Diabetes and Pancreatic Cancer: Chicken or Egg? : Pancreas (original) (raw)

Review

Chicken or Egg?

From the Departments of *Surgery and †Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, Baltimore, MD.

Received for publication April 23, 2010; accepted October 21, 2010.

Reprints: Dana K. Andersen, MD, Department of Surgery, Johns Hopkins Bayview Medical Center, 4940 Eastern Ave, Baltimore, MD 21224 (e-mail: [email protected]).

Presented in part at the combined meeting of the American Pancreatic Association and the Japan Pancreas Society, Honolulu, Hawaii, November 5, 2009.

Abstract

Objectives:

Although half of all patients with pancreatic cancer are diabetic at the time of diagnosis, it remains unclear whether the diabetes associated with pancreatic cancer is a cause or an effect of the malignancy.

Methods:

Epidemiologic studies were reviewed, the geographic prevalence of diabetes and the incidence of pancreatic cancer were examined, and clinical and laboratory studies were reviewed.

Results:

Long-standing diabetes increases the risk of pancreatic cancer by 40% to 100%, and recent-onset diabetes is associated with a 4- to 7-fold increase in risk, such that 1% to 2% of patients with recent-onset diabetes will develop pancreatic cancer within 3 years. Treatment of diabetes or morbid obesity decreases the risk of pancreatic cancer, and metformin therapy decreases the risk due to both its antidiabetic and antineoplastic effects. Recent-onset diabetes associated with pancreatic cancer likely represents secondary or type 3 diabetes. The discrimination of type 3 diabetes from the more prevalent type 2 diabetes may identify the high-risk subgroup of diabetic patients in whom potentially curable pancreatic cancer may be found.

Conclusions:

Type 2 and type 1 diabetes mellitus increase the risk of pancreatic cancer with a latency period of more than 5 years. Type 3 diabetes mellitus is an effect, and therefore a harbinger, of pancreatic cancer in at least 30% of patients.