Prognostic significance of lymph node metastasis patterns in endometrial cancer.
Hogan K, Divine G, Elshaikh M, Munkarah A, Bergman D, and Allo G. Prognostic significance of lymph node metastasis patterns in endometrial cancer. Lab Invest 2018; 98:423-424.
Background: The clinical significance of the size and extracapsular extension (ECE) of lymph node (LN) metastasis is not clear. With the advent of sentinel LN biopsies in endometrial cancer, prognostic significance of lymph node metastasis pattern is critical and may guide further management. Design: This is a retrospective study of patients with endometrial cancer metastatic to regional LN, who underwent treatment at our institution between 1986 and 2007. After IRB approval, we assessed histologic dimension of largest LN metastasis, and presence of ECE. LN metastases are classified as macrometastases (when => 2mm) and micrometastasis (when <2mm). Clinical data were collected from the medical records. Descriptive analysis and Cox regression models were produced. Results: 126 cases fit our inclusion criteria. Mean age at diagnosis was 65yrs (37-85). Of those, 65 (52%) were considered type 1. LN metastasis was classified as macrometastasis in 92 (73%) cases, including 42 (46%) type 1 cancers. ECE was identified in 33 (26%) cases, including 11 (30%) type 1 cancers. Within the entire sample, LN macrometastasis was significantly associated with recurrence (HR, 3.3; p=0.02), but not overall survival (HR, 1.27; p=0.5). This effect is not significant when adjusting for histologic type, and adjuvant treatment received (HR, 0.78; p=0.519). ECE was associated with worse overall survival and recurrence free survival, within the entire sample (HR, 2.5; p=0.003 and HR, 3.5; p<0.001, respectively) and within type 1 endometrial cancers (HR, 5.4; p=0.001, and HR, 7.23; p<0.001, respectively) but not within type 2 endometrial cancers, where ECE was more common (HR, 1.28; p=0.515). After adjusting to tumor type and adjuvant treatment received, ECE is still associated with worse overall and recurrence-free survival (HR, 2.65; p=0.003 and HR, 4.41; p<0.001, respectively). Conclusions: As the size of lymph node metastasis does not significantly influence survival, lymph node micrometastasis should be carefully searched for within the surgical specimens. This, in addition to the adverse outcome related to ECE, extensive pathologic lymph node sampling, using protocols that detect <0.2 cm metastasis and preserve perinodal fat, may be implemented. Routine reporting of ECE is also recommended. (Figure Presented).