Introduction: Maxillary sinus cancer is a relatively rare head and neck malignancy. Despite advances in treatment, it remains a therapeutic challenge. This study aimed to evaluate treatment outcomes in maxillary sinus cancer patients depending on the timing of radiotherapy initiation after surgery.

Material and methods: A retrospective analysis of 91 patients treated for maxillary sinus cancer was performed. Depending on the treatment modality, patients were divided into 3 groups: I — surgery + adjuvant radiotherapy (n = 77), II — palliative radiotherapy (n = 10), and III — radical radiotherapy only (n = 4). Overall survival (OS) was assessed.

Results: The longest median OS (30.6 months) was observed in group I. It was demonstrated that the timing of radiotherapy initiation after surgery is crucial — with 3–4 weeks interval OS was 75 and 60.4 months, respectively. Patients with treatment failure in the form of distant metastases had shorter median OS (4.4 months) compared to those with local recurrence (10.9 months).

Conclusions: Combined treatment with surgery + adjuvant radiotherapy provides the best results. Postoperative radiotherapy should be initiated no later than 4 weeks after surgery, which significantly prolongs median overall survival. Commencing radiotherapy within 3–4 weeks after surgery markedly improves the prognosis. Patients who developed local recurrence have better prognosis compared to those with distant metastases.