A clinical study of range of central lymph node dissection for papillary thyroid carcinoma in cN0 T1/T2

Abstract:

Objective：To investigate the reasonable range of central lymph node（CLN） dissection for papillary thyroid carcinoma （PTC） in cN0 T1/T2 by analyzing the metastatic pattern of PTC in cN0 T1/T2. Methods：A total of 532 patients with PTC in cN0 T1/T2 who were consecutively admitted to the same treatment group in Department of Thyroid Surgery，The First Affiliated Hospital of Kunming Medical University，from October 2013 to September 2016 were enrolled in this study. All the patients underwent total thy－roidectomy and prophylactic operation of bilateral CLN dissection. The relationship between the sex，age，diameter of primary tumor，and number of lesions and CLN metastasis was analyzed. Results：There was a significant difference in CLN metastasis rate between the patients aged >45 years and the patients aged ≤45 years（27.0%[67/248] vs. 44.0%[125/284]， ?字2=16.584，P=0.000） and between the patients with non-microcarcinoma and the patients with microcarcinoma（50.3%[80/159] vs. 30.0%[112/373]， ?字2=19.893，P=0.000）. However，there was no significant difference in CLN metastasis rate between the female patients and the male patients（34.9%[150/430] vs. 41.2%[42/102]， ?字2=1.415，P=0.234） and between the patients with single focal carcinoma and the patients with multifocal carcinoma（33.9%[116/342] vs. 40.0%[76/190]， ?字2=2.103，P=0.147）. Ipsilateral central lymph node（Ipsi-CLN） metas－tasis was not associated with the number of lesions（ ?字2=0.884，P=0.347），but was associated with the ipsilateral tumor diameter（ ?字2=6.648，P=0.010）. Contralateral central lymph node metastasis was not associated with the number of lesions（ ?字2=0.202，P=0.653），but was associated with the contralateral tumor diameter（ ?字2=17.268，P=0.000）. The posterior to right recurrent laryngeal nerve central lymph node（LN-prRLN-CLN） metastasis was associated with the tumor diameter of bilateral multifocal carcinoma（ ?字2=4.260，P=0.039），but was not associated with the tumor diameter of left and right unilateral single focal lesion（ ?字2=0.166，P=0.684； ?字2= 3.226，P=0.072）. Conclusion：It is recommended that PTC in cN0 T1/T2 should be routinely treated with prophylactic CLN dissection in the case of technical support. The reasonable range of CLN dissection for PTC in cN0 T1/2 should be based on individual features：1）the patients with unilateral non-microcarcinoma and bilateral multifocal carcinoma should undergo bilateral CLN dissection，especially the patients aged ≤45 years；2）the patients with unilateral single or multifocal microcarcinoma should undergo Ipsi-CLN dissection；3）LN-prRLN-CLN dissection is not necessary to do generally，but the patients with bilateral non-microcarcinoma and right non-micro－carcinoma should undergo LN-prRLN-CLN dissection.