Pancreatic cancer expresses adiponectin receptors and is associated with hypoleptinemia and hyperadiponectinemia: a case-control study.

Obesity and insulin resistance have been implicated in the etiology of pancreatic cancer (PC). Whether adiponectin and/or leptin, two adipocyte-secreted hormones important in metabolic regulation, are associated with PC pathogenesis and whether adiponectin receptors are expressed in PC remains unknown. In a hospital-based case-control study, we studied 81 cases with incident, histologically confirmed PC and 81 controls matched on gender and age between 2000 and 2007 to investigate the role of adiponectin and leptin adjusting for risk factors linked to PC. In a separate study, we also studied for the first time whether adiponectin receptors 1 and 2 are expressed in PC by studying 16 PC tumor tissue samples which were analyzed using immunohistochemistry. When subjects were divided into control-defined quartiles of adiponectin and leptin, lower leptin but higher adiponectin levels were associated with PC (p = 0.001 and p = 0.05 respectively) before and after controlling for age, gender, BMI, smoking status, alcohol consumption, history of diabetes, and family history of pancreatic cancer. Of the PC tumor tissue samples analyzed, 87.5% had positive or strong positive expression of AdipoR1 and 93.7% had positive or strong positive expression of AdipoR2. Further prospective studies are needed to determine whether the elevated adiponectin and low leptin levels reported in this study reflect compensatory changes during PC progression and thus can be used as markers for PC or whether they are causally implicated in PC.

Association of thyroid disease and thyroid autoimmunity with multiple myeloma risk: a case-control study.

Thyroid disease has been associated with lymphohematopoietic cancer (LHC). No previous study using clinical, sonographic and laboratory data has explored whether thyroid disease and specifically autoimmune thyroid disease (ATD) is associated with multiple myeloma (MM) risk. 73 patients with incident primary MM and 73 hospital controls admitted for non-neoplastic and non-infectious conditions, matched on gender and age were studied between 2001 and 2007. Blood samples were collected. All subjects were submitted to clinical, ultrasound and laboratory thyroid evaluation. The prevalence of clinical thyroid disease in MM patients was significantly higher than in controls (p = 0.002). ATD was associated with increased risk of MM, adjusting for age, gender, body mass index and familial history of LHC [OR = 5.68, 95% confidence interval (CI): 1.69-19.13]. Controlling for the above variables, an individual suffering from any thyroid disease more than 10 years has about 2.41 times more likely the risk to develop MM than an individual without any thyroid disease (OR = 2.41, 95% CI: 1.35-4.29). Also, adjusting for age, gender, BMI and family history of LHC, a familial history of thyroid disease is associated with increased risk of MM (OR = 3.23, 95% CI: 1.25-8.31). Further studies are needed to explore underlying mechanisms associating thyroid autoimmunity with plasma cell transformation.