This prospective, single-arm, Phase II clinical trial aims to evaluate the efficacy and safety of tislelizumab combined with chemotherapy as neoadjuvant therapy and postoperative adjuvant immunotherapy in patients with skull base-invading head and neck squamous cell carcinoma. The primary objectives are to address the following questions:
* What are the objective response rate and pathological response of tislelizumab combined with chemotherapy as neoadjuvant therapy in patients with skull base-invading head and neck squamous cell carcinoma? * Can neoadjuvant therapy convert unresectable skull base-invading head and neck squamous cell carcinoma into a resectable condition? * Can adjuvant immunotherapy after neoadjuvant therapy prolong patients' recurrence-free survival and overall survival? The researchers will administer neoadjuvant therapy (tislelizumab combined with chemotherapy) and adjuvant immunotherapy to patients with skull base-invading head and neck squamous cell carcinoma and assess the treatment's efficacy and safety.
Participants will:
* Receive neoadjuvant therapy every 3 weeks (tislelizumab 200mg on Day 1, nab-paclitaxel 260mg/m² on Day 1, cisplatin 75mg/m² on Days 1-3) for 3 cycles. * Undergo surgical treatment within 3 weeks after completing neoadjuvant therapy. * Receive (chemo)radiotherapy 4-6 weeks after surgery. * Receive adjuvant immunotherapy (tislelizumab 200mg) every 3 weeks after (chemo)radiotherapy for 8 cycles.
Age 18 to 80 years, regardless of gender;
Histologically confirmed squamous cell carcinoma (including gingiva, buccal mucosa, palate, oropharynx, maxillary sinus, or maxilla/mandible) with radiological evidence of skull base invasion;
Measurable tumor lesions (meeting RECIST v1.1 criteria);
Treatment-naïve primary T4b-stage patients (N any, per AJCC 8th Edition, 2017);
Previous anti-tumor treatments including chemotherapy, radiotherapy, or immunotherapy; Refusal to sign informed consent;
Patients who refuse the study treatment protocol; patients unable to complete treatment as planned; or patients unable to comply with regular follow-up due to psychological, social, familial or geographical reasons;
Patients with known allergies to any study medications;
Patients with poor systemic conditions unfit for treatment: as determined by routine tests (complete blood count, blood biochemistry, ECG, chest X-ray, etc.). Poor systemic conditions include: hemoglobin <60g/L, WBC <3.0×10⁹/L, platelets <80×10⁹/L, or serum creatinine >133μmol/L - such patients may be recommended for conservative treatment;