Table 1

Characteristics of included studies ordered by date of publication

Author (year)RegionDesignTotal No of patientsNo of patients in treatment groupsIntervention dosageAge at diagnosis (years)*Histological diagnosis, n (%)Reported outcomesMedian follow-up (months)Study period
Matsuo et al (2020)21 USARetrospective, single institution245Prog: 194 (140 oral, 54 IUD)MPA, MA, NE, Depo, LNG-IUD; dosages not specified36 (30–43) for oral progestin; 36 (29.8–44.3) for IUDAEHRemission9.02003–2018
Prog+M: 51 (36 oral, 15 IUD)As above, metformin; dosages not specified35 (27–41) for oral progestin; 34 (29-39) for IUD
Acosta-Torres et al (2020)17 USARetrospective, multi-institution92Prog: 58MA 80–160 mg daily, MPA 10–40 mg daily, prometrium 400 mg daily, or LNG-IUD 52 mg36 (31–39)AEH: 33 (56.9%); EC: 25 (43.1%)Remission, relapse, live births, 5 year recurrence free survival28.41999–2018
Prog +M: 34As above, metformin 500–1000 mg daily32 (29–35)AEH: 21 (61.8%); EC: 13 (38.2%)
 Yang et al (2020)14 ChinaRandomized trial (open label), single institution150Prog: 74MA 160 mg daily33.4±5.2AEH: 62 (83.8%) EC: 12 (16.2%)Remission, relapse, pregnancy, live births, adverse effects33.4, until Feb 20192013–2017
Prog +M: 76As above, metformin 500 mg three times a day32±4.5AEH: 61 (80.3%); EC: 15 (19.7%)
Mitsuhashi et al (2019)JapanRetrospective, single institution86Prog: 23MPA 400 mg daily35 (28–45)EC†Remission, relapse, 5 year recurrence free survival, pregnancy rates, live birth rates, adverse effects572009–2017
Prog +M: 63MPA 400 mg daily, metformin 750–2250 mg daily35 (26–44)AEH: 21 (33.3%);
EC: 42 (66.7%)
Zhou et al (2015)19 ChinaRetrospective, single institution32Prog: 23MPA 250 mg daily, or MA 160 mg daily30.4
AEH: 13 (40.6%);
EC: 19 (59.4%)
Remission, relapse, pregnancy, live births32.52006–2013
Prog +M: 9As above, metformin 250 mg three times a day
Shan et al (2014)20 ChinaRandomized trial, single institution, pilot study16Prog: 8MA 160 mg daily34±7.1AEHRemission, relapse, pregnancy rates, live birth rates, adverse effects12, until Jan 20142012–2013
Prog +M: 8As above, metformin 500 mg three times a day36.4±4.2
  • *Mean±SD, or median with IQR.

  • †Twenty-three patients with endometrial carcinoma were used as historical controls, with study period from 1996 to 2017.

  • AEH, atypical endometrial hyperplasia; Depo, intramuscular depo-medroxyprogesterone acetate; EC, endometrialcarcinoma; LNG-IUD/IUD, levonorgestrel intrauterine device; MA, megestrol acetate; MPA, medroxyprogesterone acetate; NE, norethindrone; Prog, progestin therapy; Prog+M, progestin and metformin combined therapy.