Multi-factors Analysis Of Cervical Lymph Node Metastasis In CNO Papillary Thyroid Carcinoma

Objective:To summarize the cervical lymph node metastasis in CNO papillary thyroid carcinoma. To analyze the risk factors of cervical lymph node metastasis in CNO papillary thyroid carcinoma, and guide standardized and individualized treatment to these patients.Methods:To analyze retrospectively cervical lymph node metastasis of CNO thyroid papillary carcinoma in patients who were first treated in thyroid surgery center in our hospital from January2012to January2013. Mainly research factors which may make different in cervical lymph node metastasis of CNO PTC patients, including gender, age, family history of thyroid cancer, tumor location, tumor size, thyroid capsule invasion and number of tumors, unilateral and bilateral involved,8factors in all. Then collect postoperative routine pathological reports of these patients, who will be divided into two groups, metastasis and non-metastasis group, according to the pathological reports. Apply chi-square test and t-test of SPSS18.0statistical software to carry on univariate analysis of these risk factors one by one. Then choose the meaningful factors whose difference in metastasis rate show statistical significant. Import data of these factors into binary logistic regression to decide the high risk factor to cervical lymph node metastasis of CNO PTC patients.Results:There are199CNO PTC patients selected in this research, with85cases of neck lymph node metastasis, showing that the lymph node metastasis rate is42.7%(85/199) of the whole. Jumping lymph node metastasis was found in6patients, an incidence of3%(6/199). There are papillary thyroid micro-carcinoma (PTMC)126cases in all, with a metastasis rate of31.7%(40/126); the T1group with a metastasis rate of39.7%(71/179). There are54cases of thyroid capsule invasion, lymph node metastasis found in33cases, with a lymph node metastasis rate of61%(33/54), while the group without thyroid capsule invasion shows a metastasis rate of35.9%(52/145). Multi-tumor were found in59cases, with an incidence of29.6%(59/199), of which29patients exist cervical lymph node metastasis, with a rate of49%(29/59),while the lymph node metastasis rate of single foci group lymph was40%(56/140). The P values of chi-square test of the6factors, including gender (male/female), age (≥45years/<45years),tumor location (uppe、middle and lower part), number of tumors (single/multiple) and gland involved (single/bilateral), were showed respectively0.066,0.152,0.917,0.001,0.233and0.744. P value of t-test of Maximum tumor diameter is0.000. The P values of chi-square test of micro-carcinoma(yes/no) and T1(yes/no) show respectively0.000and0.009. Importing the data of the two factors maximum tumor diameter and thyroid capsule invasion into binary logistic regression multivariate analysis. The two both show a statistically significant difference with P values of0.000and0.016.Conclusions:1.Cervical lymph node metastasis is a significant biological characteristic of papillary thyroid carcinoma. A negative cervical lymph node metastasis diagnosis can not rule out the possibility of metastasis in a pathological diagnosis after operation. Even in CN0PTMC patients a high cervical lymph node metastasis rate could be found..2.Cervical lymph node metastasis generally involves the ipsilateral central lymph node firstly, but jumping lymph node metastases is not rare. Metastasis rate of neck lateral lymph nodes increase when the thyroid capsule is invaded and (or) a high metastasis central lymph node number or a high metastasis rate of central lymph nodes. So a careful exploration of the ipsilateral lateral lymph nodes should be done in patients in high risk.3.Thyroid capsule invasion, and tumor size are risk factors for cervical lymph node metastasis in PTC patient, while other factors including gender, age, location and tumor number, involving unilateral or bilateral grand, are showed no significant correlation to cervical lymph node metastasis. 4. Ipsilateral central lymph nodes of CNO patients should be cleaned routinely at first operation. FND or SND should be implemented if pathological diagnosis shows metastasis in lateral neck lymph nodes. A careful exploration of lateral lymph area should be done in the patients with high risk factors.