I'm struck by the comment at the beginning of the article about "avoiding excessive fat..."  it doesn't have anything to do w/ blood-sugar levels in this article.  I find this commonly accepted reference to fat unfortunate.   (emphasis mine)
Kath 

High Blood Sugar Tied to Increased Cancer Risk 
Results of a study involving nearly 65,000 people point to an association between cancer and abnormally high blood-sugar levels. 

These results "have obvious implications for lifestyle guidance, as it is well known what factors cause blood glucose increases," Dr. Par Stattin from Umea University Medical Center, Sweden noted in comments to Reuters Health. 

By avoiding excessive fat and other dietary risk factors, and by getting regular exercise, "you can decrease your risk of cardiovascular disease, diabetes — and cancer," he added. 

Type 2 diabetes is associated with an increased risk of liver, pancreas, colon cancer, as well as other cancers, Stattin and colleagues note in the journal Diabetes Care. However, less is known about the effect on cancer risk associated with moderately elevated blood sugar levels among non-diabetic subjects. 

To investigate further, the researchers examined data from 31,304 men and 33,293 women who participated in a larger study and had glucose (blood sugar) measurements available. In total 2,478 cases of cancer were identified in this group. 

In women, the total cancer risk increased with rising blood sugar levels. The relative risk of cancer was 26 percent higher for women with the highest fasting blood sugar compared with women with the lowest fasting blood sugar. 

Adjustment for errors in measurement further increased the relative risk of cancer for women with abnormally high blood-sugar levels. 

Overall, there was no significant association between total cancer risk and blood sugar measurements in men. 

However, for men and women, high fasting glucose was significantly associated with an increased risk of cancer of the pancreas, endometrium, urinary tract, and malignant melanoma. 

These associations were independent of body weight. 

These findings, the authors say, provide "further evidence for an association between abnormal glucose metabolism and cancer." 

© Reuters