The treatment guideline for locally advanced resectable oral squamous cell carcinoma (LAROSCC) is surgery + postoperative radiotherapy/chemoradiotherapy. Though the treatment is intensive with serious harm to quality of life, the survival of patients is poor. Neoadjuvant therapy has been evaluated in a number of clinical trials for LAROSCC, but failed to directly improve the overall survival. On the other hand, de-escalation of treatment followed by neoadjuvant is also been explored with some promising results. This study is to retrospectively include patients with LAROSCC who received neoadjuvant therapy and surgery. Survival between patients in two cohorts (cohort 1: received postoperative radiotherapy, cohort 2: received no postoperative radiotherapy) are to be compared.