Preoperative selection of endometrial cancer patients at low risk for lymph node metastases: useful criteria for enrollment in clinical trials

midst of the ongoing debate on the extent and therapeutic value of lymphadenectomy in endometrial cancer. Several groups have recognized that preoperative and intraoperative identification of low risk patient groups may allow the omission of lymphadenectomy thereby averting unnecessary morbidity and reducing costs while potentially achieving favorable oncologic outcomes [1-9]. Although the role of lymphadenectomy in endometrial cancer continues to be a topic of controversy, patients with low risk features (grade 1 or 2 histology, less than 50% myometrial invasion, endometrioid histology, tumor diameter ≤2 cm and absence of extrauterine disease) have been consistently shown to have a substantially low (<1%) risk of lymphatic dissemination [2,10,11]. Nevertheless, the aim of this editorial and the current paper is not to further deliberate the role of lymphadenectomy in endometrial cancer, but to describe preoperative risk stratification criteria that allow the identification of low-risk patients. The authors of the current paper evaluate a population of 56 patients with low risk endometrial cancer who were surgically treated without lymphadenectomy (5 of which had lymphadenectomy based on intraoperative evaluation) [12]. These patients were preoperatively selected on the basis of their low lymph node metastasis risk score, which incorporates preoperative histologic grade, tumor volume (measured by magnetic resonance imaging [MRI]) and serum CA-125. Additionally MRI criteria for myometrial invasion and extrauterine disease were assessed and included in the decision to omit lymphadenectomy. The authors conclude that patients preoperatively selected on the basis of a lymph node metastasis score of 0 and absence of myometrial invasion or extrauterine disease by MRI have an excellent disease prognosis as demonstrated by the low risk of recurrence (1.8%) and 100% overall survival. The authors build on their previous extensive experience with preoperative identification of low-risk endometrial cancer patients. They have previously shown that tumor volume, measured by MRI, serum CA-125 and preoperative tumor grade were independent risk factors for lymph node metastasis [6]. A similar study by the Korean Gynecologic Oncology Group recently showed that preoperative serum CA-125 in addition to deep myometrial invasion, lymph node metastasis, and extrauterine disease (both evaluated by MRI) identified low-risk patients for lymph node metastasis with high accuracy [8]. These criteria have been validated in two Japanese cohorts [13]. In the medical literature, data on the preoperative evaluation of the risk of lymph node metastases in endometrial cancer are limited. Imaging modalities per se, including computed tomography (CT), MRI, positron emission tomography (PET)/ CT, are inadequate diagnostic tools for predicting lymph node status in patients with uterine malignancy [14]. However, when combined with other predictors (as in the present study), these imaging modalities may in fact aid in patient selection. For example, 40% to 50% of patients with positive nodes are found to have enlarged/suspicious lymph nodes on CT scan or MRI. Therefore, information on the size and characteristics of the lymph nodes may be helpful in having a more accurate estimate of the risk of lymph node metastases, in combination with other risk factors [15]. On the other hand, the sensitivity and specificity of CA-125 in the detection of Preoperative selection of endometrial cancer patients at low risk for lymph node metastases: useful criteria for enrollment in clinical trials