Background/Objective: Hyperglycemia/hyperinsulinemia promote carcinogenesis. Cancer associated factors worsen insulin resistance. Either way, glycaemic control of cancer bearing diabetic patients often deteriorates, which is believed to help in finding occult cancer in diabetic patients.

Methods: We investigated whether it applies to every type of cancer. We analysed cancer bearing type 2 diabetes patients (T2DM) medical records going back 10 years. HbA1c levels in connection with occult cancer were analysed in relation to organs and stages of cancer based on TMN criteria. Cancers with 20+ diagnosed patients were analysed.

Result: 1155 T2DM patients were newly diagnosed with cancer. Lung cancer totaled 247, colorectal 218, gastric 218, hematologic (leukemia/lymphoma) 81, prostate 75, pancreas 65, hepatocellular 60, kidney or urethro-bladder 49, and uterine 43, breast cancers 32, esophageal 29, gall-bladder/biliary tree 28. No patients were diagnosed with pancreatic cancer at stage 1. The HbA1c of pancreatic cancer patients rose significantly. The HbA1c of lung cancer patients was not elevated even in stage 4, although HbA1c tended to rise significantly as the stage advanced. HbA1c was mildly elevated in almost all stages of colon/rectum and gastric cancer. Gastrointestinal bleeding causes apparent decreases in HbA1c regardless of elevated glycaemic levels in stage 3 and may mask these cancers. HbA1c of hepatocellular carcinoma (HCC) patients decreased with advanced stages.

Discussion: HbA1c elevation can be promising in pancreatic cancer detection. However, lung, prostate, gastrointestinal cancers had little effect on it even in advanced stages with no relation to food intake. Due to masking effects, it was recommended colorectal and gastric cancer patients undergo periodic testing for gastrointestinal bleeding. HCC patients with liver cirrhosis do not have elevated HbA1c levels due to masking effects. The ability to focus on these tests may also save medical expenditure in future. Previous version was presented at EASD.


S. Kaneko: Speaker's Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Mitsubishi Tanabe Pharma Corporation, Novo Nordisk Inc., Sumitomo Dainippon Pharma Co., Ltd. Y. Ueda: None. Y. Tahara: None.

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