Prognostic significance of co-existent adenomyosis on outcomes and tumor characteristics of endometrial cancer: A meta-analysis

Abstract

Objective: Published data on the impact of co-existent adenomyosis on the prognosis of patients with endometrial cancer remains elusive, with studies reporting conflicting results. We conducted this meta-analysis to evaluate the prognostic significance of co-existent adenomyosis on clinical outcomes and tumor characteristics of endometrial cancer patients.

Methods: A comprehensive literature review of multiple databases was conducted; quality assessment of eligible studies was performed by the Newcastle-Ottawa scale (NOS). The outcomes of interest were compared in endometrial cancer patients with or without adenomyosis. Hazards ratios (HR) and Odds ratios (OR) with 95% confidence interval (CI) were calculated as a measure of effects.

Results: Fourteen retrospective observational studies comprising 1308 endometrial cancer patients with adenomyosis and 3734 patients without adenomyosis were included in this meta-analysis. Results indicated that endometrial cancer patients with adenomyosis was significantly associated with an increased overall survival rate (HR = 0.51; 95% CI = 0.38-0.69; P < 0.00001), but not with disease-free survival rate (HR = 0.68; 95% CI = 0.30-1.53; P = 0.35); besides, significantly associated with decreased ratio of deep myometrial invasion (OR = 0.45; 95% CI = 0.33-0.60; P < 0.00001), lymphovascular space invasion (OR = 0.44; 95% CI = 0.29-0.68; P = 0.0002), an increased ratio of histological grade 1 (OR = 1.84; 95% CI = 1.34-2.53; P = 0.0002) and FIGO I-II (OR = 1.85; 95% CI = 1.49-2.30; P < 0.00001). However, there was no significant difference in pathological type and lymph node metastasis. There was a low to high heterogeneity with I² ranging from 0 to 67%.

Conclusion: This meta-analysis indicated that co-existent adenomyosis with endometrial cancer is associated with favorable tumor characteristics and could serve as a potential protective factor for the prognosis of endometrial cancer.

Keywords: adenomyosis; endometrial cancer; meta-analysis.