A meta-analysis of research in 2013 suggested that Metformin, the type-2 Diabetes drug could increase survival times in cancer patients with type 2 diabetes; this concurred with other studies for endometrial and ovarian.
Metformin is one of the drugs used to lower blood glucose levels in cases of type-2 diabetes. Sadly, patients with Type-2 Diabetes have a greater risk of developing cancer; and shorter survival times. The primary issue seems to be that people with diabetes have poor sugar control. Diabetes is linked to a three fold increased risk of colorectal cancer, for example. And metformin manages that issue.
In Cancer Watch, we have repeatedly covered the problems associated with higher blood glucose levels and the increased risk of cancer, along with reduced survival rates.
In this meta-analysis of 20 papers involving over 13,000 patients (1) and reported by Dr Ming Yin et al in the Oncologist, the conclusion is that metformin helps increase survival times in cancer patients with type-2 Diabetes, better than other plasma glucose-reducing drugs.
Editor of the Oncologist, Bruce Chabner, said this study had removed concerns that metformin might have some causal effect, and that metformin could actually play a part in tumour reduction by helping to lower plasma glucose levels. As we repeatedly tell readers, glucose is the main fuel for a cancer cell.
Other specific studies have shown that metformin increases survival in endometrial cancer (2) and ovarian cancer (3).
However, early research seems to involve only observational studies amongst patients with diabetes. More work is required to understand whether or not metformin works in non-diabetes patients, whether it offers a consistent benefit, exactly what its method of action is with cancer, and if results apply to all cancers.
A study with metformin and Cervical cancer, for example, showed there was no survival benefit (4).
For an up to date full review go to: Metformin and increased cancer survival; a review
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References:
(1) Metformin Is Associated With Survival Benefit in Cancer Patients With Concurrent Type 2 Diabetes: A Systematic Review and Meta-Analysis; Ming Yin et al; 20 November 2013 The Oncologist
(2) Metformin use and endometrial cancer survival; Nicole S Nevadunsky et al; Gynecol Oncol; 2014 Jan;132(1):236-40
(3) Metformin intake is associated with better survival in ovarian cancer: a case-control study; Sanjeev Kumar et al; Cancer; 2013 Feb 1;119(3):555-62.
(4) Association of Metformin Use and Survival Outcome in Women With Cervical Cancer; Tsuyoshi Takiuchi et al; Int J Gynecol Cancer. 2017 Sep; 27(7): 1455–1463.