Significance of lymph node metastasis on survival of women with uterine adenosarcoma.

OBJECTIVE: Uterine adenosarcoma (UAS) is a rare gynecologic malignancy and the significance of lymph node metastasis on survival has not been well studied.

METHODS: A retrospective study was performed utilizing the Surveillance, Epidemiology, End Results Program to examine UAS (n=994), endometrial stromal sarcoma (ESS, n=2910), and uterine leiomyosarcoma (LMS, n=5506) diagnosed between 1973 and 2013. The impact of lymph node metastasis on cause-specific survival (CSS) was cross-compared by multivariable analysis. Systematic literature review was conducted to examine the impact of nodal metastasis on progression-free survival (PFS) in UAS.

RESULTS: UAS had the lowest incidence of lymph node metastasis among the sarcoma subtypes examined (UAS 2.9%, LMS 3.4%, and ESS 6.6%, P<0.001). Lymph node metastasis was independently associated with decreased CSS in all three tumor types (all, P<0.01); however, magnitudes of statistical significance of lymph node metastasis for CSS were similar across the three tumor types: adjusted-hazard ratio (aHR) for UAS 2.34, ESS 2.43, and LMS 2.10. Systematic literature review identified 230 unique cases of surgically treated UAS. On multivariable analysis, lymph node metastasis (aHR 4.72) had the greatest degree of significance for PFS compared to other tumor factors including sarcomatous overgrowth (aHR 2.88), heterologous elements (aHR 2.08), and deep myometrial invasion (aHR 1.51). Large tumor, deep myometrial invasion, and sarcomatous overgrowth were associated with increased risk of lymph node metastasis (all, P<0.05).

CONCLUSION: While uterine adenosarcoma had a low incidence of lymph node metastasis, the impact of lymph node metastasis on survival was comparable to ESS or LMS.