Preoperative biopsy and intraoperative tumor diameter predict lymph node dissemination in endometrial cancer

Objective: To determine whether preoperative biopsy (grade and histology) and intraoperative tumor diameter (TD) predict lymph node dissemination (LN +) and lymph node recurrence (LNRec) in endometrial cancer (EC). Methods: Patients who underwent EC surgery from 2004 to 2008 were stratified into risk categories. Cases with preoperative grade 3 or non-endometrioid histology were classified as high risk (HR). Patients with preoperative FIGO grade 1 or 2, endometrioid histology or complex and/or atypical hyperplasia were classified based on intraoperative findings: (a) intraoperative macroscopic extrauterine disease classified as HR; (b) largest TD > 2 cm classified as intermediate risk (IR) and (c) TD ≤ 2 cm classified as low risk (LR). LN + and LNRec rates were determined. Results: Of 704 patients evaluated, 188 were HR (27%), 350 IR (50%), and 166 LR (23%). P/PA lymphadenectomy was performed in 87% HR, 83% IR and 16% LR patients. LN + and/or LNRec occurred in 51 HR patients (27%) and 39 IR patients (11%). Only 1 LR patient (0.6%) had LN + and none had LNRec. Four LR patients (2%) required adjuvant therapy according to permanent section pathology. Conclusions: Preoperative biopsy and intraoperative TD can be used to effectively stratify patients into LR, IR or HR subgroups to tailor surgery. LR patients have a low probability (< 1%) of LN + and/or LNRec and lymphadenectomy can be omitted in this group. HR and IR patients combined (3/4 of population) have a substantial risk of LN + or LNRec (17%). Lymphadenectomy is proposed to be advantageous in HR and IR patients if accurate frozen section is lacking.