Objective This study aimed to evaluate the efficacy and safety of oral progestin treatment for early-stage endometrial cancer.

Methods We conducted a systematic review and meta-analysis of the proportions from observational studies. Original studies were selected if patients with early-stage endometrial cancer, especially those of reproductive age, were treated with oral progestin. We conducted searches on studies listed in MEDLINE, EMBASE, and Cochrane that were published through June 2014, and relevant articles were also searched. The methodological quality of the included studies was assessed using the Newcastle-Ottawa quality assessment scale. Funnel plots and metaregression analyses were used to assess bias.

Results The final sample included 25 articles involving 445 patients. Based on a random-effects model, patients achieved a disease regression rate of 82.4% (95% confidence interval [CI], 75.3%–88.7%), a relapse rate of 25.0% (95% CI, 15.8%–35.2%), a pregnancy rate of 28.8% (95% CI, 22.5%–35.5%), and a live birth rate of 19.6% (95% CI, 12.8%–27.4%). Body weight gain, liver dysfunction, and abnormal blood coagulation test results were the most common treatment-related adverse effects. Only 2 disease-related deaths were reported during the follow-up duration.

Conclusions Based on the present systematic review and meta-analysis, oral progestin treatment is feasible and safe for patients of reproductive age.