The authors present the guidelines of the REFCOR French expert network for rare head-and-neck cancers for the management of sinonasal squamous cell carcinoma (SNSCC).

A multidisciplinary working group conducted a literature review on the topic. The formalized expert consensus methodology was used to draw up the guidelines. Guidelines were classified according to the degree of agreement among the members of the working group.

Strong agreement: due to the risk of malignant transformation, resection is recommended for sinonasal inverted papilloma; facial CT and MRI are recommended for local extension assessment. Relative agreement: for poorly differentiated or undifferentiated SNSCC, expert pathological review is recommended; for lymph node and distant metastasis assessment, cervical and thoraco-abdominal-pelvic CT or 18-FDG PET scan is recommended; for the primary tumor, surgical resection with clear margins followed by adjuvant radiotherapy is recommended; prophylactic radiotherapy is recommended for N0 patients for at least levels 1b and 2 and retropharyngeal lymph nodes; in T1 lesion operated on with clear margins, surgery alone should be discussed in a tumor board; radiotherapy or chemotherapy alone are not recommended for curative treatment of operable SNSCC; after treatment, it is recommended that patients be monitored for at least 5 years: 4 times a year for the first 2 years, 3 times a year for the 3rd year, then 2 times a year until the 5th year. Disagreement: systematic induction chemotherapy before surgery is not recommended; in case of orbital extension, induction chemotherapy followed by concomitant chemoradiotherapy should be discussed.