Patients with endometrial cancer at risk for lymphatic metastasis should undergo pelvic and periaortic lymphadenectomy as part of their initial surgery

Most adenocarcinomas of the uterine corpus remain confined to the organ of origin. Some will metastasize. Many cancer surgeons have performed and continue to perform pelvic and periaortic lymphadenectomy in addition to hysterectomy to detect those metastases with the expectation that the findings will inform further therapy. If no lymphatic metastases are found, the patient may be spared toxic adjuvant therapy. If lymphatic metastases are identified by lymphadenectomy, then tumor-directed therapy is often successful. If lymphatic metastases are not detected and lymphatic recurrence develops, successful treatment is only occasionally achieved. Some have questioned the necessity of lymphadenectomy; they presumably believe that ignorance of lymphatic metastasis does not compromise patient outcomes. Compelling data show that lymphadenectomy is diagnostic and therapeutic. The Gynecologic Oncology Group (GOG) reported the surgicopathological features of 621 patients with carcinoma of the endometrium that preoperatively appeared to be confined to the uterus. In protocol 33, all patients were treated with primary surgery, which consisted of total abdominal hysterectomy, bilateral salpingo-oophorectomy, selective pelvic and para-aortic lymphadenectomy, and peritoneal cytology. Extrauterine metastases were found in 22% (lymph nodes, adnexa, intraperitoneal, and/or malignant cells in peritoneal washings). In half of those (11%), the metastases were in the pelvic (9%) and/or periaortic (6%) lymph nodes. Fewer than 10% of those metastatic nodes were palpably enlarged. Without lymphadenectomy, 90% of the lymphatic metastases would have gone undetected. The risk of lymph node metastasis increased with the depth of myometrial invasion and the histologic grade. This allowed some grouping based on uterine factors and their associated risk of lymphatic metastases (Table 1). Largely because of this study, the International Federation of Gynecology and Obstetrics accepted a surgically based staging system, including lymphadenectomy, for endometrial cancer in 1988. Since then, there has been debate about whether lymphadenectomy is merely diagnostic or also could be therapeutic. Kilgore et al reported on 649 patients who were surgically managed. Those undergoing multiple-site pelvic node sampling had significantly better survival than patients without node sampling (P 5 .0002). In a comparison of patients receiving whole pelvic radiation for grade 3 lesions or deep myometrial invasion, patients with multiple-site pelvic node sampling had better survival than those whose nodes were not sampled (P 5 .0027). Overall, those undergoing lymph node removal had better survival than those without lymph node removal who then received postoperative radiation. Cragun et al reported that patients with poorly differentiated cancers with 11 or more lymph nodes removed had improved survival (hazard ratio, 0.25) and progression-free survival (hazard ratio, 0.26) in comparison with those with fewer than 11 lymph nodes removed. However, the number of lymph nodes removed was not predictive of survival outcomes among those with grade 1 and 2 tumors. This association between lymphadenectomy and improved survival remained when they controlled for adjuvant radiation. This reinforced the impact of selective lymphadenectomy. A review of Surveillance, Epidemiology, and End Results data for 12,333 women was published by Chan et al. Among the intermediate/high-risk patients (stage IB/grade 3 and stages IC-IV/all grades), more extensive lymph node resection (1, 2-5, 6-10, 11-20, and >20 nodes) was associated with improved 5-year disease-specific survival across all 5 groups (75%, 82%, 84%, 85%, and 87%, respectively; P< .001). For stage IIIC-IV patients with nodal metastases, the extent of node resection significantly improved the survival rate from 51% to 53% to 53% to 60% to 72% (P< .001). However, there was no benefit of nodal