An analysis of the significance of the lymph node ratio and extracapsular involvement in the prognosis of endometrial cancer patients

Abstract

Introduction: The primary aim of our study was to analyse the impact of the lymph node ratio (LNR) and extracapsular involvement (ECI) on the prognosis of endometrial cancer (EC) patients.

Material and methods: We carried out a retrospective analysis of 886 patients surgically treated for EC between 2000 and 2015. In the subgroup of patients with lymph node metastases (LNM), we evaluated the impact of the number and localization of the LNM, LNR, and ECI on patients' overall survival (OS).

Results: In the group of patients with LNM, 0.3 was the optimal LNR cut-off for differentiating between short- and long-term survivors [HR = 2.94 (95% CI: 1.49-5.80)]. Patients with a LNR ≥ 0.3 had a significantly shorter OS period (35.0 months, range 0.2-175 months) compared to patients with a LNR < 0.3 [median OS - mOS, was 143, range 15-169 months; (p = 0.003]. We observed significant differences in the mOS of EC patients without LNM compared to patients with LNM, as well as those with both LNM and ECI (p < 0.0001). In the group of patients with LNM, we also found that a poorer prognosis depended on the extension of the primary tumour.

Conclusions: Our results suggest that when LNM are found, the long-term outcomes of EC patients are worse in those who have a LNR ≥ 0.3, the presence of ECI, and a more advanced extension of the primary tumour.

Keywords: endometrial cancer; extracapsular involvement; lymph node metastases; lymph node ratio; lymphadenectomy.

Fig. 1

Survival of endometrioid endometrial cancer (EEC) patients according to lymph node metastases (LNM). Group 0: patients (n = 562) without LNM; Group 1: patients (n = 68) with LNM; Group 2: patients (n = 7) with extracapsular involvement (ECI); (p < 0.0001) (A), Survival of EEC patients according to the site of lymph node metastases. Group 1: patients (n = 15) with only pelvic lymph node metastases; Group 2: patients (n = 16) with paraaortic lymph node metastases; (p = 0.26) (B), survival of EEC patients according to lymph node ratio (LNR). Group 1: patients (n = 51) with a LNR < 0.3; Group 2: patients (n = 24) with LNR ≥ 0.3; (p = 0.003) (C), survival of EEC patients with LNM according to the extension of the primary tumour (T parameter from TNM classification). Group 1: patients (n = 49) with T1 tumour; Group 2: patients (n = 22) with T2 tumour; Group 3: patients (n = 3) with T3 tumour; (p = 0.008) (D)