Clinical Study Of Distal External Iliac Lymph Nodes Metastasis In Early Stage Cervical Cancer

Radical hysterectomy and pelvic lymphadenectomy are the standard treatment for earlystage cervical cancer. Although nodal status is not included in the International Federation ofGynecology and Obstetrics (FIGO) clinical staging system, it is one of the most importantprognostic factors and decision criterion for adjuvant therapy in patients with early stagecervical cancer. Thus, pelvic lymphadenectomy has become an integral part of the surgicalmanagement of cervical carcinoma. Systematic pelvic lymphadenectomy was performed byskeletonizing vessels and removing the lymphatic tissues about the internal iliac, external iliac,common iliac, and obturator regions. Numerical data shows that，more than70％of earlystage cervical cancer patients with no pelvic lymph nodes metastases suffer from the vascularnerve injury and risk of lymphocyst which caused by pelvic lymphadenectomy．Additionally，due to the removing too many of normal lymph nodes， local immune function isdepressed．Therefore, pelvic lymphadenectomy is still controversial issue for patients withdifferent stages of cervical cancer, in the present.In this study, the distal external iliac lymph nodes are located along the external iliacartery between the inguinal ligament and the deep circumflex vein. The number of this lymphnode is relatively small, generally2~5lymph nodes, and removing the lymph nodes was moredifficult, after excision of easy to increase the incidence rate of complications intraoperativebleeding volume, lower limb lymphedema and lymphatic cyst operation, at the same time,prolongs the operation time. In the past, we were often referred to as deep inguinal lymphnodes, in fact the deep inguinal lymph nodes are located in the femoral vein and the upperfemoral canal, usually1~4medals, and femoral arteries, veins. It is not included in the scopeof pelvic lymphadenectomy during radical surgery for early stage cervical cancer. Many scholars had studied the distribution of pelvic lymph nodes and sentinel lymph nodemetastasis. But the distribution of distal external iliac lymph nodes was rarely reported.The result shows that distal external iliac lymph nodes metastasis is rare in patients withearly stage cervical cancer, especially in cases without pelvic lymph nodes metastasis. Andthe incidence of isolated distal external iliac lymph nodes is very low. Thus, less extensivepelvic lymphadenectomy may be considered in these patients in order to reduce operationcomplications and improve patient’s quality of life. The deep circumflex iliac vein was anappropriate landmark for the caudal limit of external iliac lymphadenectomy.ObjectivesOur study aimed to investigate the incidence of metastases in pelvic lymph node anddistal external iliac lymph node and its associations with clinicopathological factors inpatients with early stage cervical cancer, and determine the role of distal external iliac lymphnodes dissection in the surgery. The distal external iliac lymph node located along the externaliliac artery between the deep circumflex iliac vein and the inguinal canal. The distal externaliliac lymph nodes are located along the external iliac artery between the inguinal ligament andthe deep circumflex vein (the vein formed by the union of the veins accompanying the deepiliac circumflex arteries, which drain into the external iliac vein above the inguinal ligament).MethodsWe retrospectively studied524patients with FIGO stageⅠa-Ⅱa cervical cancer inShandong Cancer Hospital and Institute from June1995to December2011. All patientsunderwent complete bilateral pelvic lymphadenectomy with or without para-aortic lymphnodes biopsy, followed by radical hysterectomy. The metastatic rate and distribution of thepelvic lymph nodes and distal external iliac lymph nodes were analyzed. All patients wereremoved the distal external iliac lymph nodes. The following aspects are analyzed：(1)thedistribution pattern of pelvic lymph nodes;(2)the relationship between pelvic lymph nodemetastasis and clinical pathological parameters;(3)the relationship between distal externaliliac lymph node metastasis and clinical pathological parameters;(4)the relationship betweenthe metastatic pattern of distal external iliac lymph node and the pelvic lymph nodes (excluding distal external iliac lymph nodes) metastasis;(5)the relationship between negativepelvic lymph nodes, the metastatic status of pelvic lymph node (except the distal external iliaclymph nodes), distal external iliac lymph node and the survival rates of patients with earlystage cervical cancer.ResultsOf the524patients,124(23.7%) had pelvic lymph nodes metastasis. The metastatic ratewas16.0%(85of524patients) in the obturator lymph nodes,12.2%(64of524patients) inthe internal and external iliac lymph nodes,2.9%(15of524patients) in the common iliaclymph nodes,2.1%(11of524patients) in the distal external iliac lymph nodes,1.7%(9of524patients) in the para-aortic nodes. The incidence of isolated positive distal external iliac lymphnodes was0.2%. The pelvic lymph node metastatic rate was0.9%in stageⅠB1,1.3%instage ⅠB2,3.3%in stageⅡA1and2.6%in stageⅡA2. No patient had pelvic lymph nodemetastasis at stage ⅠA. Univariate analysis showed that lymph vascular space invasion, deepstromal invasion, FIGO stage were associated with pelvic lymph nodes metastasis (P<0.05).And lymph vascular space invasion, pelvic lymph nodes metastasis (excluding distal externaliliac lymph nodes) were also associated with distal external iliac lymph nodes metastasis(P<0.05). Binary logistic regression analysis showed that lymph vascular space invasion(OR=2.809,95%CI=1.802-4.379) and deep stromal invasion (OR=4.093,95%CI=2.196-7.628) were found to be the independent risk factors for metastases to pelviclymph nodes. And pelvic lymph nodes metastasis (excluding distal external iliac lymph nodes)was the independent risk factor for metastasis to distal external iliac lymph nodes. The5-yearoverall survival (OS) was87.9%in patients with negative lymph nodes, and58.6%was inthose with positive pelvic nodes. The1-year,2-year, and3-year OS were50.9%,33.3%and0in patient with positive distal external iliac lymph nodes, respectively.ConclusionsIn early stage cervical cancer, distal external iliac lymph nodes metastasis is rare,especially in cases without pelvic lymph nodes metastasis and in stage ⅠA. And theincidence of isolated distal external iliac lymph nodes is very low. Thus less extensive pelviclymphadenectomy may be considered in these patients in order to reduce operation complications and improve patient’s quality of life. The deep circumflex iliac vein was anappropriate landmark for the caudal limit of external iliac lymphadenectomy. But ifintra-operative rapid pathological clear patients with pelvic lymph nodes metastasis(excluding distal external iliac lymph nodes), systematic pelvic lymphadenectomy may beconsidered in these patients in order to reduce the patients with distant metastasis rate, and itshould also include the removal of the distal external iliac lymph nodes.