This is a multi-center, randomized controlled, prospective clinical study.

The early symptoms of hypopharyngeal cancer are often inconspicuous, with approximately 70% of patients clinically diagnosed at an advanced stage. With the emergence of immunotherapy, immune therapies such as PD-1 inhibitors combined with induction chemotherapy have been widely explored in various tumor types. Currently, there is a lack of large-scale real-world studies on the efficacy and safety of treatment options for patients with locally advanced hypopharyngeal cancer who respond well to neoadjuvant therapy. This study aims to employ neoadjuvant chemotherapy combined with immunotherapy for locally advanced hypopharyngeal cancer and explore the effectiveness and safety of different subsequent treatment options for patients assessed as achieving a major partial response (PR ≥50%).

Inclusion Criteria:

1. Willingness to provide written informed consent;
2. Age ≥18 and ≤75 years;
3. Treatment-naïve for malignant disease;
4. Resectable stage III-IVA hypopharyngeal carcinoma with response of PR ≥ 50% after neoadjuvant therapy according to RECIST 1.1 ;
5. ECOG performance status 0-2.

Exclusion Criteria:

1. Pregnancy or breastfeeding status;
2. Hypersensitivity to sintilimab, nab-paclitaxel, or their formulation components;
3. Poorly controlled cardiovascular conditions or other diseases;
4. Active or documented history of autoimmune diseases requiring systemic treatment;
5. Synchronous or metachronous malignancies;
6. Other conditions deemed ineligible for the study by investigators.