The Effects of Metformin on Ovarian Cancer: A Systematic Review

Abstract

Our findings showed the potential therapeutic effects of metformin on survival outcomes of ovarian cancer and ovarian cancer prevention. However, most of the evidence was observational studies. There is a call for further well-conducted controlled clinical trials to confirm the effects of metformin on ovarian cancer survival and ovarian cancer prevention.

Metformin use and gynecological cancers: A novel treatment option emerging from drug repositioning

“…A meta-analysis of 5 studies confirmed that metformin tended to decrease the occurrence of ovarian cancer among diabetic patients (16) (Table 1a). The meta-analysis of 28 studies performed by Zhang et al (17) showed that metformin was associated with lower risk of all-cause mortality in cancer patients with diabetes, and especially for ovarian cancer (RR= 0.44, 95%CI= 0.30-0.64; p < 0.001).…”

“…Some epidemiological studies and meta-analysis have shown that metformin use is associated with decreased risk and /or reduced mortality of ovarian cancer (13)(14)(15)(16)(17) endometrial cancer (17,21,105,106) and breast cancer (22,131,132,135,136) .Metformin is especially useful for endometrial cancer prevention in women with PCOS and obesity (18,19,(97)(98)(99)(100)(101)(102)(103) and can represent a novel interesting treatment option for atypical endometrial hyperplasia or early stage, well differentiated endometrioid-type endometrial carcinoma in young women who wish to preserve fertility (94, 99,.101). As far as breast cancer is concerned, the heterogeneity of tumor subtypes makes it difficult to determine the actual benefits of metformin therapy (140) .…”

“…Metformin has been also found to reduce the incidence and mortality of ovarian cancer (13)(14)(15)(16)(17), endometrial cancer (17)(18)(19)(20)(21), and breast cancer (17,22).…”

Ovarian cancer stem cells: A target for oncological therapy

“…In the course of the disease, these women manifest longer duration to progression and display a higher 5-year survival percentage. [25][26][27][28] Numerous studies have shown that the favorable effect of metformin in the development and course of malignant tumors, including ovarian cancer, may be linked to its inhibitory effect on CSCs. [29][30][31] Studies on the SKOV3 and A2780 cell lines of ovarian cancers conducted by Zhang et al demonstrated that low doses of metformin selectively inhibit CSCs with markers CD44+ and CD117+, and inhibit epithelial mesenchymal transition (EMT).…”

Clinical benefits of metformin in gynecologic oncology

“…However, the majority of this evidence is based on the results of observational studies. Further, well-conducted, controlled clinical trials are therefore required to verify the beneficial effects of metformin on ovarian cancer survival and prevention (36).…”