia, shows various pharmacological effects, including of tumor development. This study aimed to assess for an effect of CA on the development of OSCC and the underlying mechanisms. In CAL27 and SCC9 cells, CA inhibited cell proliferation and migration, increased intracellular levels of reactive oxygen species (ROS) and Ca²⁺, decreased the mitochondrial membrane potential (MMP), and promoted apoptosis. In CAL27- and SCC9-xenotransplanted BALB/c nude mice, CA inhibited the tumor growth without affecting the body weight and tissue morphology. CA upregulated Bax, Bad, cleaved Caspase-3 and -9 levels, and the cleaved PARP1/PARP1 ratio but downregulated Bcl-2 in CA-treated OSCC cells and OSCC cells-xenotransplanted BALB/c nude mice. These results indicate that CA suppresses OSCC at least via the mitochondrial apoptotic pathway and offers this natural compound as a potential therapeutic against OSCC.

Diagnosis and management of malignant sublingual gland tumors: a narrative review

OBJECTIVE

In this article we review the literature on the malignant sublingual gland tumors from a surgical perspective.

BACKGROUND

Sublingual gland tumors occur with a very low incidence and most are malignant tumors. The extent of treatment, clinical outcomes and prognosis of malignant sublingual gland tumors have not been well defined, due to the rarity of this disease.

METHODS

A database search using Web of Science (https://webofknowledge.com/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/) was conducted. The following keywords were used in the search: "sublingual gland tumor", AND "malignancy".

CONCLUSIONS

Although the sublingual glands are among the major salivary glands, they share common anatomical characteristics with minor salivary gland tumors. Therefore, the tumors from the sublingual gland may have different clinical behaviors from the other major salivary gland tumors. The sublingual glands are small without a true surrounding capsule of the glands; the extra-parenchymal extension is very common in sublingual gland tumors. Furthermore, the sublingual glands are located in close proximity to the lingual nerve, the submandibular gland-duct system and the mandible. Thus, the surgical approach to the malignant sublingual gland tumor should include the adequate management of neighboring structures. In addition, adjuvant radiation therapy provides a survival benefit for patients with malignant sublingual gland tumors, which have adverse features. This article summarizes the clinical characteristics and unique features of malignant sublingual gland tumors based on previous reports, and provides clinical information regarding the sublingual gland tumors to increase awareness of primary physicians as well as patients.

Prognostic analysis and nomogram establishment in patients with mucoepidermoid carcinoma of the tongue: a population-based study using the SEER database

OBJECTIVES

To describe the clinicopathological characteristics and determinants of survival of patients with mucoepidermoid carcinoma (MEC) of the tongue.

METHOD

Retrospective population-based study was conducted using the data of patients diagnosed with MEC of the tongue from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2016.

RESULTS

A total of 200 cases of MEC of the tongue were identified. The cohort was composed of 56.5% females. The mean age at diagnosis was 58.8 years. The base of the tongue was the most common primary site (72.5%). Most cases (80.9%) presented with T1 and T2. Lymph node metastases was present in 40.9% of cases, while distant metastases only observed in 2.2% of cases. Overall survival (OS) at 2, 5, and 10 years was 80.2%, 69.8%, and 52.4%, respectively. 77.5 percent of cases (155/200) underwent surgery, and 66 cases received both surgery and radiation therapy. Patients with post-operative radiation had much longer disease-specific survival (DSS). Advanced T stage, distant metastasis contributed independently to shorter OS, while the use of surgery is an independently favorable prognostic factor for OS. In addition, an OS-specific nomogram was established, and the C-index for OS prediction was 0.74 (95% CI 0.67-0.81).

CONCLUSION

This rare malignancy is associated with a generally favorable prognosis, and T stage, distant metastasis as well as surgical therapy are independent predictors of OS.

Primary acinic cell carcinoma of mandible, report of a case and literature review

Introduction and importance

Acinic cell carcinoma (ACC) is a rare low-grade salivary gland malignancy that accounts for approximately 17% of all salivary gland malignancies. The most common site affected by ACC is the parotid gland followed by the submandibular glands, minor salivary glands, and sublingual glands. Also, it could hardly be observed in unusual sites such as the jaw bones.

Case presentation

This case is an example of a central acinic cell carcinoma in a 73-year-old man who came up with a painless gradual swelling for 15 months. Based on clinico-radio-pathologic findings, the diagnosis of a solid variant Intraosseous Acinic Cell Carcinoma was established. Subsequently, the patient underwent hemimandibulectomy and modified radical neck dissection, followed by postoperative radiotherapy. Within a six-month follow-up period, no evidence of residual tumor was found.

Clinical discussion

Central salivary gland carcinoma is a rare entity and intraosseous ACC is more scarcely observed. Based on our findings, a total of 17 cases of primary intraosseous ACC have been reported so far. Etiology and clinical presentations of this tumor are still vague due to its rarity.

Conclusion

Dentists and oral surgeons must be aware of such a rare malignant lesion when encountering a radiolucent lesion within the jaws. The early diagnosis and a complete surgical excision to achieve tumor-free surgical margins and a long-term follow-up could result in significantly improved survival rates.

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ACCs are a type of uncommon salivary gland tumors and the intra-osseous counterparts are extremely rare.

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Due to clinical and radiologic similarities to benign tumors, histopathologic and IHC findings should also be considered.

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Primary surgical design should be wide enough and en bloc resection should be suggested.

Analysis of local invasion and regional spread in malignant sublingual gland tumour: Implications for surgical planning

Malignant tumours arising from the sublingual glands are very rare, and the extent and frequency of local invasion or regional spread in malignant sublingual gland tumour (MSLT) has not been fully studied due to the disease rarity. To provide comprehensive features of local and regional spread of MSLT, we reviewed 20 surgical cases for detailed pathological analyses among 26 cases diagnosed as having primary MSLT. Adenoid cystic carcinoma (ACC) was the most common pathological subtype, followed by mucoepidermoid carcinoma. Disease-free and overall survivals at 5 years were 76.1 % and 77.7 %, respectively. High-grade malignant tumours and grade 2-3 ACC accounted for 41.7 % and 85.7 %. Clinical and pathological extraparenchymal extensions were found in 34.6 % and 80.0 %, respectively. Tumour invasion to the lingual nerve and submandibular gland/ductal system were also detected in 40.0 % and 28.6 %. The incidences of lingual nerve invasion in ACC and ACC ≥4 cm were 30.8 % and 42.9 %. Regional nodal involvement occurred in seven of 26 cases, and all metastatic lymph nodes were found in neck levels Ib and IIa. In summary, a significant portion of MSLT cases consisted of high-grade tumours and grade 2-3 ACC; therefore local invasion into adjacent structures should be cautiously evaluated in cases of MSLT.

The Periphery of Salivary Gland Carcinoma Tumors Reveals a PD-L1/PD-1 Biomarker Niche for the Evaluation of Disease Severity and Tumor-Immune System Interplay

The treatment options for patients with advanced salivary gland cancers (SGCs) are limited. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, the response to ICI immunotherapy is largely driven by the immune cell signatures within the tumor tissue and the para-tumoral tissue compartments. To date, there are no data on the expression of programed cell death protein-1/programed cell death protein-ligand 1 (PD-1/PD-L1) in SGC, which may enable the implementation of ICI immunotherapy for this disease. Thus, we performed an immunohistochemical analysis of PD-1 and PD-L1 expression in tumor cells and tumor-infiltrating immune cells (TIICs) in the tumor center and periphery of 62 SGC patients. The tumor periphery showed significantly higher expression of PD-L1 in tumor cells than in TIICs. Moreover, peripheral TIICs had significantly higher PD-1 expression than peripheral tumor cells. PD-1-positive tumor cells were detected exclusively in the tumor center of high-grade tumors, and most importantly, the presence of lymph node (LN) metastases and primary tumor stage significantly correlated with the presence of PD-L1-positive tumor cells in the tumor periphery. The PD-1/PD-L1 molecular signatures in SGC are clustered predominantly in the tumor periphery, reflect disease severity, and may predict the response to ICI immunotherapy in SGC patients.