Study of Serum Leptin in Well-differentiated Thyroid Carcinoma: Correlation with Patient and Tumor Characteristics

BACKGROUND: There is a proven relationship between obesity and several cancers including breast, endometrium, colorectal, and esophagus. With the increasing incidence of both obesity and thyroid cancer, we designed the present study to investigate a causal relationship between leptin, which is one of the well known adipokines, and well-differentiated thyroid cancer (WDTC). METHODS: Serum leptin levels were measured in 30 patients with WDTC and compared to 30 healthy control subjects before and 1 month after surgery. Other parameters studied included age, sex, body mass index, menopausal status in women, lymph node status, tumor size, and disease multifocality. RESULTS: There were no differences between the two groups regarding age and sex. Preoperative leptin levels were higher in the WDTC patients when compared to the control patients [19.25 (1.50–109.60) vs 0.90 (0.50–11.80) ng/ml, p < 0.001, group 1 vs group 2, respectively]. A significant drop in leptin levels 1 month after surgery occurred in the WDTC group, falling from 19.25 (1.50–109.60) to 0.90 (0.60–8.90) ng/ml (p < 0.001). This did not occur in the control group (p = 0.274). Lymph node involvement, tumor size, and multifocality had no effect on leptin levels, although trends were observed (p = 0.48, 0.079, and 0.064), respectively. CONCLUSIONS: Serum leptin levels were significantly higher in WDTC patients when compared to control group patients, with a significant drop after surgery. Leptin may play a role in diagnosis of WDTC; however, its prognostic value is still undetermined.