Clinicopathological Features And Risk Factors For Skip Lymph Node Metastasis In Papillary Thyroid Cancer

Objective:Analyzing the clinicopathological characteristics and risk factors for the lymph node skip metastasis in thyroid papillary cancer,and exploring its influence on the prognosis of patients with thyroid papillary cancer,in order to provide reference for clinical surgical decision,and reduce the recurrence rate and the reoperation rate of thyroid cancer,and prolong the disease-free survival rate of thyroid cancer patients.Method:A total of 952 papillary thyroid cancer patients who underwent thyroid surgery in our department from October 2010 to February 2021 and met the inclusion criteria were selected.The clinical and pathological data of the included patients were collected and sorted out,and the data were statistically analyzed by SPSS26.0software.The test standard was α=0.05,and the difference was considered statistically significant when p< 0.05 on both sides.Results:1.A total of 42 of 952 patients with papillary thyroid carcinoma had lymph node skip metastasis.Male: female 10:32（1:3）,with an average of 44.67±11.68 years old.The largest lesion was 4cm in diameter.Membranous invasion in 37 cases（88.10%）;nerve invasion in 3 cases（7.14%）;vascular invasion in 4 cases（9.52%）;there were 14 cases（33.33%）of extradglandular invasion,including 5 cases（11.90%）of muscle invasion and 9 cases（21.43%）of adipose tissue invasion.Among them,4cases jumped to the contralateral central region,33 cases jumped to the ipsilateral lateral cervical region,3 cases jumped to the contralateral central region and ipsilateral lateral cervical region,2 cases jumped to bilateral lateral cervical region.There were 19 cases occurring lateral cervical lymph node metastasis in single zone: 3cases in zone II,10 cases in zone III,and 6 cases in zone IV.12（one patients had bilateral lateral cervical metastasis and another patients had a right single zone and two zone in left lateral cervical lymph node metastasis）patients had metastases in two zones: 7 in zone II+III,2 in zone II+IV,and 4 in zone III+IV.There were 8 patients with three regional metastases II+III+IV.2.Univariate analysis showed that there was a correlation between the occurrence of single lesion,unilateral lesion,large lesion maximum diameter（cut-off value 0.95 cm,sensitivity 0.667,specificity 0.657）,lesion in the upper lobe of the glandular,lesion invasion of the nerve,lesion invasion of the extra-glandular and skip metastasis（p<0.05）.Multivariate analysis showed that the lesion was located in the upper part of the glandular lobe（OR=0.271,95%CI 0.137-0.535,p<0.001）、single lesion（OR=0.277,95%CI 0.139-0.554,p<0.001）and nerve invasion（OR=0.244,95%CI 0.061-0.970,p=0.045）were independent risk factors for skip metastasis.The maximum diameter of lesion ≤1cm（OR=2.410,95%CI 1.415-5.310,p=0.003）was a protective factor for skip metastasis.3.There was no statistical difference in the number and positive rate of lymph node dissection in each area of lateral neck between the skip metastasis group and the non-skip metastasis group.In the group of patients with lateral cervical node skip metastasis,the incidence of lateral cervical single region metastasis was higher than that of two or three regions,and the incidence of single region metastasis was as follows: III（26.32%）> IV（15.79%）> II（7.89%）.4.The recurrence rate and recurrence time of papillary thyroid carcinoma patients in the skip lymph node metastasis group were not statistically different from those in the non-skip lymph node metastasis group（p> 0.05）,but the number of days in hospital was significantly longer than that in the non-skip lymph node metastasis group.Conclusion:1.The incidence of lymph node skip metastasis in patients with papillary thyroid cancer was 4.41%,and the probability of skipping to the ipsilateral cervical region was significantly higher than that to the contralateral central region,with a ratio of8:1.2.The location of the lesion in the upper lobe of the gland,the lesion invading the nerve,the single lesion and the maximum diameter of the lesion > 1cm were independent risk factors for the occurrence of lymph node skip metastasis of papillary thyroid cancer.3.In the lateral cervical lymph node metastasis in single region,zone III was most frequently involved,so the zone III dissection should be paid special attention to during "lateral cervical lymph node dissection".4.The recurrence rate and recurrence time were not affected by skipping metastasis.