Diagnosis And Treatments Of Patients Diagnosed As Cervical Lymph Node Metastasis From Unknown Primary Site

Objective Cervical lymph node metastasis from unknown primary site(CUP)refers to cervical lymph node metastasis without primary lesion found,which accounts for 1-4% of head and neck tumors,and squamous cell carcinoma is the most common pathological type.Due to the low incidence of CUP,there are difficulties in detecting primary tumors now,and most of the studies are retrospective analysis of small samples and lack of prospective randomized clinical trials.Although the proportion of unidentified primary lesions in cervical metastases has decreased with the advancement of imaging techniques,CUP remains a troublesome disease in head and neck tumors.And the NCCN guideline still fail to propose the best diagnostic treatment means,and the selection of the diagnosis and treatments has always been difficult points clinically.The purpose of this study was to investigate the clinicopathological features of CUP and the characteristics of the primary lesions.The effectiveness and specificity of 18-fluorodeoxyglucose positron emission tomography(PET/CT)on the basis of traditional imaging examination was performed to detect primary lesions.Features on prognosis,and the survival of different treatments were compared,as well as the application value of induction chemotherapy in the later stage CUP.The aim of this study was to provide reference for clinical diagnosis and treatments,to improve the prognosis,and provide ideas for individualized treatments.Methods 1.Retrospective analysis of 526 cases of CUP in Tianjin Medical University Cancer Institute & Hospital with clinical pathological features and treatments.Patients who had not found the primary tumor during the follow-up were assigned to the primary unidentified group.The primary diagnosis group included patients with primary tumor detected.The clinical manifestations of the primary diagnosis group and the primary unidentified group were analyzed.The sensitivity and specificity of PET / CT and traditional imaging to detect primary lesions were examined.2.The prognosis of 365 patients in the original unidentified group who had not found primary lesions during follow-up were collected,including overall survival(OS)and progression-free survival(PFS).The clinicopatholocal features,factors affecting local recurrence,distant metastasis and prognosis,as well as effects of treatments on OS and PFS were analyzed.Statistical analysis was performed using the SPSS 23.0 software system through Kaplan-Meyer analysis,chi-square test,Kaplan-meier method and Cox regression model.Results 1.526 patients met the inclusion criteria,and men were more common.The median age was 57 years old.Primary lesions of 161(30.6%)patients were found,and patients aged ?60 years(56.6%)had more probability to detect primary lesions than that of patients with age > 60 years(28.1%).Compared with traditional imaging,PET/CT had higher sensitivity and specificity to detecte the primary lesion.2.The overall 2-year and 5-year survival rates of the 365 patients with unidentified patients were 77.0% and 33.4%,respectively,with a median survival of 45 months.Gender,age,pathological type,lymph node stage and cervical lymph node dissection are important factors influencing local recurrence.The pathological type is adenocarcinoma,the degree of differentiation is poor,and patients with later stage of lymph node suggest that the probability of distant metastasis were higher.In the univariate analysis,age,lymph node stage,treatments,and distant metastasis were statistically associated with OS and PFS.And treatment,local recurrence,and distant metastasis were independent prognostic factors in multivariate analysis.Patients with N1-N2 a stage had a better prognosis with surgery or radiotherapy alone;patients with later lymph node stage(N2b-N3)benefited from induction chemotherapy or postoperative radiotherapy.Conclusion 1.CUP patients were more common in men,lymph node metastasis were mostly located in the upper neck,the squamous cell carcinoma was more common.The detection rate of primary lymph nodes in patients with ?60 years old was higher than that in patients with age >60 years old.PET/CT examination was important for the detection of primary tumors.2.Prognosis of patients were related to age,lymph node stage,treatments,local recurrence and distant metastasis.Different lymph node stage using different treatments: A single surgery or radiotherapy for patients with N1-N2 a had good prognosis.For N2B-N3 patients,induction chemotherapy or postoperative radiotherapy had benefits for these patients.