Histopathological prognostic factors predicting para-aortic lymph node metastasis in patients with endometrioid uterine cancer

Introduction: The purpose of this study was to determine histopathological factors for para-aortic lymph node (PALN) metastasis in patients with endometrioid uterine cancer.

Methods: A total of 355 patients (Stage I, n=269; II, n=24; and III, n=62) (FIGO 2009) underwent primary radical surgery including complete systematic pelvic lymph node (PLN) and PALN dissection in Tohoku Gynecologic Cancer Unit (TGCU) between 1993 and 2004. Logistic regression analysis was used to determine the independent prognostic factors for PALN metastasis.

Results: Multivariate analysis revealed that PLN metastasis (p<0.0001) and ovarian metastasis (p=0.0080) related with PALN metastasis. Moreover, among the sites of PLN metastases, obturator lymph node (LN) [risk ratio (RR): 16.9, 95% confidence interval (CI): 4.3-66.4, p<0.0001] and common iliac LN (RR: 7.1, 95% CI: 1.1-44.5, p=0.0375) related with PALN metastases. In detection of PALN metastasis, combination of obturator LN and/or common iliac LN and/or ovarian metastasis (A) revealed 75.9% sensitivity (22/29) and 97.8% negative predictive value (NPV) (304/311). However, by combination of obturator LN metastasis and/or common iliac LN metastasis and/or grade 3 and/or deep myometrial invasion (B), the detection of PALN metastasis was 100.0% sensitivity (29/29) and 100.0% NPV (198/198). Also, 55.8% (198/355) of patients could have avoided PALN dissection by combination B.

Conclusions: These results suggest that PALN dissection is necessary when combination B is positive by pre- and intra-operative assessments. Further prospective randomized controlled studies need to be conducted in a larger patient population to establish the strategy for detecting PALN metastasis utilizing pre-/intra-operative assessments.