Introduction/Background Sentinel lymph node (SLN) mapping with indocyanine green (ICG) has become the standard of care in apparent early-stage endometrial cancer. The aim of this study is to evaluate the possible risk factors (RFs) for lymph-nodal metastases, differentiating by the type of metastasis.

Methodology This is an observational single-center retrospective study. We reviewed 96 patients with a diagnosis of apparent early-stage endometrial cancer submitted to hysterectomy with salpingo-oophorectomy and SLN mapping from December 2015 to March 2022. Possible RFs for nodal metastasis were considered including clinical (age, BMI), and biochemical (CA125, CA 19.9, HE-4) parameters, anatomopathological characteristics (Myometral invasion – MI, Lymphovascular space invasion (LVSI), grade, histotype) and immunohistochemical findings (L1CAM, Ki67, estrogen receptor – ER, progesterone receptor- PR). Odds ratios (ORs) were calculated, and then RFs were confronted with logistic regression.

Results Overall detection rate was 94.8%, 83.3% bilateral, and 11.5% unilateral. We removed 181 suspected SLNs. The preponderance of SLNs was found at the external iliac and interiliac stations (69%). 7 patients had macrometastases, 5 micrometastases, and 7 ITCs. Higher ER percentage resulted in a protective factor (PF) for lymph nodal metastasis. MI more than 50%, LVSI, and p53 positivity resulted in RFs for lymph nodal metastases. Histotype, age, and L1CAM showed a slight, not significant, correlation as possible RFs. The multivariate multinomial analysis didn’t find any statistically significant differences between the RFs and the type of metastasis.

Conclusion Our study shows a good SLN detection rate in line with the literature. The multivariate multinomial analysis shows that there are no differences in the RFs for the different types of metastases suggesting that these entities are a pathological continuum. Further studies are needed.