Table 4. Prognosis of ovarian cancer in metformin users among women with type 2 diabetes.
| Authors, year | Design | Country and period | Patients | Reference group | Main results |
|---|---|---|---|---|---|
| Romero et al. 2012 (60) | Hospital-based cohort | USA 1992−2010 | 341 ovarian cancers of which 44 were in women with T2D and 16 in metformin users | Women with T2D without metformin use | PFS: HR 0.38 (95% CI: 0.16−0.90), OS: HR 0.43 (95% CI: 0.16−1.19) |
| Kumar et al. 2013 (58) | Hospital-based cohort | USA 1995−2010 | 239 ovarian cancers of which 103 were in women with T2D and 61 in metformin users | Women without metformin use, also including women without T2D | OS: HR 0.45 (95% CI: 0.26−0.83) |
| Shah et al. 2014 (61) | Hospital-based cohort | USA 2004−2009 | 305 women without DM and 62 women with T2D of which 27 were metformin users | Women with T2D and no use of metformin | PFS: metformin use 10.1 months vs. non-use 10.3 months |
| OS: metformin use 23.9 months vs. non-use 26.1 months | |||||
| Bar et al. 2016 (57) | Hospital-based cohort | Israel 2000−2012 | 143 ovarian cancers of which 22 were in women with T2D and 12 in metformin users | Women with T2D without metformin use | RFS: HR 0.14 (95% CI: 0.00−0.52) |
| Wang et al. 2017 (59) | Hospital-based cohort | China 2011−2014 | 568 ovarian cancer cases of which 48 in metformin users | Women with T2D without metformin use | PFS HR 0.34 (95% CI: 0.27−0.67) |
| OS HR 0.29 (95% CI: 0.13−0.58) | |||||
| Garcia et al. 2017 (62) | Register-based cohort and nested case-control | USA 2007−2011 | 2,291 ovarian cancers of which 552 were in women with T2D and 172 in metformin users | Women without metformin use, also including women without T2D | OS: HR 0.96 (95% CI: 0.75−1.23) |
| Urpilainen et al. 2018 (63) | Register-based cohort | Finland 1998−2013 | 421 ovarian cancer cases of which 77 were in women who used only metformin and 100 were in women who used metformin combined with some other oral ADM | Women with T2D who used other oral ADM | OC mortality HR 1.15 95% CI: 0.74−1.79) |
| Mortality from other causes HR 1.85 (95% CI: 0.44−7.73) |
T2D, type 2 diabetes; DM, diabetes mellitus; ADM, antidiabetic medication; PFS, progression-free survival; HR, hazard ratio; CI, confidence interval; OS, overall survival; RFS, recurrence-free survival; OC, ovarian cancer.