To what extent is risk grouping method successful in deciding surgical staging in endometrial cancer?

The aim of this investigation was to evaluate the success rate of risk grouping method for staging surgery by exploring the rate of lymph node metastasis (LNM) in patients with endometrial cancer (EC) according to low-risk (LR) and high-risk (HR) groups.

Patient files were reviewed retrospectively and the data of 268 patients were included in the study who underwent lymph node dissection (LND) for EC. Nodal status, histopathologic type, myometrial invasion (MI), tumor size (TS), and grade (G) were evaluated. In the LR group, all the criteria were required (G 1-2, <1/2 MI, type 1 histology, <2 cm TS), but in the HR group, one of them was enough (G 3 or ≥1/2 MI or type 2 histology or ≥2 cm TS).

A total of 84 (31.3%) and 184 (68.7%) patients were grouped LR and HR, respectively. In total, 23 patients had LNM (8.5%) out of 268 surgically staged EC patients. Lymph node metastasis was significantly (p = 0.001) more common in the HR group of patients (2.4%, 2/84 LR vs 11.4%, 21/184 HR). Cancer-specific survival (CSS) rates in groups were 96.8% and 88.6%, respectively (p = 0.009).

In patients with EC, there is a significant difference between LR and HR groups for LNM and CSS rates. But this method of stratification is not adequate to separate them for deciding whether surgical staging is mandatory. Moreover, even most of the HR patients (163/184, 88.6%) are exposed to unnecessary LND. Perhaps they are not really HR and the HR definition needs to be revised.