Metformin Use and Mortality in Women with Ovarian Cancer: An Updated Meta-Analysis

Table 1

Characteristics of the included studies.

Study	Design	Country	Patient characteristics	Patient number	Mean age (years)	FIGO stage	Definition of metformin use	Median follow-up durations (years)	Mortality validation	Variables adjusted
Currie, 2012	R	UK	Women with OC	5126	67.5	NR	Metformin use 30 days before or after OC diagnosis by pharmacy records	2.1	Medical database	Age, smoking history, Townsend index of deprivation, CCI, number of primary care contacts, and year of diagnosis
Romero, 2012	R	USA	Women with epithelial OC	341	59.2	I–IV	Metformin use 30 days before OC diagnosis	5.3	Medical database	Age, BMI, creatinine, histological subtype, grade, and FIGO stage of the tumor
Kumar, 2013	R	USA	Women with OC	239	60.4	I–IV	Metformin use before OC diagnosis by pharmacy records	4	Medical database	Age, BMI, grade, histology, and chemotherapy
Shah, 2014	R	USA	Women with epithelial OC	367	63.5	I–IV	Metformin use before OC diagnosis by medical records	4.8	Medical database	Age, stage, grade, histology, debulking status, BMI, and chemotherapy
Bar, 2016	R	Israel	Women with OC	143	62.5	I–IV	Metformin use after OC diagnosis by pharmacy records	4.1	Medical database	Age, stage, use of neoadjuvant chemotherapy, the presence of DM, HTN, and concurrent medications
Garcia, 2017	R	USA	Women with OC	2291	73	I–IV	Metformin use 6 months before or after OC diagnosis by pharmacy records	5	Medical database	Age, race, diagnosis year, stage, histology, grade, DM, and CCI
Wang, 2017	R	China	Women with OC	568	57.9	I–IV	Metformin use after OC diagnosis by pharmacy records	4.9	Medical database	Age, histological subtype, grade, BMI, smoking, type of surgery, postoperative residual disease, and chemotherapy
Urpilainen, 2018	R	Finland	Women with T2DM and OC	421	71	I–IV	Metformin use before OC diagnosis by pharmacy records	7.2	Medical database	Age, diagnosis year, duration of DM, stage, and concurrent medications
Gonzalez, 2020	R	USA	Women with stage IIIC and IV epithelial OC	534	64	III-IV	Metformin use after OC diagnosis by pharmacy records	4.8	Medical database	Age, race, CCI, stage, chemotherapy, histology, residual disease status, and concurrent medications

FIGO, International Federation of Gynecology and Obstetrics; R, retrospective; OC, ovarian cancer; NR, not reported; CCI, Charlson comorbidity index; BMI, body mass index; DM, diabetes mellitus; HTN, hypertension.