Cervical lymph node metastasis is the most important prognostic factor of oral squamous cell carcinoma (OSCC). Therapeutic neck dissection (I-V region) has always been regarded as the standard scheme of neck surgery for patients with cN+ OSCC and however, it has brought obvious side effects, which seriously affects the postoperative quality of life of patients. In addition, excessive neck lymph node dissection will also affect the local immune function of patients to some extent and reduce the body's response to immunotherapy. Lymph node metastasis of primary oral squamous cell carcinoma follows certain rules. Most of the metastatic areas are I-II, and low-level metastasis is very rare. Therefore, more than 90% of patients with cN+ oral squamous cell carcinoma who have undergone Therapeutic neck dissection may have suffered from "excessive dissection of area of IV and V".
Both the long-term clinical experience of surgeons and a large number of recent retrospective studies show that elective neck dissection (I-III region) is safe enough for patients with oral squamous cell carcinoma of cN1 and part of cN2.There is clearly a need therefore for a large randomized trial that will resolve the issue either way once and for all.
Histologically proven T1 or T2 N1 M0( AJCC 8th) squamous call carcinoma of tongue(except base of the tongue ), buccal mucosa, upper and lower gums, hard palate and floor of mouth;
No history of chemotherapy, radiotherapy or targeted therapy,for any reason before
No history of a prior malignancy in head and neck region
No history of a prior malignancy outside head and neck region in the preceding 5 years
failed to obtain the signed written informed consent;
definite distant metastasis or other malignant tumor;
Previous surgical operations for primary tumors or lymph nodes in the head and neck (except biopsy);
previously received radiotherapy for primary tumors or lymph nodes;