Challenges of imaging for cancer in patients with diabetes and obesity.

A growing body of evidence supports a connection among diabetes (predominantly type 2), obesity, and cancer. Multiple meta-analyses of epidemiological data show that people with diabetes are at increased risk of developing a variety of different cancers and suffer from an increased rate of perioperative complications and cancer mortality. Computed tomography (CT) has played an important role in diagnosis and staging of cancer. Positron emission tomography is complementary to CT in the diagnosis, staging, and evaluation of treatment response for many types of cancer. Because of generally poor clinical outcome of cancers when they are detected in late stages, more research is now focused on stratifying risk to allow personalized screening of at-risk patients and cancer detection at an earlier stage. In this review, we summarize basic noninvasive imaging techniques currently in use to detect cancer with emphasis on the challenges of imaging for early cancer detection in obese patients with diabetes.