头颈部鳞癌患者发生第二原发癌的危险性较大,其发生率在7％～14％。一部分病例可在初诊检查时发现,但同时病变(synchronous lesion)(指发生在患者初诊后6月内的病变)也可包括来自头颈部原发灶的远处转移癌。同时肿瘤的发生率在1％～3％,最高可达16％,这类病变的出现可影响患者的预后,还可改变治疗方案。多数单位依据胸部X线和上消化—呼吸道内 Patients with head and neck squamous cell carcinoma have a higher risk of developing second primary cancer, with an incidence of 7% to 14%. Some cases may be found at the time of the initial examination, but synchronous lesions (referring to lesions occurring within 6 months of the patient’s initial visit) may also include distant metastatic cancers from the primary site of the head and neck. At the same time, the incidence of tumors ranges from 1% to 3%, with a maximum of 16%. The occurrence of such lesions can affect the prognosis of patients and can also change the treatment plan. Most units are based on chest X-rays and upper digestive-respiratory tracts