Hey @susu2, I sent your question to Dr. Dawn Mussallem. She was delayed in her response due to some pressing deadlines, but she just sent her response:
So your question, does diabetes cause cancer….

Type 2 diabetes either on its own and when combined with being either overweight or obese is associated with an increased risk for several cancers, including colon, gallbladder, pancreatic, liver, esophageal, postmenopausal breast, ovarian, endometrial, renal, bladder, and thyroid cancers, non-Hodgkins lymphoma and multiple myeloma. Lifestyle factors including dietary intake, physical activity, and body fatness appear to promote or inhibit cancer development.

Here are some healthy living suggestions:

--It is important to eat a low fat, sugar free diet rich in whole foods including an abundance of vegetables, non-sweet fruit especially berries, whole grains that are high in fiber, legumes, low fat dairy, and fish. Avoid anything white, this includes sugar, white flour, white potatoes, white rice, etc. Also avoid processed meat and try to reduce consumption of red meat too. Include healthy fats in your diet such as extra virgin olive oil, avocado and a small serving of nuts especially walnuts, almonds, and cashews. But if you are overweight/ obese, don’t eat too many nuts because these are high in calories.

--Be active. Move your body every single day!

--Practice relaxation/ deep breathing exercises, pray and/or meditate 10-20 minutes every day.

--Good sleep hygiene is important, aim for 7 hours sleep a night.

Lastly, you mention that you take a statin and metformin. Studies suggest both these medications have favorable benefits in patients with cancer!