Background: Additional tools are needed to improve the selection of women with early-stage endometrial cancer (EC) at increased risk of nodal metastases and/or recurrence to adapt surgical staging and adjuvant therapies. The aim of this study was to assess the impact of EC tumor size on nodal status and recurrence-free survival (RFS) according to European risk groups for recurrence.
Methods: Data of 633 women with early-stage EC who received primary surgical treatment between 2001 and 2012 were abstracted from a multicenter database. Optimal tumor size cut-offs were determined by a minimal p value approach according to final nodal status. Logistic regression was used to determine the impact of defined tumor size on nodal involvement, and the Kaplan-Meier method was used to estimate the survival distribution.
Results: The number of women with final low-, intermediate-, and high-risk EC was 302, 204, and 127, respectively. Tumor size was correlated with nodal status and RFS in women with low-risk EC, while no correlation was found for women with intermediate/high-risk EC. Tumor size ≥35 mm emerged as the optimal threshold for a higher rate of nodal involvement (odds ratio 4.318, 95 % CI 1.13-16.51, p = 0.03) and a lower RFS (p = 0.005) in women with low-risk EC.
Conclusion: Tumor size is an independent prognostic factor of lymph node involvement in women with low-risk EC and could be a valuable additional histological criterion for selecting women at increased risk of lymph node metastases to better adapt surgical staging.