A multi-center retrospective study comparing one-step nucleic amplification and conventional ultrastaging for sentinel lymph node assessment in early-stage endometrial cancer.

OBJECTIVE

This study aimed to compare one-step nucleic acid amplification with conventional histopathological ultrastaging for sentinel lymph node assessment in patients with uterine-confined endometrial cancer. The primary endpoint was to evaluate differences in diagnostic performance in routine clinical practice. The secondary endpoint was to evaluate differences in oncological outcomes.

METHODS

We conducted a multi-center retrospective study including patients with pre-operatively uterine-confined endometrial cancer who underwent sentinel lymph node biopsy. Two independent cohorts were analyzed: one in which conventional ultrastaging (serial hematoxylin and eosin staining and immunohistochemistry) was performed, and another assessed using one-step nucleic acid amplification. Only patients with a minimum follow-up of 2 years were included in the analysis.

RESULTS

A total of 945 patients were included (immunohistochemistry = 653; one-step nucleic acid amplification = 292). Overall, 11.6% (n = 109) of cases were positive, predominantly with low-volume disease-isolated tumor cells 3.0% (n = 28), micrometastases 4.0% (n = 38), macrometastases 4.6% (n = 43). Both methods demonstrated high diagnostic accuracy with low false-negative rates (overall 1.9%; immunohistochemistry = 1.6%, one-step nucleic acid amplification = 2.8%). Median follow-up was 3.6 years. Three-year overall survival was 92.2% (95% confidence interval 90.0% to 93.9%), with comparable survival rates between immunohistochemistry (92.8%, 95% confidence interval 90.2% to 94.7%) and one-step nucleic acid amplification (90.9%, 95% confidence interval 86.2% to 94.0%, p =.929). The ultrastaging method was not associated with overall survival in the Cox multi-variate analysis.

CONCLUSIONS

Sentinel lymph node assessment using one-step nucleic acid amplification and conventional immunohistochemistry ultrastaging did not show significant differences in accuracy for detecting nodal metastases and yielded comparable oncological outcomes, both in overall and disease -free survival. These findings reflect real-world clinical practice, supporting the reliability of both techniques for endometrial cancer staging and suggesting that the choice of sentinel lymph node evaluation method does not affect long-term patient outcomes.