Despite a higher incidence and less favorable outcome of malignant tumors in obese patients, much less recognized is the link between obesity and cancer. The mechanism of the association of obesity with carcinogenesis remains incompletely understood. Postulated mechanisms include insulin resistance, insulin-like growth factor signaling, chronic inflammation, immunomodulation, hyperglycemia-induced oxidative stress, and changes of intestinal microbiome. Insulin resistance leads to direct mitogenic and antiapoptotic signaling by insulin and the insulin-like growth factor axis. Obesity can be considered to be a state of chronic low-grade inflammation. In obesity, numerous proinflammatory cytokines are released from adipose tissue which may involve in carcinogenesis. Hyperglycemia in susceptible cells results in the overproduction of superoxide and this process is the key to initiating all damaging pathways related to diabetes. This hyperglycemia-induced oxidative stress could be one possible link among obesity, diabetes, and cancer development. The role of obesity-related changes in the intestinal microbiome in gastrointestinal carcinogenesis deserves further attention.
Adipokines/metabolism/physiology ; Gastrointestinal Neoplasms/*etiology/microbiology ; Humans ; Inflammation/etiology ; Insulin/metabolism/physiology ; Leptin/metabolism/physiology ; Obesity/*complications/immunology/metabolism ; Oxidative Stress ; Somatomedins/metabolism/physiology

Intrahepatic abscess is an unusual complication of peptic ulcer disease. We present a case of gastric cancer in which the ulcer penetrated into the left lobe of liver with subsequent abscess and fistula formation. Esophagogastroduodenoscopy confirmed ulcers and a fistula opening in the antrum. Abdominal computed tomogram showed a subcapsular liver abscess adjacent to the gastric antrum. Subtotal gastrectomy with curettage of the fistulous tract was performed. The final diagnosis was the signet ring cell gastric carcinoma complicating subcapsular liver abscess. To our knowledge, this is the first reported case in Korea.
Endoscopy, Gastrointestinal ; Female ; Humans ; Klebsiella pneumoniae/isolation & purification ; Liver Abscess/diagnosis/*etiology/microbiology ; Middle Aged ; Peptic Ulcer Perforation/*complications/diagnosis ; Stomach Neoplasms/complications/*diagnosis/surgery ; Tomography, X-Ray Computed