Background: The examination of a sentinel lymph node (SLN), where lymph node metastasis first occurs, may be advocated as an alternative staging technique. The aim of this study was to evaluate the feasibility and detection rates of an SLN biopsy in patients with endometrial cancer.
Study design: Two hundred and eleven patients with endometrial cancer underwent an SLN biopsy at hysterectomy using three kinds of tracers including 99m-technetium-labeled tin colloid (99mTc), indigo carmine and indocyanine green. Factors related to the side-specific detection rate, sensitivity and false negative rate were analyzed.
Results: The detection rates of the SLN biopsy using 99mTc, indigo carmine and indocyanine green were 77.9, 17.0 and 73.4%, respectively. The detection rate was lower in elderly patients (≥60 years) (67.9 vs 89.2%, p < 0.01), patients with >50% myometrial invasion (68.3 vs 85.2%, p < 0.01), patients with high-grade tumors (69.5 vs 84.9%, p < 0.01) and patients who underwent laparotomy (71.2 vs 84.9%, p < 0.01). There were no significant differences in body mass index. The sensitivity was not significantly different in any factor. However, the false negative rate was higher in patients with > 50% myometrial invasion (11.5 vs 1.2%, p < 0.01), high-grade tumors (13.3 vs 0.8%, p < 0.01) and who underwent laparotomy (12.2 vs 0.4%, p < 0.01).
Conclusion: Patients who underwent laparoscopy with < 50% myometrial invasion and low-grade tumors not only have higher detection rates, but also have lower false negative rates. These patients may avoid systemic lymphadenectomy according to the status of the SLN biopsy.
Keywords: Endometrial cancer; Laparoscopic surgery; Lymph node metastasis; Lymphadenectomy; Pelvic lymph node; Sentinel lymph node.