Management of cN0 low-grade mucoepidermoid carcinomas of salivary glands: Prospective multicentre study of 152 cases of the French Network of Rare Head and Neck Tumors (REFCOR)

Twelve years after: The french national network on rare head and neck tumours (REFCOR)

BACKGROUND

Rare cancers constitute less than 10% of head and neck cancers and lack sufficient evidence for standardized care. The French Rare Head and Neck Cancer Expert Network (REFCOR) as established a national database to collect data on these rare cancers. This study aims to describe patient and tumour characteristics in this database.

METHODS

Prospective data collection was conducted across multiple centers. Survival analyses were performed using Kaplan Meier method and Log Rank test. Odds ratios were used for comparing proportions.

RESULTS

A total of 7208 patients were included over a period of 10 years. The most frequent histologies were: Not Otherwise Specified (NOS) adenocarcinoma 13 %, adenoid cystic carcinoma 12 %, squamous cell carcinoma of rare locations 10 %, mucoepidermoid carcinoma 9 %, intestinal-type adenocarcinoma (8 %). Tumours were located in sinonasal area (38 %); salivary glands (32 %); oral cavity / oropharynx / nasopharynx (16 %); larynx / hypopharynx (3 %); ears (1 %); others (3 %). Tumours were predominantly classified as T4 (23 %), N0 (54 %), and M0 (62 %). Primary treatment approach involved tumour resection (78 %) and / or radiotherapy (63 %). Patients with salivary gland cancers exhibited better 5-year overall survival (OS) rates (p < 0.05), and lower recurrence rates compared to patients with sinonasal, laryngeal/ hypopharyngeal cancers. No significant differences were observed in the other comparisons. Acinar cell carcinoma demonstrated the best OS while mucous melanoma had the poorest prognosis.

CONCLUSION

Melanoma, carcinoma NOS, and sinonasal undifferenciated carcinoma still have poor prognoses. Efforts are being made, including training and guidelines, to expand network coverage (REFCOR, EURACAN), improve data collection and contribute to personalized therapies.

Lymph node surgery for salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for neck dissection in the management of parotid, submandibular or minor salivary gland cancers depending on the clinical situation: i.e., clinical lymph node involvement (cN+) or not (cN0); low or high risk of occult nodal metastasis; diagnosis of malignancy before, during or after surgery.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group which 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

In cN+ salivary gland cancer, ipsilateral neck dissection is recommended. In cN0 salivary gland cancer, ipsilateral neck dissection is recommended, except for tumors at low risk of occult nodal metastasis. If definitive pathology reveals a high risk of occult nodal involvement, additional neck treatment is recommended: ipsilateral neck dissection or elective nodal irradiation.

CONCLUSION

The rate of occult lymph node involvement, and therefore the indication for elective neck dissection, depends primarily on the pathologic grade of the salivary gland cancer.

Post-treatment monitoring of salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the frequency and modality of post-treatment monitoring of primary salivary gland cancer.

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

Clinical monitoring should be adapted to the risk of recurrence: initially every 3 months and progressively spaced out, becoming annual after 5 years. Post-treatment head and neck and chest imaging is recommended at 3 months. Local and regional monitoring can then be carried out yearly or twice yearly with contrast-enhanced head and neck imaging. An annual chest CT scan is recommended for high-grade tumors. For lesions at high risk of late recurrence, very prolonged annual surveillance (up to 15 years) is recommended, including screening for pulmonary metastases.

CONCLUSION

Given the wide range of malignant salivary gland tumors, the modalities and frequency of post-treatment monitoring must be adapted to the expected course of the disease.

[Rare cancers of the head and neck on behalf of the REFCOR, part 1]

Among the 16,000 new cases of malignant tumors of the head and neck diagnosed in France each year, 10% are not conventional squamous cell carcinomas. These so-called rare cancers are distinguished by their presentation and patterns of failure, which is important to recognize in order to offer specific adapted management and maximize the chances of tumor control. These cancers can be rare by their histology, which determines their local invasiveness, and their hematogenous/nodal spread. Their diagnosis can be difficult and often requires comprehensive immunohistochemistry and genomic techniques. Expert pathology review is recommended in the cases of undifferentiated tumors, sarcomas and at the slightest diagnostic doubt. These rare cancers can also be rare by their anatomical location when arising from the paranasal sinuses, salivary glands and ear. Their location requires knowledge of their specific extension routes, and may call for a specific surgical technique (skull base endoscopic sinus surgery, extended total parotidectomy, etc.) and adapted radiotherapy to spare healthy organs surrounding the tumor. This article (part 1) discusses the diagnostic and therapeutic specificities of these rare cancers, and develops the recommendations of the French ENT Cancer Expertise Network (REFCOR) concerning rare epithelial tumors, i.e., salivary tumors, sinonasal tumors, variants of conventional squamous cell carcinomas, neuroendocrine carcinomas, malignant odontogenic tumors, and ear tumors. A second article (part 2) is focused on non-epithelial tumors (sarcomas, mucosal melanomas, lymphomas, tumors of uncertain or undetermined malignancy) and describes the organization and missions of the REFCOR.

Radiotherapy of sinonasal cancers

We present the update of the recommendations of the French society of radiotherapy and oncology on the indications and the technical methods of carrying out radiotherapy of sinonasal cancers. Sinonasal cancers (nasal fossae and sinus) account for 3 to 5% of all cancers of the head and neck. They include carcinomas, mucosal melanomas, sarcomas and lymphomas. The management of sinonasal cancers is multidisciplinary but less standardized than that of squamous cell carcinomas of the upper aerodigestive tract. As such, patients with sinonasal tumors can benefit from the expertise of the French expertise network for rare ENT cancers (Refcor). Knowledge of sinonasal tumour characteristics (histology, grade, risk of lymph node involvement, molecular characterization, type of surgery) is critical to the determination of target volumes. An update of multidisciplinary indications and recommendations for radiotherapy in terms of techniques, target volumes and radiotherapy fractionation of the French society of radiotherapy and oncology (SFRO) was reported in this manuscript.